Merge from dev of tools changes

16 files changed, 3192 insertions, 3665 deletions

diff --git a/tools/lib/h5diff.c b/tools/lib/h5diff.c
index 945444a..15da7d3 100644
--- a/tools/lib/h5diff.c
+++ b/tools/lib/h5diff.c
@@ -29,7 +29,7 @@
 H5_ATTR_PURE int
 print_objname (diff_opt_t * opts, hsize_t nfound)
 {
-    return ((opts->m_verbose || nfound) && !opts->m_quiet) ? 1 : 0;
+    return ((opts->mode_verbose || nfound) && !opts->mode_quiet) ? 1 : 0;
 }
 
 /*-------------------------------------------------------------------------
@@ -45,7 +45,7 @@ do_print_objname (const char *OBJ, const char *path1, const char *path2, diff_op
      * displaying any object or symbolic links. This improves
      * readability of the output.
      */
-    if (opts->m_verbose_level >= 1)
+    if (opts->mode_verbose_level >= 1)
         parallel_print("\n");
     parallel_print("%-7s: <%s> and <%s>\n", OBJ, path1, path2);
 }
@@ -74,7 +74,7 @@ do_print_attrname (const char *attr, const char *path1, const char *path2)
 static int
 print_warn(diff_opt_t *opts)
 {
-    return ((opts->m_verbose)) ? 1: 0;
+    return ((opts->mode_verbose)) ? 1: 0;
 }
 
 
@@ -141,7 +141,7 @@ is_valid_options(diff_opt_t *opts)
 
     /*-----------------------------------------------
      * no -q(quiet) with -v (verbose) or -r (report) */
-    if(opts->m_quiet && (opts->m_verbose || opts->m_report)) {
+    if(opts->mode_quiet && (opts->mode_verbose || opts->mode_report)) {
         parallel_print("Error: -q (quiet mode) cannot be added to verbose or report modes\n");
         opts->err_stat = H5DIFF_ERR;
         H5TOOLS_GOTO_DONE(0);
@@ -169,9 +169,9 @@ done:
  *           0 - not excluded path
  *------------------------------------------------------------------------*/
 static int
-is_exclude_path (char * path, h5trav_type_t type, diff_opt_t *opts)
+is_exclude_path (char *path, h5trav_type_t type, diff_opt_t *opts)
 {
-    struct exclude_path_list * exclude_path_ptr;
+    struct exclude_path_list *exclude_path_ptr;
     int   ret_cmp;
     int   ret_value = 0;
 
@@ -210,7 +210,7 @@ is_exclude_path (char * path, h5trav_type_t type, diff_opt_t *opts)
             if (ret_cmp == 0) {  /* found matching object */
                 /* excluded non-group object */
                 ret_value = 1;
-                /* remember the type of this maching object.
+                /* remember the type of this matching object.
                  * if it's group, it can be used for excluding its member
                  * objects in this while() loop */
                 exclude_path_ptr->obj_type = type;
@@ -224,6 +224,71 @@ done:
     return  ret_value;
 }
 
+/*-------------------------------------------------------------------------
+ * Function: is_exclude_attr
+ *
+ * Purpose:  check if 'paths' are part of exclude path list
+ *
+ * Return:
+ *           1 - excluded path
+ *           0 - not excluded path
+ *------------------------------------------------------------------------*/
+static int
+is_exclude_attr (char *path, h5trav_type_t type, diff_opt_t *opts)
+{
+    struct exclude_path_list *exclude_ptr;
+    int   ret_cmp;
+    int   ret_value = 0;
+
+    /* check if exclude attr option is given */
+    if (!opts->exclude_attr_path)
+        H5TOOLS_GOTO_DONE(0);
+
+    /* assign to local exclude list pointer */
+    exclude_ptr = opts->exclude_attr;
+
+    /* search objects in exclude list */
+    while (NULL != exclude_ptr) {
+        /* if exclude path is is group, exclude its members as well */
+        if (exclude_ptr->obj_type == H5TRAV_TYPE_GROUP) {
+            ret_cmp = HDstrncmp(exclude_ptr->obj_path, path,
+                                HDstrlen(exclude_ptr->obj_path));
+            if (ret_cmp == 0) {  /* found matching members */
+                size_t len_grp;
+
+                /* check if given path belong to an excluding group, if so
+                 * exclude it as well.
+                 * This verifies if “/grp1/dset1” is only under “/grp1”, but
+                 * not under “/grp1xxx/” group.
+                 */
+                len_grp = HDstrlen(exclude_ptr->obj_path);
+                if (path[len_grp] == '/') {
+                    /* belong to excluded group! */
+                    ret_value = 1;
+                    break;  /* while */
+                }
+            }
+        }
+        /* exclude target is not group, just exclude the object */
+        else {
+            ret_cmp = HDstrcmp(exclude_ptr->obj_path, path);
+            if (ret_cmp == 0) {  /* found matching object */
+                /* excluded non-group object */
+                ret_value = 1;
+                /* remember the type of this matching object.
+                 * if it's group, it can be used for excluding its member
+                 * objects in this while() loop */
+                exclude_ptr->obj_type = type;
+                break; /* while */
+            }
+        }
+        exclude_ptr = exclude_ptr->next;
+    }
+
+done:
+    return  ret_value;
+}
+
 
 /*-------------------------------------------------------------------------
  * Function: free_exclude_path_list
@@ -243,6 +308,25 @@ free_exclude_path_list(diff_opt_t *opts)
     }
 }
 
+
+/*-------------------------------------------------------------------------
+ * Function: free_exclude_attr_list
+ *
+ * Purpose:  free exclude object attribute list from diff options
+ *------------------------------------------------------------------------*/
+static void
+free_exclude_attr_list(diff_opt_t *opts)
+{
+    struct exclude_path_list *curr = opts->exclude_attr;
+    struct exclude_path_list *next;
+
+    while (NULL != curr) {
+        next = curr->next;
+        HDfree(curr);
+        curr = next;
+    }
+}
+
 /*-------------------------------------------------------------------------
  * Function: build_match_list
  *
@@ -288,6 +372,7 @@ build_match_list (const char *objname1, trav_info_t *info1, const char *objname2
      * All the objects belong to given groups are the candidates.
      * So prepare to compare paths without the group names.
      */
+    H5TOOLS_DEBUG("objname1 = %s objname2 = %s ", objname1, objname2);
 
     /* if obj1 is not root */
     if (HDstrcmp (objname1,"/") != 0)
@@ -421,8 +506,8 @@ trav_grp_symlinks(const char *path, const H5L_info_t *linfo, void *udata)
                 H5TOOLS_GOTO_DONE(FAIL);
             }
             else if (ret_value == 0) {
-             /* no dangling link option given and detect dangling link */
-               tinfo->symlink_visited.dangle_link = TRUE;
+                /* no dangling link option given and detect dangling link */
+                tinfo->symlink_visited.dangle_link = TRUE;
                 trav_info_visit_lnk(path, linfo, tinfo);
                 if (opts->no_dangle_links)
                     opts->err_stat = H5DIFF_ERR; /* make dangling link is error */
@@ -560,17 +645,17 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
     *-------------------------------------------------------------------------
     */
     /* open file 1 */
-    if((file1_id = h5tools_fopen(fname1, H5F_ACC_RDONLY, H5P_DEFAULT, NULL, NULL, (size_t)0)) < 0) {
+    if((file1_id = h5tools_fopen(fname1, H5F_ACC_RDONLY, H5P_DEFAULT, FALSE, NULL, (size_t)0)) < 0) {
         parallel_print("h5diff: <%s>: unable to open file\n", fname1);
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "<%s>: unable to open file\n", fname1);
-    } /* end if */
+    }
     H5TOOLS_DEBUG("file1_id = %s", fname1);
 
     /* open file 2 */
-    if((file2_id = h5tools_fopen(fname2, H5F_ACC_RDONLY, H5P_DEFAULT, NULL, NULL, (size_t)0)) < 0) {
+    if((file2_id = h5tools_fopen(fname2, H5F_ACC_RDONLY, H5P_DEFAULT, FALSE, NULL, (size_t)0)) < 0) {
         parallel_print("h5diff: <%s>: unable to open file\n", fname2);
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "<%s>: unable to open file\n", fname2);
-    } /* end if */
+    }
     H5TOOLS_DEBUG("file2_id = %s", fname2);
 
     /*-------------------------------------------------------------------------
@@ -600,6 +685,7 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
         }
         else
             obj1fullname = HDstrdup(objname1);
+        H5TOOLS_DEBUG("obj1fullname = %s", obj1fullname);
 
         /* make the given object2 fullpath, start with "/" */
         if (HDstrncmp(objname2, "/", 1)) {
@@ -617,6 +703,7 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
         }
         else
             obj2fullname = HDstrdup(objname2);
+        H5TOOLS_DEBUG("obj2fullname = %s", obj2fullname);
 
         /*----------------------------------------------------------
          * check if obj1 is root, group, single object or symlink
@@ -750,12 +837,12 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
             H5TOOLS_DEBUG("h5diff ... dangling link");
             if (opts->no_dangle_links) {
                 /* treat dangling link as error */
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     parallel_print("Warning: <%s> is a dangling link.\n", obj1fullname);
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "treat dangling link as error");
             }
             else {
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     parallel_print("obj1 <%s> is a dangling link.\n", obj1fullname);
                 if (l_ret1 != 0 ||  l_ret2 != 0) {
                     nfound++;
@@ -791,12 +878,12 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
             H5TOOLS_DEBUG("h5diff ... dangling link");
             if (opts->no_dangle_links) {
                 /* treat dangling link as error */
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     parallel_print("Warning: <%s> is a dangling link.\n", obj2fullname);
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "treat dangling link as error");
             }
             else {
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     parallel_print("obj2 <%s> is a dangling link.\n", obj2fullname);
                 if (l_ret1 != 0 || l_ret2 != 0) {
                     nfound++;
@@ -830,8 +917,8 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
     * comparing details of same objects.
     */
 
-    if(!(opts->m_verbose || opts->m_report)) {
-        H5TOOLS_DEBUG("h5diff NOT (opts->m_verbose || opts->m_report)");
+    if(!(opts->mode_verbose || opts->mode_report)) {
+        H5TOOLS_DEBUG("h5diff NOT (opts->mode_verbose || opts->mode_report)");
         /* if no danglink links */
         if (l_ret1 > 0 && l_ret2 > 0)
             if (h5tools_is_obj_same(file1_id, obj1fullname, file2_id, obj2fullname) != 0)
@@ -897,9 +984,14 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
         /*------------------------------------------------------
          * print the list
          */
-         if(opts->m_verbose) {
+         if(opts->mode_verbose) {
              unsigned u;
 
+             if(opts->mode_verbose_level > 2) {
+                parallel_print("file1: %s\n", fname1);
+                parallel_print("file2: %s\n", fname2);
+             }
+
              parallel_print("\n");
              /* if given objects is group under root */
              if (HDstrcmp (obj1fullname,"/") || HDstrcmp (obj2fullname,"/"))
@@ -920,6 +1012,7 @@ h5diff(const char *fname1, const char *fname2, const char *objname1, const char
     nfound = diff_match(file1_id, obj1fullname, info1_lp,
                         file2_id, obj2fullname, info2_lp,
                         match_list, opts);
+    H5TOOLS_DEBUG("diff_match nfound: %d - errstat:%d", nfound, opts->err_stat);
 
 done:
     opts->err_stat = opts->err_stat | ret_value;
@@ -1016,12 +1109,14 @@ diff_match(hid_t file1_id, const char *grp1, trav_info_t *info1,
      *-------------------------------------------------------------------------
      */
 
+    H5TOOLS_DEBUG("exclude_path opts->contents:%d", opts->contents);
     /* not valid compare used when --exclude-path option is used */
     if (!opts->exclude_path) {
         /* number of different objects */
         if (info1->nused != info2->nused) {
             opts->contents = 0;
         }
+        H5TOOLS_DEBUG("opts->exclude_path opts->contents:%d", opts->contents);
     }
 
     /* objects in one file and not the other */
@@ -1030,6 +1125,7 @@ diff_match(hid_t file1_id, const char *grp1, trav_info_t *info1,
             opts->contents = 0;
             break;
         }
+        H5TOOLS_DEBUG("table->nobjs[%d] opts->contents:%d", i, opts->contents);
     }
 
     /*-------------------------------------------------------------------------
@@ -1102,9 +1198,7 @@ diff_match(hid_t file1_id, const char *grp1, trav_info_t *info1,
             opts->cmn_objs = 1;
             if(!g_Parallel) {
                 H5TOOLS_DEBUG("diff paths - errstat:%d", opts->err_stat);
-                nfound += diff(file1_id, obj1_fullpath,
-                               file2_id, obj2_fullpath,
-                            opts, &argdata);
+                nfound += diff(file1_id, obj1_fullpath, file2_id, obj2_fullpath, opts, &argdata);
             } /* end if */
 #ifdef H5_HAVE_PARALLEL
             else {
@@ -1349,6 +1443,8 @@ diff_match(hid_t file1_id, const char *grp1, trav_info_t *info1,
 
     opts->err_stat = opts->err_stat | ret_value;
 
+    free_exclude_attr_list (opts);
+
     /* free table */
     if (table)
         trav_table_free(table);
@@ -1373,7 +1469,7 @@ diff_match(hid_t file1_id, const char *grp1, trav_info_t *info1,
  *-------------------------------------------------------------------------
  */
 hsize_t
-diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_opt_t * opts, diff_args_t *argdata)
+diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_opt_t *opts, diff_args_t *argdata)
 {
     int           status = -1;
     hid_t         dset1_id = H5I_INVALID_HID;
@@ -1422,7 +1518,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
         if (status == 0) {
             if (opts->no_dangle_links) {
                 /* dangling link is error */
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     parallel_print("Warning: <%s> is a dangling link.\n", path1);
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "dangling link is error");
             }
@@ -1437,7 +1533,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
         if (status == 0) {
             if (opts->no_dangle_links) {
                 /* dangling link is error */
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     parallel_print("Warning: <%s> is a dangling link.\n", path2);
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "dangling link is error");
             }
@@ -1463,11 +1559,11 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
     /* if objects are not the same type */
     if (argdata->type[0] != argdata->type[1]) {
         H5TOOLS_DEBUG("diff objects are not the same");
-        if (opts->m_verbose||opts->m_list_not_cmp) {
+        if (opts->mode_verbose||opts->mode_list_not_cmp) {
             parallel_print("Not comparable: <%s> is of type %s and <%s> is of type %s\n",
-            path1, get_type(argdata->type[0]),
-            path2, get_type(argdata->type[1]));
+                    path1, get_type(argdata->type[0]), path2, get_type(argdata->type[1]));
         }
+
         opts->not_cmp = 1;
         /* TODO: will need to update non-comparable is different
          * opts->contents = 0;
@@ -1492,7 +1588,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
                         object_type == H5TRAV_TYPE_GROUP);
         if (opts->follow_links || is_hard_link) {
             /* print information is only verbose option is used */
-            if(opts->m_verbose || opts->m_report) {
+            if(opts->mode_verbose || opts->mode_report) {
                 switch(object_type) {
                     case H5TRAV_TYPE_DATASET:
                         do_print_objname("dataset", path1, path2, opts);
@@ -1521,7 +1617,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
                 } /* switch(type)*/
 
                 print_found(nfound);
-            } /* if(opts->m_verbose || opts->m_report) */
+            } /* if(opts->mode_verbose || opts->mode_report) */
 
             /* exact same, so comparison is done */
             H5TOOLS_GOTO_DONE(H5DIFF_NO_ERR);
@@ -1539,15 +1635,16 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dopen2 failed");
             if((dset2_id = H5Dopen2(file2_id, path2, H5P_DEFAULT)) < 0)
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dopen2 failed");
+            H5TOOLS_DEBUG("paths: %s - %s", path1, path2);
             /* verbose (-v) and report (-r) mode */
-            if(opts->m_verbose || opts->m_report) {
+            if(opts->mode_verbose || opts->mode_report) {
                 do_print_objname("dataset", path1, path2, opts);
                 H5TOOLS_DEBUG("call diff_dataset 1:%s  2:%s ", path1, path2);
                 nfound = diff_dataset(file1_id, file2_id, path1, path2, opts);
                 print_found(nfound);
             }
             /* quiet mode (-q), just count differences */
-            else if(opts->m_quiet) {
+            else if(opts->mode_quiet) {
                 nfound = diff_dataset(file1_id, file2_id, path1, path2, opts);
             }
             /* the rest (-c, none, ...) */
@@ -1567,7 +1664,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
              * referenced object
              *---------------------------------------------------------
              */
-            if(path1) {
+            if(path1 && !is_exclude_attr(path1, object_type, opts)) {
                 H5TOOLS_DEBUG( "call diff_attr 1:%s  2:%s ", path1, path2);
                 nfound += diff_attr(dset1_id, dset2_id, path1, path2, opts);
             }
@@ -1599,7 +1696,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
                 do_print_objname("datatype", path1, path2, opts);
 
             /* always print the number of differences found in verbose mode */
-            if(opts->m_verbose)
+            if(opts->mode_verbose)
                 print_found(nfound);
 
             /*-----------------------------------------------------------------
@@ -1608,7 +1705,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
              * referenced object
              *-----------------------------------------------------------------
              */
-            if(path1) {
+            if(path1 && !is_exclude_attr(path1, object_type, opts)) {
                 H5TOOLS_DEBUG("call diff_attr 1:%s  2:%s ", path1, path2);
                 nfound += diff_attr(type1_id, type2_id, path1, path2, opts);
             }
@@ -1629,7 +1726,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
                 do_print_objname("group", path1, path2, opts);
 
             /* always print the number of differences found in verbose mode */
-            if(opts->m_verbose)
+            if(opts->mode_verbose)
                 print_found(nfound);
 
             if((grp1_id = H5Gopen2(file1_id, path1, H5P_DEFAULT)) < 0)
@@ -1643,7 +1740,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
              * referenced object
              *-----------------------------------------------------------------
              */
-            if(path1) {
+            if(path1 && !is_exclude_attr(path1, object_type, opts)) {
                 H5TOOLS_DEBUG("call diff_attr 1:%s  2:%s ", path1, path2);
                 nfound += diff_attr(grp1_id, grp2_id, path1, path2, opts);
             }
@@ -1671,7 +1768,7 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
                     do_print_objname("link", path1, path2, opts);
 
                 /* always print the number of differences found in verbose mode */
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     print_found(nfound);
                 }
             break;
@@ -1721,14 +1818,14 @@ diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_
                 } /* end else */
 
                 /* always print the number of differences found in verbose mode */
-                if(opts->m_verbose)
+                if(opts->mode_verbose)
                     print_found(nfound);
             }
             break;
 
         case H5TRAV_TYPE_UNKNOWN:
         default:
-            if(opts->m_verbose)
+            if(opts->mode_verbose)
                 parallel_print("Comparison not supported: <%s> and <%s> are of type %s\n",
                     path1, path2, get_type(object_type) );
             opts->not_cmp = 1;
@@ -1750,7 +1847,7 @@ done:
     }
     /* path1 is dangling link */
     else if (is_dangle_link1) {
-        if(opts->m_verbose)
+        if(opts->mode_verbose)
            parallel_print("obj1 <%s> is a dangling link.\n", path1);
         nfound++;
         if(print_objname(opts, nfound))
@@ -1758,7 +1855,7 @@ done:
     }
     /* path2 is dangling link */
     else if (is_dangle_link2) {
-        if(opts->m_verbose)
+        if(opts->mode_verbose)
             parallel_print("obj2 <%s> is a dangling link.\n", path2);
         nfound++;
         if(print_objname(opts, nfound))
diff --git a/tools/lib/h5diff.h b/tools/lib/h5diff.h
index b04ec23..0209d31 100644
--- a/tools/lib/h5diff.h
+++ b/tools/lib/h5diff.h
@@ -15,25 +15,9 @@
 #define H5DIFF_H__
 
 #include "hdf5.h"
+#include "h5tools.h"
 #include "h5trav.h"
 
-/*
- * Debug printf macros. The prefix allows output filtering by test scripts.
- */
-#ifdef H5DIFF_DEBUG
-#define h5difftrace(x) HDfprintf(stderr, "h5diff debug: " x)
-#define h5diffdebug2(x1, x2) HDfprintf(stderr, "h5diff debug: " x1, x2)
-#define h5diffdebug3(x1, x2, x3) HDfprintf(stderr, "h5diff debug: " x1, x2, x3)
-#define h5diffdebug4(x1, x2, x3, x4) HDfprintf(stderr, "h5diff debug: " x1, x2, x3, x4)
-#define h5diffdebug5(x1, x2, x3, x4, x5) HDfprintf(stderr, "h5diff debug: " x1, x2, x3, x4, x5)
-#else
-#define h5difftrace(x)
-#define h5diffdebug2(x1, x2)
-#define h5diffdebug3(x1, x2, x3)
-#define h5diffdebug4(x1, x2, x3, x4)
-#define h5diffdebug5(x1, x2, x3, x4, x5)
-#endif
-
 #define MAX_FILENAME 1024
 
 /*-------------------------------------------------------------------------
@@ -52,11 +36,12 @@ typedef struct {
  */
 /* linked list to keep exclude path list */
 struct exclude_path_list {
-    char  *obj_path;
-    h5trav_type_t obj_type;
-    struct exclude_path_list * next;
+    const char                 *obj_path;
+    h5trav_type_t               obj_type;
+    struct exclude_path_list   *next;
 };
 
+
 /* Enumeration value for keeping track of whether an error occurred or differences were found */
 typedef enum {
     H5DIFF_NO_ERR,   /* No error occurred */
@@ -65,27 +50,45 @@ typedef enum {
 } diff_err_t;
 
 typedef struct {
-    int        m_quiet;               /* quiet mode: no output at all */
-    int        m_report;              /* report mode: print the data */
-    int        m_verbose;             /* verbose mode: print the data, list of objcets, warnings */
-    int        m_verbose_level;       /* control verbose details */
-    int        d;                     /* delta, absolute value to compare */
-    double     delta;                 /* delta value */
-    int        p;                     /* relative error to compare*/
-    int        use_system_epsilon;    /* flag to use system epsilon (1 or 0) */
-    double     percent;               /* relative error value */
-    int        n;                     /* count, compare up to count */
-    hsize_t    count;                 /* count value */
-    hbool_t    follow_links;          /* follow symbolic links */
-    int        no_dangle_links;       /* return error when find dangling link */
-    diff_err_t err_stat;              /* an error ocurred (2, error, 1, differences, 0, no error) */
-    int        cmn_objs;              /* do we have common objects */
-    int        not_cmp;               /* are the objects comparable */
-    int        contents;              /* equal contents */
-    int        do_nans;               /* consider Nans while diffing floats */
-    int        m_list_not_cmp;        /* list not comparable messages */
-    int        exclude_path;          /* exclude path to an object */
-    struct     exclude_path_list * exclude; /* keep exclude path list */
+    int        mode_quiet;                 /* quiet mode: no output at all */
+    int        mode_report;                /* report mode: print the data */
+    int        mode_verbose;               /* verbose mode: print the data, list of objcets, warnings */
+    int        mode_verbose_level;         /* control verbose details */
+    int        mode_list_not_cmp;          /* list not comparable messages */
+    int        print_header;               /* print header */
+    int        print_percentage;           /* print percentage */
+    int        delta_bool;                 /* delta, absolute value to compare */
+    double     delta;                      /* delta value */
+    int        use_system_epsilon;         /* flag to use system epsilon (1 or 0) */
+    int        percent_bool;               /* relative error to compare*/
+    double     percent;                    /* relative error value */
+    hbool_t    follow_links;               /* follow symbolic links */
+    int        no_dangle_links;            /* return error when find dangling link */
+    int        cmn_objs;                   /* do we have common objects */
+    int        not_cmp;                    /* are the objects comparable */
+    int        contents;                   /* equal contents */
+    int        do_nans;                    /* consider Nans while diffing floats */
+    int        exclude_path;               /* exclude path to an object */
+    int        exclude_attr_path;          /* exclude path to an object */
+    struct     exclude_path_list *exclude; /* keep exclude path list */
+    struct     exclude_path_list *exclude_attr; /* keep exclude attribute list */
+    int        count_bool;                 /* count, compare up to count */
+    hsize_t    count;                      /* count value */
+    diff_err_t err_stat;                   /* an error ocurred (2, error, 1, differences, 0, no error) */
+    hsize_t    nelmts;                     /* total number of elements */
+    hsize_t    hs_nelmts;                  /* number of elements to read at a time*/
+    int        rank;                       /* dimensionality */
+    size_t     m_size;                     /* m_size for diff */
+    hid_t      m_tid;                      /* m_tid for diff */
+    hsize_t    dims[H5S_MAX_RANK];         /* dimensions of object */
+    hsize_t    p_min_idx[H5S_MAX_RANK];    /* min selected index */
+    hsize_t    p_max_idx[H5S_MAX_RANK];    /* max selected index */
+    hsize_t    acc[H5S_MAX_RANK];          /* accumulator position */
+    hsize_t    pos[H5S_MAX_RANK];          /* matrix position */
+    hsize_t    sm_pos[H5S_MAX_RANK];       /* stripmine position */
+    char       *obj_name[2];               /* name for object */
+    struct     subset_t *sset[2];          /* subsetting parameters */
+    hbool_t    custom_vol[2];              /* Using a custom input, output VOL? */
 } diff_opt_t;
 
 
@@ -98,18 +101,9 @@ typedef struct {
 extern "C" {
 #endif
 
-H5TOOLS_DLL hsize_t  h5diff(const char *fname1,
-                const char *fname2,
-                const char *objname1,
-                const char *objname2,
-                diff_opt_t *opts);
+H5TOOLS_DLL hsize_t h5diff(const char *fname1, const char *fname2, const char *objname1, const char *objname2, diff_opt_t *opts);
 
-H5TOOLS_DLL hsize_t diff( hid_t      file1_id,
-              const char *path1,
-              hid_t      file2_id,
-              const char *path2,
-              diff_opt_t *opts,
-              diff_args_t *argdata);
+H5TOOLS_DLL hsize_t diff(hid_t file1_id, const char *path1, hid_t file2_id, const char *path2, diff_opt_t *opts, diff_args_t *argdata);
 
 #ifdef H5_HAVE_PARALLEL
 H5TOOLS_DLL void phdiff_dismiss_workers(void);
@@ -128,63 +122,29 @@ H5TOOLS_DLL void print_manager_output(void);
  */
 
 
-hsize_t diff_dataset( hid_t file1_id,
-                      hid_t file2_id,
-                      const char *obj1_name,
-                      const char *obj2_name,
-                      diff_opt_t *opts);
-
-hsize_t diff_datasetid( hid_t dset1_id,
-                        hid_t dset2_id,
-                        const char *obj1_name,
-                        const char *obj2_name,
-                        diff_opt_t *opts);
-
-
-hsize_t diff_match( hid_t file1_id, const char *grp1, trav_info_t *info1,
-                    hid_t file2_id, const char *grp2, trav_info_t *info2,
-                    trav_table_t *table, diff_opt_t *opts );
-
-hsize_t diff_array( void *_mem1,
-                    void *_mem2,
-                    hsize_t nelmts,
-                    hsize_t hyper_start,
-                    int rank,
-                    hsize_t *dims,
-                    diff_opt_t *opts,
-                    const char *name1,
-                    const char *name2,
-                    hid_t m_type,
-                    hid_t container1_id,
-                    hid_t container2_id); /* dataset where the reference came from*/
-
-
-int diff_can_type( hid_t       f_type1, /* file data type */
-                   hid_t       f_type2, /* file data type */
-                   int         rank1,
-                   int         rank2,
-                   hsize_t     *dims1,
-                   hsize_t     *dims2,
-                   hsize_t     *maxdim1,
-                   hsize_t     *maxdim2,
-                   const char  *obj1_name,
-                   const char  *obj2_name,
-                   diff_opt_t  *opts,
-                   int         is_compound);
-
-hsize_t diff_attr_data(hid_t attr1_id,
-                  hid_t attr2_id,
-                  const char *attr1_name,
-                  const char *attr2_name,
-                  const char *path1,
-                  const char *path2,
-                  diff_opt_t *opts);
-
-hsize_t diff_attr(hid_t loc1_id,
-                  hid_t loc2_id,
-                  const char *path1,
-                  const char *path2,
-                  diff_opt_t *opts);
+hsize_t diff_dataset(hid_t file1_id, hid_t file2_id,
+                     const char *obj1_name, const char *obj2_name, diff_opt_t *opts);
+
+hsize_t diff_datasetid(hid_t dset1_id, hid_t dset2_id,
+                       const char *obj1_name, const char *obj2_name, diff_opt_t *opts);
+
+
+hsize_t diff_match(hid_t file1_id, const char *grp1, trav_info_t *info1,
+                   hid_t file2_id, const char *grp2, trav_info_t *info2,
+                   trav_table_t *table, diff_opt_t *opts);
+
+hsize_t diff_array(void *_mem1, void *_mem2,
+                   diff_opt_t *opts, hid_t container1_id, hid_t container2_id);
+
+int diff_can_type(hid_t f_type1, hid_t f_type2, int rank1, int rank2,
+                  hsize_t *dims1, hsize_t *dims2, hsize_t *maxdim1, hsize_t *maxdim2,
+                  diff_opt_t *opts, int is_compound);
+
+hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id, const char *name1, const char *name2,
+                    const char *path1, const char *path2, diff_opt_t *opts);
+
+hsize_t diff_attr(hid_t loc1_id, hid_t loc2_id,
+                  const char *path1, const char *path2, diff_opt_t *opts);
 
 
 /*-------------------------------------------------------------------------
diff --git a/tools/lib/h5diff_array.c b/tools/lib/h5diff_array.c
index fc5b97a..f46dc73 100644
--- a/tools/lib/h5diff_array.c
+++ b/tools/lib/h5diff_array.c
@@ -132,97 +132,39 @@ typedef struct mcomp_t {
  * local prototypes
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_region(hid_t obj1_id, hid_t obj2_id, hid_t region1_id,
-        hid_t region2_id, diff_opt_t *opts);
 static hbool_t all_zero(const void *_mem, size_t size);
 static int ull2float(unsigned long long ull_value, float *f_value);
-static hsize_t character_compare(char *mem1, char *mem2, hsize_t i, size_t u,
-        int rank, hsize_t *dims, hsize_t *acc, hsize_t *pos,
-        diff_opt_t *opts, const char *obj1, const char *obj2, int *ph);
-static hsize_t character_compare_opt(unsigned char *mem1, unsigned char *mem2,
-        hsize_t i, int rank, hsize_t *dims, hsize_t *acc, hsize_t *pos,
-        diff_opt_t *opts, const char *obj1, const char *obj2, int *ph);
+static hsize_t character_compare(char *mem1, char *mem2, hsize_t elemtno, ssize_t u, diff_opt_t *opts);
+static hsize_t character_compare_opt(unsigned char *mem1, unsigned char *mem2, hsize_t elemtno, diff_opt_t *opts);
 static hbool_t equal_float(float value, float expected, diff_opt_t *opts);
 static hbool_t equal_double(double value, double expected, diff_opt_t *opts);
 #if H5_SIZEOF_LONG_DOUBLE !=0
 static hbool_t equal_ldouble(long double value, long double expected, diff_opt_t *opts);
 #endif
+
 static int print_data(diff_opt_t *opts);
-static void print_pos(int *ph, int pp, hsize_t curr_pos, hsize_t *acc,
-        hsize_t *pos, int rank, hsize_t *dims, const char *obj1,
-        const char *obj2);
-static void print_char_pos(int *ph, int pp, hsize_t curr_pos, size_t u,
-        hsize_t *acc, hsize_t *pos, int rank, hsize_t *dims, const char *obj1,
-        const char *obj2);
+static void print_pos(diff_opt_t *opts, hsize_t elemtno, ssize_t u);
 static void h5diff_print_char(char ch);
-static hsize_t diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx,
-        int rank, hsize_t *dims, hsize_t *acc, hsize_t *pos,
-        diff_opt_t *opts, const char *obj1, const char *obj2,
-        hid_t container1_id, hid_t container2_id, /*where the reference came from*/
-        int *ph, /*print header */
-        mcomp_t *members); /*compound members */
-static hsize_t diff_float(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_double(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
+
+static hsize_t diff_region(hid_t obj1_id, hid_t obj2_id, hid_t region1_id, hid_t region2_id, diff_opt_t *opts);
+static hsize_t diff_datum(void *_mem1, void *_mem2, hsize_t elemtno, diff_opt_t *opts,
+        hid_t container1_id, hid_t container2_id, mcomp_t *members);
+/* element diffs */
+static hsize_t diff_float_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_double_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
 #if H5_SIZEOF_LONG_DOUBLE !=0
-static hsize_t diff_ldouble(unsigned char *mem1,
-        unsigned char *mem2,
-        hsize_t nelmts,
-        hsize_t hyper_start,
-        int rank,
-        hsize_t *dims,
-        hsize_t *acc,
-        hsize_t *pos,
-        diff_opt_t *opts,
-        const char *obj1,
-        const char *obj2,
-        int *ph);
+static hsize_t diff_ldouble_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
 #endif
-static hsize_t diff_schar(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_uchar(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_short(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_ushort(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_int(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_uint(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_long(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_ulong(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_llong(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
-static hsize_t diff_ullong(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph);
+static hsize_t diff_schar_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_uchar_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_short_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_ushort_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_int_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_uint_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_long_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_ulong_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_llong_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
+static hsize_t diff_ullong_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts);
 
 /*-------------------------------------------------------------------------
  * NaN detection
@@ -260,26 +202,23 @@ static void close_member_types(mcomp_t *members);
  *-------------------------------------------------------------------------
  */
 
-hsize_t diff_array(void *_mem1, void *_mem2, hsize_t nelmts, hsize_t hyper_start,
-        int rank, hsize_t *dims, diff_opt_t *opts, const char *name1, const char *name2,
-        hid_t m_type, hid_t container1_id, hid_t container2_id)
+hsize_t
+diff_array(void *_mem1, void *_mem2, diff_opt_t *opts, hid_t container1_id, hid_t container2_id)
 {
     hsize_t         nfound = 0; /* number of differences found */
     size_t          size; /* size of datum */
     unsigned char  *mem1 = (unsigned char*) _mem1;
     unsigned char  *mem2 = (unsigned char*) _mem2;
-    hsize_t         acc[32]; /* accumulator position */
-    hsize_t         pos[32]; /* matrix position */
-    int             ph = 1; /* print header  */
     hsize_t         i;
-    int             j;
     mcomp_t         members;
     H5T_class_t     type_class;
 
-    H5TOOLS_START_DEBUG(" - errstat:%d", opts->err_stat);
+    H5TOOLS_START_DEBUG(" - rank:%d hs_nelmts:%ld errstat:%d", opts->rank, opts->hs_nelmts, opts->err_stat);
+    opts->print_header = 1; /* enable print header  */
+
     /* get the size. */
-    size = H5Tget_size(m_type);
-    type_class = H5Tget_class(m_type);
+    size = H5Tget_size(opts->m_tid);
+    type_class = H5Tget_class(opts->m_tid);
 
     /* Fast comparison first for atomic type by memcmp().
      * It is OK not to list non-atomic type here because it will not be caught
@@ -289,24 +228,18 @@ hsize_t diff_array(void *_mem1, void *_mem2, hsize_t nelmts, hsize_t hyper_start
             type_class != H5T_COMPOUND &&
             type_class != H5T_STRING &&
             type_class != H5T_VLEN &&
-            HDmemcmp(mem1, mem2, size*nelmts) == 0)
+            HDmemcmp(mem1, mem2, size * opts->hs_nelmts) == 0) {
+        H5TOOLS_ENDDEBUG(":Fast comparison - errstat:%d", opts->err_stat);
         return 0;
-
-    if (rank > 0) {
-        acc[rank - 1] = 1;
-        for (j = (rank - 2); j >= 0; j--) {
-            acc[j] = acc[j + 1] * dims[j + 1];
-        }
-        for (j = 0; j < rank; j++)
-            pos[j] = 0;
     }
 
-    H5TOOLS_DEBUG("diff_array type_class:%d", type_class);
+    H5TOOLS_DEBUG("type_class:%d", type_class);
     switch (type_class) {
     case H5T_NO_CLASS:
     case H5T_TIME:
     case H5T_NCLASSES:
     default:
+        H5TOOLS_DEBUG("type_class:INVALID");
         HDassert(0);
         break;
 
@@ -315,37 +248,142 @@ hsize_t diff_array(void *_mem1, void *_mem2, hsize_t nelmts, hsize_t hyper_start
      *-------------------------------------------------------------------------
      */
     case H5T_FLOAT:
-        if (H5Tequal(m_type, H5T_NATIVE_FLOAT))
-            nfound = diff_float(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_DOUBLE))
-            nfound = diff_double(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
+        H5TOOLS_DEBUG("type_class:H5T_FLOAT");
+        if (H5Tequal(opts->m_tid, H5T_NATIVE_FLOAT)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_float_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(float);
+                mem2 += sizeof(float);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_DOUBLE)){
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_double_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(double);
+                mem2 += sizeof(double);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
 #if H5_SIZEOF_LONG_DOUBLE != 0
-        else if (H5Tequal(m_type, H5T_NATIVE_LDOUBLE))
-        nfound = diff_ldouble(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_LDOUBLE)) {
+            for ( i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_ldouble_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(long double);
+                mem2 += sizeof(long double);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
 #endif
         break;
 
     case H5T_INTEGER:
-        if (H5Tequal(m_type, H5T_NATIVE_SCHAR))
-            nfound = diff_schar(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_UCHAR))
-            nfound = diff_uchar(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_SHORT))
-            nfound = diff_short(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_USHORT))
-            nfound = diff_ushort(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_INT))
-            nfound = diff_int(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_UINT))
-            nfound = diff_uint(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_LONG))
-            nfound = diff_long(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_ULONG))
-            nfound = diff_ulong(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_LLONG))
-            nfound = diff_llong(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
-        else if (H5Tequal(m_type, H5T_NATIVE_ULLONG))
-            nfound = diff_ullong(mem1, mem2, nelmts, hyper_start, rank, dims, acc, pos, opts, name1, name2, &ph);
+        H5TOOLS_DEBUG("type_class:H5T_INTEGER");
+        if (H5Tequal(opts->m_tid, H5T_NATIVE_SCHAR)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_schar_element(mem1, mem2, i, opts);
+                mem1 += sizeof(char);
+                mem2 += sizeof(char);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_UCHAR)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_uchar_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(unsigned char);
+                mem2 += sizeof(unsigned char);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_SHORT)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_short_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(short);
+                mem2 += sizeof(short);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_USHORT)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_ushort_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(unsigned short);
+                mem2 += sizeof(unsigned short);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_INT)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_int_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(int);
+                mem2 += sizeof(int);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_UINT)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_int_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(unsigned int);
+                mem2 += sizeof(unsigned int);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_LONG)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_long_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(long);
+                mem2 += sizeof(long);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_ULONG)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_ulong_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(unsigned long);
+                mem2 += sizeof(unsigned long);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_LLONG)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_llong_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(long long);
+                mem2 += sizeof(long long);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
+        else if (H5Tequal(opts->m_tid, H5T_NATIVE_ULLONG)) {
+            for (i = 0; i < opts->hs_nelmts; i++) {
+                nfound += diff_ullong_element(mem1, mem2, i, opts);
+
+                mem1 += sizeof(unsigned long long);
+                mem2 += sizeof(unsigned long long);
+                if (opts->count_bool && nfound >= opts->count)
+                    return nfound;
+            } /* nelmts */
+        }
         break;
 
     /*-------------------------------------------------------------------------
@@ -360,13 +398,13 @@ hsize_t diff_array(void *_mem1, void *_mem2, hsize_t nelmts, hsize_t hyper_start
     case H5T_ARRAY:
     case H5T_VLEN:
     case H5T_REFERENCE:
+        H5TOOLS_DEBUG("type_class:OTHER");
         HDmemset(&members, 0, sizeof(mcomp_t));
-        get_member_types(m_type, &members);
-        H5TOOLS_DEBUG("call diff_datum nelmts:%d - errstat:%d", nelmts, opts->err_stat);
-        for (i = 0; i < nelmts; i++) {
-            nfound += diff_datum(mem1 + i * size, mem2 + i * size, m_type, i, rank, dims, acc, pos, opts,
-                    name1, name2, container1_id, container2_id, &ph, &members);
-            if (opts->n && nfound >= opts->count)
+        get_member_types(opts->m_tid, &members);
+        for (i = 0; i < opts->hs_nelmts; i++) {
+            H5TOOLS_DEBUG("opts->pos[%ld]:%ld - nelmts:%ld", i, opts->pos[i], opts->hs_nelmts);
+            nfound += diff_datum(mem1 + i * size, mem2 + i * size, i, opts, container1_id, container2_id, &members);
+            if (opts->count_bool && nfound >= opts->count)
                 break;
         } /* i */
         close_member_types(&members);
@@ -409,12 +447,7 @@ hsize_t diff_array(void *_mem1, void *_mem2, hsize_t nelmts, hsize_t hyper_start
  *-------------------------------------------------------------------------
  */
 static hsize_t
-diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
-    hsize_t *dims, hsize_t *acc, hsize_t *pos, diff_opt_t *opts,
-    const char *obj1, const char *obj2,
-    hid_t container1_id, hid_t container2_id,
-        int *ph,             /*print header */
-        mcomp_t *members)    /*compound members */
+diff_datum(void *_mem1, void *_mem2, hsize_t elemtno, diff_opt_t *opts, hid_t container1_id, hid_t container2_id, mcomp_t *members)
 {
     unsigned char  *mem1 = (unsigned char*) _mem1;
     unsigned char  *mem2 = (unsigned char*) _mem2;
@@ -425,7 +458,6 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
     size_t          offset;
     unsigned        nmembs;
     unsigned        j;
-    hsize_t         nelmts;
     size_t          size = 0;
     hbool_t         iszero1;
     hbool_t         iszero2;
@@ -434,10 +466,10 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
     hbool_t         both_zero;
     diff_err_t      ret_value = opts->err_stat;
 
-    H5TOOLS_START_DEBUG(" - errstat:%d", opts->err_stat);
+    H5TOOLS_START_DEBUG("ph:%d elemtno:%d - errstat:%d", opts->print_header, elemtno, opts->err_stat);
 
-    type_size = H5Tget_size(m_type);
-    type_class = H5Tget_class(m_type);
+    type_size = H5Tget_size(opts->m_tid);
+    type_class = H5Tget_class(opts->m_tid);
 
     /* Fast comparison first for atomic type by memcmp().
      * It is OK not to list non-atomic type here because it will not be caught
@@ -450,7 +482,7 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
             HDmemcmp(mem1, mem2, type_size) == 0)
         H5TOOLS_GOTO_DONE(opts->err_stat);
 
-    switch (H5Tget_class(m_type)) {
+    switch (H5Tget_class(opts->m_tid)) {
     case H5T_NO_CLASS:
     case H5T_TIME:
     case H5T_NCLASSES:
@@ -463,18 +495,22 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      *-------------------------------------------------------------------------
      */
     case H5T_COMPOUND:
-        H5TOOLS_DEBUG("diff_datum H5T_COMPOUND");
+        H5TOOLS_DEBUG("H5T_COMPOUND");
         {
-            hid_t memb_type = H5I_INVALID_HID;
+            diff_opt_t cmpd_opts;
+
+            cmpd_opts = *opts;
             nmembs = members->n;
 
             for (j = 0; j < nmembs; j++) {
                 offset = members->offsets[j];
-                memb_type = members->ids[j];
+                cmpd_opts.m_tid = members->ids[j];
 
-                nfound += diff_datum(mem1 + offset, mem2 + offset, memb_type, idx,
-                        rank, dims, acc, pos, opts, obj1, obj2, container1_id, container2_id, ph, members->m[j]);
+                nfound += diff_datum(mem1 + offset, mem2 + offset, elemtno, &cmpd_opts, container1_id, container2_id, members->m[j]);
             }
+            opts->err_stat =  opts->err_stat | cmpd_opts.err_stat;
+            opts->print_header = cmpd_opts.print_header;
+            opts->not_cmp = cmpd_opts.not_cmp;
         }
         break;
 
@@ -483,7 +519,7 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      *-------------------------------------------------------------------------
      */
     case H5T_STRING:
-        H5TOOLS_DEBUG("diff_datum H5T_STRING");
+        H5TOOLS_DEBUG("H5T_STRING");
         {
             char *s = NULL;
             char *sx = NULL;
@@ -492,12 +528,12 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
             size_t size1;
             size_t size2;
             size_t sizex;
-            size_t size_mtype = H5Tget_size(m_type);
-            H5T_str_t pad = H5Tget_strpad(m_type);
+            size_t size_mtype = H5Tget_size(opts->m_tid);
+            H5T_str_t pad = H5Tget_strpad(opts->m_tid);
 
             /* if variable length string */
-            if (H5Tis_variable_str(m_type)) {
-                H5TOOLS_DEBUG("diff_datum H5T_STRING variable");
+            if (H5Tis_variable_str(opts->m_tid)) {
+                H5TOOLS_DEBUG("H5T_STRING variable");
                 /* Get pointer to first string */
                 s1 = *(char **)((void *)mem1);
                 if (s1)
@@ -513,7 +549,7 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
                     size2 = 0;
             }
             else if (H5T_STR_NULLTERM == pad) {
-                H5TOOLS_DEBUG("diff_datum H5T_STRING null term");
+                H5TOOLS_DEBUG("H5T_STRING null term");
                 /* Get pointer to first string */
                 s1 = (char*) mem1;
                 if (s1)
@@ -550,10 +586,10 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
              *       of length of strings.
              *       For now mimic the previous way.
              */
-            H5TOOLS_DEBUG("diff_datum string size:%d", size1);
-            H5TOOLS_DEBUG("diff_datum string size:%d", size2);
+            H5TOOLS_DEBUG("string size:%d", size1);
+            H5TOOLS_DEBUG("string size:%d", size2);
             if (size1 != size2) {
-                H5TOOLS_DEBUG("diff_datum string sizes difference");
+                H5TOOLS_DEBUG("string sizes difference");
                 nfound++;
             }
             if (size1 < size2) {
@@ -572,15 +608,13 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
             /* check for NULL pointer for string */
             if (s != NULL) {
                 /* try fast compare first */
-                if (HDmemcmp(s, sx, size) == 0) {
-                    if (size1 != size2)
-                        if (print_data(opts))
-                            for (u = size; u < sizex; u++)
-                                character_compare(s + u, sx + u, idx, u, rank, dims, acc, pos, opts, obj1, obj2, ph);
+                if ((HDmemcmp(s, sx, size) == 0) && (size1 != size2)) {
+                    for (u = size; u < sizex; u++)
+                        character_compare(s + u, sx + u, elemtno, u, opts);
                 }
                 else
                     for (u = 0; u < size; u++)
-                        nfound += character_compare(s + u, sx + u, idx, u, rank, dims, acc, pos, opts, obj1, obj2, ph);
+                        nfound += character_compare(s + u, sx + u, elemtno, u, opts);
             } /* end check for NULL pointer for string */
         }
         break;
@@ -590,10 +624,10 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      *-------------------------------------------------------------------------
      */
     case H5T_BITFIELD:
-        H5TOOLS_DEBUG("diff_datum H5T_BITFIELD");
+        H5TOOLS_DEBUG("H5T_BITFIELD");
         /* byte-by-byte comparison */
         for (u = 0; u < type_size; u++)
-            nfound += character_compare_opt(mem1 + u, mem2 + u, idx, rank, dims, acc, pos, opts, obj1, obj2, ph);
+            nfound += character_compare_opt(mem1 + u, mem2 + u, elemtno, opts);
         break;
 
     /*-------------------------------------------------------------------------
@@ -601,10 +635,10 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      *-------------------------------------------------------------------------
      */
     case H5T_OPAQUE:
-        H5TOOLS_DEBUG("diff_datum H5T_OPAQUE");
+        H5TOOLS_DEBUG("H5T_OPAQUE");
         /* byte-by-byte comparison */
         for (u = 0; u < type_size; u++)
-            nfound += character_compare_opt(mem1 + u, mem2 + u, idx, rank, dims, acc, pos, opts, obj1, obj2, ph);
+            nfound += character_compare_opt(mem1 + u, mem2 + u, elemtno, opts);
         break;
 
     /*-------------------------------------------------------------------------
@@ -617,7 +651,7 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          * compared, we convert both bit patterns to their corresponding
          * enumeration constant and do a string comparison
          */
-        H5TOOLS_DEBUG("diff_datum H5T_ENUM");
+        H5TOOLS_DEBUG("H5T_ENUM");
         {
             char enum_name1[1024];
             char enum_name2[1024];
@@ -629,11 +663,11 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
                 /* If the enum value cannot be converted to a string
                  * it is set to an error string for later output.
                  */
-                err1 = H5Tenum_nameof(m_type, mem1, enum_name1, sizeof enum_name1);
+                err1 = H5Tenum_nameof(opts->m_tid, mem1, enum_name1, sizeof enum_name1);
                 if (err1 < 0)
                     HDsnprintf(enum_name1, sizeof(enum_name1), "**INVALID VALUE**");
 
-                err2 = H5Tenum_nameof(m_type, mem2, enum_name2, sizeof enum_name2);
+                err2 = H5Tenum_nameof(opts->m_tid, mem2, enum_name2, sizeof enum_name2);
                 if (err2 < 0)
                     HDsnprintf(enum_name2, sizeof(enum_name2), "**INVALID VALUE**");
 
@@ -644,9 +678,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
                      * don't attempt to convert them - just report errors.
                      */
                     nfound += 1;
+                    opts->print_percentage = 0;
+                    print_pos(opts, elemtno, -1);
                     if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
                         parallel_print(S_FORMAT, enum_name1, enum_name2);
                     }
                 }
@@ -654,15 +688,15 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
                     /* Both enum values were valid */
                     if (HDstrcmp(enum_name1, enum_name2) != 0) {
                         nfound = 1;
+                        opts->print_percentage = 0;
+                        print_pos(opts, elemtno, -1);
                         if (print_data(opts)) {
-                            print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
                             parallel_print(S_FORMAT, enum_name1, enum_name2);
                         }
                     }
                     else {
                         for (u = 0; u < type_size; u++)
-                            nfound += character_compare_opt(mem1 + u, mem2 + u, idx, rank, dims, acc, pos, opts, obj1, obj2, ph);
+                            nfound += character_compare_opt(mem1 + u, mem2 + u, elemtno, opts);
                     }
                 }
                 /* enable error reporting */
@@ -676,26 +710,32 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      */
     case H5T_ARRAY:
         {
-            hid_t   memb_type = H5I_INVALID_HID;
             hsize_t adims[H5S_MAX_RANK];
             int     ndims;
+            diff_opt_t arr_opts;
+
+            H5TOOLS_DEBUG("H5T_ARRAY ph=%d", opts->print_header);
 
-            H5TOOLS_DEBUG("diff_datum H5T_ARRAY");
+            arr_opts = *opts;
+            H5TOOLS_DEBUG("Check opts: hs_nelmts:%ld to %ld rank:%d to %ld", opts->hs_nelmts, arr_opts.hs_nelmts, opts->rank, arr_opts.rank);
             /* get the array's base datatype for each element */
-            memb_type = H5Tget_super(m_type);
-            size = H5Tget_size(memb_type);
-            ndims = H5Tget_array_ndims(m_type);
-            H5Tget_array_dims2(m_type, adims);
+            arr_opts.m_tid = H5Tget_super(opts->m_tid);
+            size = H5Tget_size(arr_opts.m_tid);
+            ndims = H5Tget_array_ndims(opts->m_tid);
+            H5Tget_array_dims2(opts->m_tid, adims);
             HDassert(ndims >= 1 && ndims <= H5S_MAX_RANK);
+            H5TOOLS_DEBUG("attr ph=%d", arr_opts.print_header);
 
             /* calculate the number of array elements */
-            for (u = 0, nelmts = 1; u < (unsigned) ndims; u++)
-                nelmts *= adims[u];
-            for (u = 0; u < nelmts; u++) {
-                nfound += diff_datum(mem1 + u * size, mem2 + u * size, memb_type, idx,
-                        rank, dims, acc, pos, opts, obj1, obj2, container1_id, container2_id, ph, members);
-            }
-            H5Tclose(memb_type);
+            for (u = 0, arr_opts.hs_nelmts = 1; u < (unsigned) ndims; u++)
+                arr_opts.hs_nelmts *= adims[u];
+            for (u = 0; u < arr_opts.hs_nelmts; u++) {
+                nfound += diff_datum(mem1 + u * size, mem2 + u * size, elemtno, &arr_opts, container1_id, container2_id, members);
+            }
+            opts->err_stat =  opts->err_stat | arr_opts.err_stat;
+            opts->print_header = arr_opts.print_header;
+            opts->not_cmp = arr_opts.not_cmp;
+            H5Tclose(arr_opts.m_tid);
         }
         break;
 
@@ -704,9 +744,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      *-------------------------------------------------------------------------
      */
     case H5T_REFERENCE:
-        H5TOOLS_DEBUG("diff_datum H5T_REFERENCE");
-        iszero1 = all_zero(_mem1, H5Tget_size(m_type));
-        iszero2 = all_zero(_mem2, H5Tget_size(m_type));
+        H5TOOLS_DEBUG("H5T_REFERENCE");
+        iszero1 = all_zero(_mem1, H5Tget_size(opts->m_tid));
+        iszero2 = all_zero(_mem2, H5Tget_size(opts->m_tid));
         if (iszero1 != iszero2) {
             nfound++;
             H5TOOLS_GOTO_DONE(opts->err_stat);
@@ -714,93 +754,114 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
         else if (!iszero1 && !iszero2) {
             hid_t obj1_id = H5I_INVALID_HID;
             hid_t obj2_id = H5I_INVALID_HID;
+            diff_opt_t ref_opts;
 
-            /*-------------------------------------------------------------------------
-             * H5T_STD_REF_DSETREG
-             * Dataset region reference
-             *-------------------------------------------------------------------------
-             */
-            if (type_size == H5R_DSET_REG_REF_BUF_SIZE) {
-                hid_t region1_id = H5I_INVALID_HID;
-                hid_t region2_id = H5I_INVALID_HID;
-
-                H5TOOLS_INFO("H5T_STD_REF_DSETREG reference type");
-
-                if ((obj1_id = H5Rdereference2(container1_id, H5P_DEFAULT, H5R_DATASET_REGION, _mem1)) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rdereference2 object 1 failed");
-                }
-                if ((obj2_id = H5Rdereference2(container2_id, H5P_DEFAULT, H5R_DATASET_REGION, _mem2)) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rdereference2 object 2 failed");
-                }
-                if ((region1_id = H5Rget_region(container1_id, H5R_DATASET_REGION, _mem1)) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rget_region object 1 failed");
-                }
-                if ((region2_id = H5Rget_region(container2_id, H5R_DATASET_REGION, _mem2)) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rget_region object 2 failed");
-                }
-
-                nfound = diff_region(obj1_id, obj2_id, region1_id, region2_id, opts);
-
-                H5Oclose(obj1_id);
-                H5Oclose(obj2_id);
-                H5Sclose(region1_id);
-                H5Sclose(region2_id);
-            }/*dataset reference*/
+            ref_opts = *opts;
+            ref_opts.obj_name[0] = NULL;
+            ref_opts.obj_name[1] = NULL;
 
             /*-------------------------------------------------------------------------
              * H5T_STD_REF_OBJ
              * Object references. get the type and OID of the referenced object
              *-------------------------------------------------------------------------
              */
-            else if (type_size == H5R_OBJ_REF_BUF_SIZE) {
+            if (type_size == H5R_OBJ_REF_BUF_SIZE) {
                 H5O_type_t obj1_type;
                 H5O_type_t obj2_type;
 
-                H5TOOLS_INFO("H5T_STD_REF_OBJ reference type");
+                H5TOOLS_DEBUG("ref_type is H5T_STD_REF_OBJ");
+
+                if (H5Rget_obj_type2(container1_id, H5R_OBJECT, _mem1, &obj1_type) >= 0) {
+                    if (H5Rget_obj_type2(container2_id, H5R_OBJECT, _mem2, &obj2_type) >= 0) {
+                        /* check object type */
+                        if (obj1_type == obj2_type) {
+                            if (obj1_type == H5O_TYPE_DATASET) {
+                                if ((obj1_id = H5Rdereference2(container1_id, H5P_DEFAULT, H5R_OBJECT, _mem1)) >= 0) {
+                                    if ((obj2_id = H5Rdereference2(container2_id, H5P_DEFAULT, H5R_OBJECT, _mem2)) >= 0) {
+                                        /* compare */
+                                        nfound = diff_datasetid(obj1_id, obj2_id, opts->obj_name[0], opts->obj_name[1], &ref_opts);
+                                        if(H5Oclose(obj2_id) < 0) {
+                                            ref_opts.err_stat = H5DIFF_ERR;
+                                            H5TOOLS_INFO("H5Oclose H5T_STD_REF_OBJ 2 failed");
+                                        }
+                                    }
+                                    else {
+                                        ref_opts.err_stat = H5DIFF_ERR;
+                                        H5TOOLS_INFO("H5Rdereference2 object 2 failed");
+                                    }
+                                    if(H5Oclose(obj1_id) < 0) {
+                                        ref_opts.err_stat = H5DIFF_ERR;
+                                        H5TOOLS_INFO("H5Oclose H5T_STD_REF_OBJ 1 failed");
+                                    }
+                                }
+                                else {
+                                    ref_opts.err_stat = H5DIFF_ERR;
+                                    H5TOOLS_INFO("H5Rdereference2 object 1 failed");
+                                }
+                            }
+                            else {
+                                if (ref_opts.mode_verbose)
+                                    parallel_print("Warning: Comparison not possible of object types referenced: <%s> and <%s>\n", obj1_type, obj2_type);
+                                ref_opts.not_cmp = 1;
+                            }
+                       }
+                       else {
+                           parallel_print("Different object types referenced: <%s> and <%s>", opts->obj_name[0], opts->obj_name[1]);
+                           ref_opts.not_cmp = 1;
+                           ref_opts.err_stat = H5DIFF_ERR;
+                       }
+                   }
+                   else {
+                       ref_opts.err_stat = H5DIFF_ERR;
+                       H5TOOLS_INFO("H5Rget_obj_type2 object 2 failed");
+                   }
+               }
+               else {
+                   ref_opts.err_stat = H5DIFF_ERR;
+                   H5TOOLS_INFO("H5Rget_obj_type2 object 1 failed");
+               }
+            }/*object reference*/
 
-                if (H5Rget_obj_type2(container1_id, H5R_OBJECT, _mem1, &obj1_type) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rget_obj_type2 object 1 failed");
-                }
-                if (H5Rget_obj_type2(container2_id, H5R_OBJECT, _mem2, &obj2_type) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rget_obj_type2 object 2 failed");
-                }
+            /*-------------------------------------------------------------------------
+             * H5T_STD_REF_DSETREG
+             * Dataset region reference
+             *-------------------------------------------------------------------------
+             */
+            else if (type_size == H5R_DSET_REG_REF_BUF_SIZE) {
+                hid_t region1_id = H5I_INVALID_HID;
+                hid_t region2_id = H5I_INVALID_HID;
 
-                /* check object type */
-                if (obj1_type != obj2_type) {
-                    parallel_print("Different object types referenced: <%s> and <%s>", obj1, obj2);
-                    opts->not_cmp = 1;
-                    H5TOOLS_GOTO_DONE(opts->err_stat);
-                }
+                H5TOOLS_DEBUG("H5T_REFERENCE - H5T_STD_REF_DSETREG");
 
-                if ((obj1_id = H5Rdereference2(container1_id, H5P_DEFAULT, H5R_OBJECT, _mem1)) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rdereference2 object 1 failed");
-                }
-                if ((obj2_id = H5Rdereference2(container2_id, H5P_DEFAULT, H5R_OBJECT, _mem2)) < 0) {
-                    opts->err_stat = H5DIFF_ERR;
-                    H5TOOLS_INFO("H5Rdereference2 object 2 failed");
+                if ((obj1_id = H5Rdereference2(container1_id, H5P_DEFAULT, H5R_DATASET_REGION, _mem1)) >= 0) {
+                    if ((obj2_id = H5Rdereference2(container2_id, H5P_DEFAULT, H5R_DATASET_REGION, _mem2)) >= 0) {
+                        if ((region1_id = H5Rget_region(container1_id, H5R_DATASET_REGION, _mem1)) >= 0) {
+                            if ((region2_id = H5Rget_region(container2_id, H5R_DATASET_REGION, _mem2)) >= 0) {
+                                nfound = diff_region(obj1_id, obj2_id, region1_id, region2_id, &ref_opts);
+                                if(H5Sclose(region2_id) < 0)
+                                    H5TOOLS_INFO("H5Sclose H5T_STD_REF_DSETREG region 2 failed");
+                            }
+                            if(H5Sclose(region1_id) < 0)
+                                H5TOOLS_INFO("H5Sclose H5T_STD_REF_DSETREG region 1 failed");
+                        }
+                        if(H5Oclose(obj2_id) < 0)
+                            H5TOOLS_INFO("H5Oclose H5T_STD_REF_DSETREG region 2 failed");
+                    }
+                    else {
+                        H5TOOLS_INFO("H5Rdereference2 object 2 failed");
+                    }
+                    if(H5Oclose(obj1_id) < 0)
+                        H5TOOLS_INFO("H5Oclose H5T_STD_REF_DSETREG region 1 failed");
                 }
-
-                /* compare */
-                if (obj1_type == H5O_TYPE_DATASET)
-                    nfound = diff_datasetid(obj1_id, obj2_id, NULL, NULL, opts);
                 else {
-                    if (opts->m_verbose)
-                        parallel_print("Warning: Comparison not possible of object types referenced: <%s> and <%s>\n", obj1, obj2);
-                    opts->not_cmp = 1;
+                    H5TOOLS_INFO("H5Rdereference2 object 1 failed");
                 }
-
-                H5Oclose(obj1_id);
-                H5Oclose(obj2_id);
-            }/*object reference*/
+            }/*dataset reference*/
+            opts->print_header = ref_opts.print_header;
+            opts->not_cmp = ref_opts.not_cmp;
+            opts->err_stat = ref_opts.err_stat | ret_value;
         }/*is zero*/
-        H5TOOLS_DEBUG("diff_datum H5T_REFERENCE complete");
+        H5TOOLS_DEBUG("H5T_REFERENCE complete");
         break;
 
     /*-------------------------------------------------------------------------
@@ -809,21 +870,26 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      */
     case H5T_VLEN:
         {
-            hid_t memb_type = H5I_INVALID_HID;
+            diff_opt_t vl_opts;
 
-            H5TOOLS_DEBUG("diff_datum H5T_VLEN");
+            H5TOOLS_DEBUG("H5T_VLEN");
+
+            vl_opts = *opts;
             /* get the VL sequences's base datatype for each element */
-            memb_type = H5Tget_super(m_type);
-            size = H5Tget_size(memb_type);
+            vl_opts.m_tid = H5Tget_super(opts->m_tid);
+            size = H5Tget_size(vl_opts.m_tid);
 
             /* get the number of sequence elements */
-            nelmts = ((hvl_t *)((void *)mem1))->len;
+            vl_opts.hs_nelmts = ((hvl_t *)((void *)mem1))->len;
 
-            for (j = 0; j < nelmts; j++)
-                nfound += diff_datum(((char *) (((hvl_t *)((void *)mem1))->p)) + j * size, ((char *) (((hvl_t *)((void *)mem2))->p)) + j * size, memb_type, idx,      /* Extra (void *) cast to quiet "cast to create alignment" warning - 2019/07/05, QAK */
-                        rank, dims, acc, pos, opts, obj1, obj2, container1_id, container2_id, ph, members);
+            for (j = 0; j < vl_opts.hs_nelmts; j++)
+                nfound += diff_datum(((char *) (((hvl_t *)((void *)mem1))->p)) + j * size, ((char *) (((hvl_t *)((void *)mem2))->p)) + j * size, elemtno,      /* Extra (void *) cast to quiet "cast to create alignment" warning - 2019/07/05, QAK */
+                        &vl_opts, container1_id, container2_id, members);
+            opts->print_header = vl_opts.print_header;
+            opts->not_cmp = vl_opts.not_cmp;
+            opts->err_stat =  opts->err_stat | vl_opts.err_stat;
 
-            H5Tclose(memb_type);
+            H5Tclose(vl_opts.m_tid);
         }
         break;
 
@@ -832,81 +898,16 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
      *-------------------------------------------------------------------------
      */
     case H5T_INTEGER:
-        H5TOOLS_DEBUG("diff_datum H5T_INTEGER");
-        type_sign = H5Tget_sign(m_type);
+        H5TOOLS_DEBUG("H5T_INTEGER");
+        type_sign = H5Tget_sign(opts->m_tid);
         /*-------------------------------------------------------------------------
          * H5T_NATIVE_SCHAR
          *-------------------------------------------------------------------------
          */
         if (type_size == 1 && type_sign != H5T_SGN_NONE) {
-            char temp1_char;
-            char temp2_char;
-
             if(type_size != sizeof(char))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not char size");
-            HDmemcpy(&temp1_char, mem1, sizeof(char));
-            HDmemcpy(&temp2_char, mem2, sizeof(char));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (ABS(temp1_char-temp2_char) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER(temp1_char, temp2_char);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_char, temp2_char, ABS(temp1_char - temp2_char), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER(temp1_char, temp2_char);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && ABS(temp1_char - temp2_char) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_char, temp2_char, ABS(temp1_char - temp2_char), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_char != temp2_char) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                }
-                nfound++;
-            }
+            nfound += diff_schar_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_SCHAR*/
 
         /*-------------------------------------------------------------------------
@@ -914,75 +915,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == 1 && type_sign == H5T_SGN_NONE) {
-            unsigned char temp1_uchar;
-            unsigned char temp2_uchar;
-
             if(type_size != sizeof(unsigned char))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not unsigned char size");
-
-            HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
-            HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (PDIFF(temp1_uchar, temp2_uchar) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && PDIFF(temp1_uchar, temp2_uchar) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_uchar != temp2_uchar) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                }
-                nfound++;
-            }
+            nfound += diff_uchar_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_UCHAR*/
 
         /*-------------------------------------------------------------------------
@@ -990,75 +925,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == 2 && type_sign != H5T_SGN_NONE) {
-            short temp1_short;
-            short temp2_short;
-
             if(type_size != sizeof(short))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not short size");
-
-            HDmemcpy(&temp1_short, mem1, sizeof(short));
-            HDmemcpy(&temp2_short, mem2, sizeof(short));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (ABS(temp1_short - temp2_short) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER(temp1_short, temp2_short);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_short, temp2_short, ABS(temp1_short - temp2_short), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER(temp1_short, temp2_short);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && ABS(temp1_short - temp2_short) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_short, temp2_short, ABS(temp1_short - temp2_short), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_short != temp2_short) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                }
-                nfound++;
-            }
+            nfound += diff_short_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_SHORT*/
 
         /*-------------------------------------------------------------------------
@@ -1066,75 +935,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == 2 && type_sign == H5T_SGN_NONE) {
-            unsigned short temp1_ushort;
-            unsigned short temp2_ushort;
-
             if(type_size != sizeof(unsigned short))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not unsigned short size");
-
-            HDmemcpy(&temp1_ushort, mem1, sizeof(unsigned short));
-            HDmemcpy(&temp2_ushort, mem2, sizeof(unsigned short));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (PDIFF(temp1_ushort, temp2_ushort) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER_UNSIGN(signed short, temp1_ushort, temp2_ushort);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER_UNSIGN(signed short, temp1_ushort, temp2_ushort);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && PDIFF(temp1_ushort, temp2_ushort) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_ushort != temp2_ushort) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                }
-                nfound++;
-            }
+            nfound += diff_ushort_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_USHORT*/
 
         /*-------------------------------------------------------------------------
@@ -1142,75 +945,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == 4 && type_sign != H5T_SGN_NONE) {
-            int temp1_int;
-            int temp2_int;
-
             if(type_size != sizeof(int))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not int size");
-
-            HDmemcpy(&temp1_int, mem1, sizeof(int));
-            HDmemcpy(&temp2_int, mem2, sizeof(int));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (ABS(temp1_int-temp2_int) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER(temp1_int, temp2_int);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_int, temp2_int, ABS(temp1_int - temp2_int), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER(temp1_int, temp2_int);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P_NOTCOMP, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && ABS(temp1_int - temp2_int) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(I_FORMAT_P, temp1_int, temp2_int, ABS(temp1_int - temp2_int), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_int != temp2_int) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                }
-                nfound++;
-            }
+            nfound += diff_int_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_INT*/
 
         /*-------------------------------------------------------------------------
@@ -1218,75 +955,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == 4 && type_sign == H5T_SGN_NONE) {
-            unsigned int temp1_uint;
-            unsigned int temp2_uint;
-
             if(type_size != sizeof(unsigned int))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not unsigned int size");
-
-            HDmemcpy(&temp1_uint, mem1, sizeof(unsigned int));
-            HDmemcpy(&temp2_uint, mem2, sizeof(unsigned int));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (PDIFF(temp1_uint, temp2_uint) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(UI_FORMAT, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER_UNSIGN(signed int, temp1_uint, temp2_uint);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(UI_FORMAT_P_NOTCOMP, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(UI_FORMAT_P, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER_UNSIGN(signed int, temp1_uint, temp2_uint);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(UI_FORMAT_P_NOTCOMP, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && PDIFF(temp1_uint,temp2_uint) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(UI_FORMAT_P, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_uint != temp2_uint) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(UI_FORMAT, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                }
-                nfound++;
-            }
+            nfound += diff_uint_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_UINT*/
 
         /*-------------------------------------------------------------------------
@@ -1294,75 +965,9 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == 8 && type_sign != H5T_SGN_NONE) {
-            long temp1_long;
-            long temp2_long;
-
             if(type_size != sizeof(long))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not long size");
-
-            HDmemcpy(&temp1_long, mem1, sizeof(long));
-            HDmemcpy(&temp2_long, mem2, sizeof(long));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (ABS(temp1_long-temp2_long) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(LI_FORMAT, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER(temp1_long, temp2_long);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(LI_FORMAT_P_NOTCOMP, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(LI_FORMAT_P, temp1_long, temp2_long, ABS(temp1_long - temp2_long), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER(temp1_long, temp2_long);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(LI_FORMAT_P_NOTCOMP, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && ABS(temp1_long-temp2_long) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(LI_FORMAT_P, temp1_long, temp2_long, ABS(temp1_long - temp2_long), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_long != temp2_long) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                }
-                nfound++;
-            }
+            nfound += diff_long_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_LONG*/
 
         /*-------------------------------------------------------------------------
@@ -1370,76 +975,30 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == 8 && type_sign == H5T_SGN_NONE) {
-            unsigned long temp1_ulong;
-            unsigned long temp2_ulong;
-
             if(type_size != sizeof(unsigned long))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not unsigned long size");
+            nfound += diff_ulong_element(mem1, mem2, elemtno, opts);
+        } /*H5T_NATIVE_ULONG*/
 
-            HDmemcpy(&temp1_ulong, mem1, sizeof(unsigned long));
-            HDmemcpy(&temp2_ulong, mem2, sizeof(unsigned long));
-            /* -d and !-p */
-            if (opts->d && !opts->p) {
-                if (PDIFF(temp1_ulong, temp2_ulong) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(ULI_FORMAT, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                    }
-                    nfound++;
-                }
-            }
-            /* !-d and -p */
-            else if (!opts->d && opts->p) {
-                PER_UNSIGN(signed long, temp1_ulong, temp2_ulong);
-
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(ULI_FORMAT_P_NOTCOMP, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(ULI_FORMAT_P, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong), per);
-                    }
-                    nfound++;
-                }
-            }
-            /* -d and -p */
-            else if (opts->d && opts->p) {
-                PER_UNSIGN(signed long, temp1_ulong, temp2_ulong);
+        /*-------------------------------------------------------------------------
+         * H5T_NATIVE_LLONG
+         *-------------------------------------------------------------------------
+         */
+        else if (type_size == 16 && type_sign != H5T_SGN_NONE) {
+            if(type_size != sizeof(long long))
+                H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not long long size");
+            nfound += diff_llong_element(mem1, mem2, elemtno, opts);
+        } /*H5T_NATIVE_LLONG*/
 
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(ULI_FORMAT_P_NOTCOMP, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && PDIFF(temp1_ulong,temp2_ulong) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(ULI_FORMAT_P, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong), per);
-                    }
-                    nfound++;
-                }
-            }
-            else if (temp1_ulong != temp2_ulong) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULI_FORMAT, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                }
-                nfound++;
-            }
-        } /*H5T_NATIVE_ULONG*/
+        /*-------------------------------------------------------------------------
+         * H5T_NATIVE_ULLONG
+         *-------------------------------------------------------------------------
+         */
+        else if (type_size == 16 && type_sign == H5T_SGN_NONE) {
+            if(type_size != sizeof(unsigned long long))
+                H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not unsigned long long size");
+            nfound += diff_ullong_element(mem1, mem2, elemtno, opts);
+        } /*H5T_NATIVE_ULLONG*/
         break; /* H5T_INTEGER class */
 
     /*-------------------------------------------------------------------------
@@ -1451,319 +1010,21 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          * H5T_NATIVE_FLOAT
          *-------------------------------------------------------------------------
          */
-        H5TOOLS_DEBUG("diff_datum H5T_FLOAT");
+        H5TOOLS_DEBUG("H5T_FLOAT");
         if (type_size == 4) {
-            float temp1_float;
-            float temp2_float;
-            hbool_t isnan1 = FALSE;
-            hbool_t isnan2 = FALSE;
-
             if(type_size != sizeof(float))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not float size");
-
-            HDmemcpy(&temp1_float, mem1, sizeof(float));
-            HDmemcpy(&temp2_float, mem2, sizeof(float));
-
-            /* logic for detecting NaNs is different with opts -d, -p and no opts */
-
-            /*-------------------------------------------------------------------------
-             * -d and !-p
-             *-------------------------------------------------------------------------
-             */
-            if (opts->d && !opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_float);
-                    isnan2 = HDisnan(temp2_float);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    if (ABS(temp1_float-temp2_float) > (float) opts->delta) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                        }
-                        nfound++;
-                    }
-                }
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * !-d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (!opts->d && opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_float);
-                    isnan2 = HDisnan(temp2_float);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    PER(temp1_float, temp2_float);
-
-                    if (not_comparable && !both_zero) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P_NOTCOMP, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                        }
-                        nfound++;
-                    }
-                    else if (per > opts->percent && (double) ABS(temp1_float - temp2_float) > opts->delta) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P, (double) temp1_float, (double) temp2_float,
-                                    (double) ABS(temp1_float - temp2_float), (double) ABS(1 - temp2_float / temp1_float));
-                        }
-                        nfound++;
-                    }
-                }
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * -d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (opts->d && opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_float);
-                    isnan2 = HDisnan(temp2_float);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    PER(temp1_float, temp2_float);
-
-                    if (not_comparable && !both_zero) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P_NOTCOMP, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                        }
-                        nfound++;
-                    }
-                    else if (per > opts->percent) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P, (double) temp1_float, (double) temp2_float,
-                                    (double) ABS(temp1_float - temp2_float), (double) ABS(1 - temp2_float / temp1_float));
-                        }
-                        nfound++;
-                    }
-                }
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * no -d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (equal_float(temp1_float, temp2_float, opts) == FALSE) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                }
-                nfound++;
-            }
-        } /*H5T_NATIVE_FLOAT*/
-
+            nfound += diff_float_element(mem1, mem2, elemtno, opts);
+        }
         /*-------------------------------------------------------------------------
          * H5T_NATIVE_DOUBLE
          *-------------------------------------------------------------------------
          */
         else if (type_size == 8) {
-            double temp1_double;
-            double temp2_double;
-            hbool_t isnan1 = FALSE;
-            hbool_t isnan2 = FALSE;
-
             if(type_size != sizeof(double))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not double size");
-
-            HDmemcpy(&temp1_double, mem1, sizeof(double));
-            HDmemcpy(&temp2_double, mem2, sizeof(double));
-
-            /* logic for detecting NaNs is different with opts -d, -p and no opts */
-            /*-------------------------------------------------------------------------
-             * -d and !-p
-             *-------------------------------------------------------------------------
-             */
-            if (opts->d && !opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_double);
-                    isnan2 = HDisnan(temp2_double);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    if (ABS(temp1_double-temp2_double) > opts->delta) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                        }
-                        nfound++;
-                    }
-                }
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            } /* opts->d && !opts->p */
-            /*-------------------------------------------------------------------------
-             * !-d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (!opts->d && opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_double);
-                    isnan2 = HDisnan(temp2_double);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    PER(temp1_double, temp2_double);
-
-                    if (not_comparable && !both_zero) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                        }
-                        nfound++;
-                    }
-                    else if (per > opts->percent) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P, temp1_double, temp2_double, ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
-                        }
-                        nfound++;
-                    }
-                }
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * -d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (opts->d && opts->p) {
-                /*-------------------------------------------------------------------------
-                * detect NaNs
-                *-------------------------------------------------------------------------
-                */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_double);
-                    isnan2 = HDisnan(temp2_double);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    PER(temp1_double, temp2_double);
-
-                    if (not_comparable && !both_zero) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                        }
-                        nfound++;
-                    }
-                    else if (per > opts->percent &&
-                    ABS(temp1_double-temp2_double) > opts->delta) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(F_FORMAT_P, temp1_double, temp2_double, ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
-                        }
-                        nfound++;
-                    }
-                }
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * no -d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (equal_double(temp1_double, temp2_double, opts) == FALSE) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                }
-                nfound++;
-            }
-        } /*H5T_NATIVE_DOUBLE*/
-
+            nfound += diff_double_element(mem1, mem2, elemtno, opts);
+        }
 #if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
 
         /*-------------------------------------------------------------------------
@@ -1771,157 +1032,10 @@ diff_datum(void *_mem1, void *_mem2, hid_t m_type, hsize_t idx, int rank,
          *-------------------------------------------------------------------------
          */
         else if (type_size == H5_SIZEOF_LONG_DOUBLE) {
-            long double temp1_double;
-            long double temp2_double;
-            hbool_t     isnan1 = FALSE;
-            hbool_t     isnan2 = FALSE;
-
             if(type_size != sizeof(long double)) {
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Type size is not long double size");
             }
-
-            HDmemcpy(&temp1_double, mem1, sizeof(long double));
-            HDmemcpy(&temp2_double, mem2, sizeof(long double));
-
-            /* logic for detecting NaNs is different with options -d, -p and no options */
-
-            /*-------------------------------------------------------------------------
-             * -d and !-p
-             *-------------------------------------------------------------------------
-             */
-            if (opts->d && !opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_double);
-                    isnan2 = HDisnan(temp2_double);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    if (ABS(temp1_double-temp2_double) > opts->delta) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(LD_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                        }
-                        nfound++;
-                    }
-                } /* NaN */
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * !-d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (!opts->d && opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_double);
-                    isnan2 = HDisnan(temp2_double);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    PER(temp1_double,temp2_double);
-
-                    if (not_comparable && !both_zero) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(LD_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                        }
-                        nfound++;
-                    }
-                    else if (per > opts->percent) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(LD_FORMAT_P, temp1_double, temp2_double, ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
-                        }
-                        nfound++;
-                    }
-                } /* NaN */
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * -d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (opts->d && opts->p) {
-                /*-------------------------------------------------------------------------
-                 * detect NaNs
-                 *-------------------------------------------------------------------------
-                 */
-                if (opts->do_nans) {
-                    isnan1 = HDisnan(temp1_double);
-                    isnan2 = HDisnan(temp2_double);
-                }
-
-                /* both not NaN, do the comparison */
-                if (!isnan1 && !isnan2) {
-                    PER(temp1_double,temp2_double);
-
-                    if (not_comparable && !both_zero) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(LD_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                        }
-                        nfound++;
-                    }
-                    else if (per > opts->percent && ABS(temp1_double-temp2_double) > opts->delta) {
-                        if (print_data(opts)) {
-                            print_pos(ph, 1, idx, acc, pos, rank, dims, obj1, obj2);
-                            parallel_print(SPACES);
-                            parallel_print(LD_FORMAT_P, temp1_double, temp2_double, ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
-                        }
-                        nfound++;
-                    }
-                } /* NaN */
-                /* only one is NaN, assume difference */
-                else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            }
-            /*-------------------------------------------------------------------------
-             * no -d and -p
-             *-------------------------------------------------------------------------
-             */
-            else if (equal_ldouble(temp1_double, temp2_double, opts) == FALSE) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, idx, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LD_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                }
-                nfound++;
-            }
+            nfound += diff_ldouble_element(mem1, mem2, elemtno, opts);
         } /*H5T_NATIVE_LDOUBLE*/
 #endif  /* H5_SIZEOF_LONG_DOUBLE */
 
@@ -2038,8 +1152,8 @@ static hsize_t diff_region(hid_t obj1_id, hid_t obj2_id, hid_t region1_id, hid_t
         npoints1 = H5Sget_select_elem_npoints(region1_id);
         npoints2 = H5Sget_select_elem_npoints(region2_id);
     } H5E_END_TRY;
-    H5TOOLS_DEBUG("diff_region blocks: 1=%ld-2=%ld", nblocks1, nblocks2);
-    H5TOOLS_DEBUG("diff_region points: 1=%ld-2=%ld", npoints1, npoints2);
+    H5TOOLS_DEBUG("blocks: 1=%ld-2=%ld", nblocks1, nblocks2);
+    H5TOOLS_DEBUG("points: 1=%ld-2=%ld", npoints1, npoints2);
 
     if (nblocks1 != nblocks2 || npoints1 != npoints2 || ndims1 != ndims2) {
         opts->not_cmp = 1;
@@ -2087,8 +1201,9 @@ static hsize_t diff_region(hid_t obj1_id, hid_t obj2_id, hid_t region1_id, hid_t
                 }
 
                 /* print differences if found */
-                if (nfound_b && opts->m_verbose) {
+                if (nfound_b && opts->mode_verbose) {
                     H5O_info_t oi1, oi2;
+                    char *obj1_str = NULL, *obj2_str = NULL;
 
                     H5Oget_info2(obj1_id, &oi1, H5O_INFO_BASIC);
                     H5Oget_info2(obj2_id, &oi2, H5O_INFO_BASIC);
@@ -2147,7 +1262,7 @@ static hsize_t diff_region(hid_t obj1_id, hid_t obj2_id, hid_t region1_id, hid_t
                     }
                 }
 
-                if (nfound_p && opts->m_verbose) {
+                if (nfound_p && opts->mode_verbose) {
                     parallel_print("Region points\n");
                     for (i = 0; i < npoints1; i++) {
                         hsize_t pt1, pt2;
@@ -2207,8 +1322,7 @@ done:
  *-------------------------------------------------------------------------
  */
 
-static hsize_t character_compare(char *mem1, char *mem2, hsize_t i, size_t u,
-        int rank, hsize_t *dims, hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1, const char *obj2, int *ph)
+static hsize_t character_compare(char *mem1, char *mem2, hsize_t elemtno, ssize_t u, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* differences found */
     char    temp1_uchar;
@@ -2216,12 +1330,13 @@ static hsize_t character_compare(char *mem1, char *mem2, hsize_t i, size_t u,
 
     HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
     HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
-    H5TOOLS_START_DEBUG(" %d=%d",temp1_uchar,temp2_uchar);
+    H5TOOLS_START_DEBUG(" %d=%d", temp1_uchar, temp2_uchar);
 
     if (temp1_uchar != temp2_uchar) {
         if (print_data(opts)) {
-            print_char_pos(ph, 0, i, u, acc, pos, rank, dims, obj1, obj2);
-            parallel_print("            ");
+            opts->print_percentage = 0;
+            print_pos(opts, elemtno, u);
+            parallel_print("  ");
             h5diff_print_char(temp1_uchar);
             parallel_print("            ");
             h5diff_print_char(temp2_uchar);
@@ -2242,1953 +1357,1455 @@ static hsize_t character_compare(char *mem1, char *mem2, hsize_t i, size_t u,
  *-------------------------------------------------------------------------
  */
 
-static hsize_t character_compare_opt(unsigned char *mem1, unsigned char *mem2,
-        hsize_t i, int rank, hsize_t *dims, hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1, const char *obj2, int *ph)
+static hsize_t character_compare_opt(unsigned char *mem1, unsigned char *mem2, hsize_t elemtno, diff_opt_t *opts)
 {
     hsize_t       nfound = 0; /* differences found */
     unsigned char temp1_uchar;
     unsigned char temp2_uchar;
+    hbool_t       both_zero = FALSE;
     double        per;
-    hbool_t       both_zero;
 
     HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
     HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
+    H5TOOLS_START_DEBUG(" %d=%d", temp1_uchar, temp2_uchar);
 
     /* -d and !-p */
 
-    if (opts->d && !opts->p) {
+    if (opts->delta_bool && !opts->percent_bool) {
         if (PDIFF(temp1_uchar,temp2_uchar) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elemtno, -1);
             if (print_data(opts)) {
-                print_pos(ph, 0, i, acc, pos, rank, dims, obj1, obj2);
-                parallel_print(SPACES);
                 parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
             }
             nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
+    else if (!opts->delta_bool && opts->percent_bool) {
         PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
         if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elemtno, -1);
             if (print_data(opts)) {
-                print_pos(ph, 1, i, acc, pos, rank, dims, obj1, obj2);
-                parallel_print(SPACES);
                 parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
             }
             nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
+    else if (opts->delta_bool && opts->percent_bool) {
         PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
         if (per > opts->percent && PDIFF(temp1_uchar,temp2_uchar) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elemtno, -1);
             if (print_data(opts)) {
-                print_pos(ph, 1, i, acc, pos, rank, dims, obj1, obj2);
-                parallel_print(SPACES);
                 parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
             }
             nfound++;
         }
     }
     else if (temp1_uchar != temp2_uchar) {
+        opts->print_percentage = 0;
+        print_pos(opts, elemtno, -1);
         if (print_data(opts)) {
-            print_pos(ph, 0, i, acc, pos, rank, dims, obj1, obj2);
-            parallel_print(SPACES);
             parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
         }
         nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(": %d zero:%d", nfound, both_zero);
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_float
+ * Function: diff_float_element
  *
- * Purpose:  diff a H5T_NATIVE_FLOAT type
+ * Purpose:  diff a single H5T_NATIVE_FLOAT type
  *
  * Return:   number of differences found
 *
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_float(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims, hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
-
+static hsize_t diff_float_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* number of differences found */
     float   temp1_float;
     float   temp2_float;
-    hsize_t i;
     double  per;
-    hbool_t both_zero;
+    hbool_t both_zero = FALSE;
     hbool_t isnan1 = FALSE;
     hbool_t isnan2 = FALSE;
 
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
+
+    HDmemcpy(&temp1_float, mem1, sizeof(float));
+    HDmemcpy(&temp2_float, mem2, sizeof(float));
+
+    /* logic for detecting NaNs is different with opts -d, -p and no opts */
+
     /*-------------------------------------------------------------------------
      * -d and !-p
      *-------------------------------------------------------------------------
      */
+    if (opts->delta_bool && !opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+         * detect NaNs
+         *-------------------------------------------------------------------------
+         */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_float);
+            isnan2 = HDisnan(temp2_float);
+        }
 
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_float, mem1, sizeof(float));
-            HDmemcpy(&temp2_float, mem2, sizeof(float));
-
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_float);
-                isnan2 = HDisnan(temp2_float);
-            }
-
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                if ((double) ABS(temp1_float - temp2_float) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                    }
-                    nfound++;
-                }
-            }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            if ((double) ABS(temp1_float - temp2_float) > opts->delta) {
+                opts->print_percentage = 0;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
                     parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
                 }
                 nfound++;
-
             }
-            mem1 += sizeof(float);
-            mem2 += sizeof(float);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        }
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
+            }
+            nfound++;
+        }
     }
     /*-------------------------------------------------------------------------
-     * !-d and -p
-     *-------------------------------------------------------------------------
-     */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_float, mem1, sizeof(float));
-            HDmemcpy(&temp2_float, mem2, sizeof(float));
-
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_float);
-                isnan2 = HDisnan(temp2_float);
-            }
-            /* both not NaN, do the comparison */
-            if ((!isnan1 && !isnan2)) {
-                PER(temp1_float, temp2_float);
+    * !-d and -p
+    *-------------------------------------------------------------------------
+    */
+    else if (!opts->delta_bool && opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+         * detect NaNs
+         *-------------------------------------------------------------------------
+         */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_float);
+            isnan2 = HDisnan(temp2_float);
+        }
+        /* both not NaN, do the comparison */
+        if ((!isnan1 && !isnan2)) {
+            PER(temp1_float, temp2_float);
 
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P_NOTCOMP, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P, (double) temp1_float, (double) temp2_float,
-                                (double) ABS(temp1_float - temp2_float), (double) ABS(1 - temp2_float / temp1_float));
-                    }
-                    nfound++;
+            if (not_comparable && !both_zero) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
+                if (print_data(opts)) {
+                    parallel_print(F_FORMAT_P_NOTCOMP, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
                 }
+                nfound++;
             }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            else if (per > opts->percent) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
+                    parallel_print(F_FORMAT_P, (double) temp1_float, (double) temp2_float,
+                            (double) ABS(temp1_float - temp2_float), (double) ABS(1 - temp2_float / temp1_float));
                 }
                 nfound++;
-
             }
-            mem1 += sizeof(float);
-            mem2 += sizeof(float);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        }
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
+            }
+            nfound++;
+        }
     }
     /*-------------------------------------------------------------------------
-     * -d and -p
-     *-------------------------------------------------------------------------
-     */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_float, mem1, sizeof(float));
-            HDmemcpy(&temp2_float, mem2, sizeof(float));
-
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_float);
-                isnan2 = HDisnan(temp2_float);
-            }
+    * -d and -p
+    *-------------------------------------------------------------------------
+    */
+    else if (opts->delta_bool && opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+         * detect NaNs
+         *-------------------------------------------------------------------------
+         */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_float);
+            isnan2 = HDisnan(temp2_float);
+        }
 
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                PER(temp1_float, temp2_float);
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            PER(temp1_float, temp2_float);
 
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P_NOTCOMP, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && (double) ABS(temp1_float - temp2_float) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P, (double) temp1_float, (double) temp2_float,
-                                (double) ABS(temp1_float - temp2_float), (double) ABS(1 - temp2_float / temp1_float));
-                    }
-                    nfound++;
+            if (not_comparable && !both_zero) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
+                if (print_data(opts)) {
+                    parallel_print(F_FORMAT_P_NOTCOMP, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
                 }
-
+                nfound++;
             }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            else if (per > opts->percent && (double) ABS(temp1_float - temp2_float) > opts->delta) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
+                    parallel_print(F_FORMAT_P, (double) temp1_float, (double) temp2_float,
+                            (double) ABS(temp1_float - temp2_float), (double) ABS(1 - temp2_float / temp1_float));
                 }
                 nfound++;
-
             }
-            mem1 += sizeof(float);
-            mem2 += sizeof(float);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        }
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
+            }
+            nfound++;
+        }
     }
-
     /*-------------------------------------------------------------------------
-     * no -d and -p
-     *-------------------------------------------------------------------------
-     */
+    * no -d and -p
+    *-------------------------------------------------------------------------
+    */
     else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_float, mem1, sizeof(float));
-            HDmemcpy(&temp2_float, mem2, sizeof(float));
-
-            if (equal_float(temp1_float, temp2_float, opts) == FALSE) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
-                }
-                nfound++;
+        if (equal_float(temp1_float, temp2_float, opts) == FALSE) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, (double) temp1_float, (double) temp2_float, (double) ABS(temp1_float - temp2_float));
             }
-
-            mem1 += sizeof(float);
-            mem2 += sizeof(float);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+            nfound++;
+        }
     }
 
+    H5TOOLS_ENDDEBUG(": %d zero:%d", nfound, both_zero);
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_double
+ * Function: diff_double_element
  *
- * Purpose:  diff a H5T_NATIVE_DOUBLE type
+ * Purpose:  diff a single H5T_NATIVE_DOUBLE type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_double(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
-
+static hsize_t diff_double_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* number of differences found */
     double  temp1_double;
     double  temp2_double;
-    hsize_t i;
     double  per;
-    hbool_t both_zero;
+    hbool_t both_zero = FALSE;
     hbool_t isnan1 = FALSE;
     hbool_t isnan2 = FALSE;
 
-    /*-------------------------------------------------------------------------
-     * -d and !-p
-     *-------------------------------------------------------------------------
-     */
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_double, mem1, sizeof(double));
-            HDmemcpy(&temp2_double, mem2, sizeof(double));
+    HDmemcpy(&temp1_double, mem1, sizeof(double));
+    HDmemcpy(&temp2_double, mem2, sizeof(double));
 
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_double);
-                isnan2 = HDisnan(temp2_double);
-            }
+    /*-------------------------------------------------------------------------
+    * -d and !-p
+    *-------------------------------------------------------------------------
+    */
+    if (opts->delta_bool && !opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+        * detect NaNs
+        *-------------------------------------------------------------------------
+        */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_double);
+            isnan2 = HDisnan(temp2_double);
+        }
 
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                if (ABS(temp1_double-temp2_double) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            if (ABS(temp1_double-temp2_double) > opts->delta) {
+                opts->print_percentage = 0;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
                     parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
                 }
                 nfound++;
-
             }
-            mem1 += sizeof(double);
-            mem2 += sizeof(double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        }
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+            }
+            nfound++;
+        }
     }
 
     /*-------------------------------------------------------------------------
-     * !-d and -p
-     *-------------------------------------------------------------------------
-     */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_double, mem1, sizeof(double));
-            HDmemcpy(&temp2_double, mem2, sizeof(double));
-
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_double);
-                isnan2 = HDisnan(temp2_double);
-            }
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                PER(temp1_double, temp2_double);
+    * !-d and -p
+    *-------------------------------------------------------------------------
+    */
+    else if (!opts->delta_bool && opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+        * detect NaNs
+        *-------------------------------------------------------------------------
+        */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_double);
+            isnan2 = HDisnan(temp2_double);
+        }
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            PER(temp1_double, temp2_double);
 
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P, temp1_double, temp2_double,
-                                ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
-                    }
-                    nfound++;
+            if (not_comparable && !both_zero) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
+                if (print_data(opts)) {
+                    parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
                 }
+                nfound++;
             }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            else if (per > opts->percent) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+                    parallel_print(F_FORMAT_P, temp1_double, temp2_double,
+                            ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
                 }
                 nfound++;
-
             }
-            mem1 += sizeof(double);
-            mem2 += sizeof(double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        }
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+            }
+            nfound++;
+        }
     }
     /*-------------------------------------------------------------------------
-     * -d and -p
-     *-------------------------------------------------------------------------
-     */
-    else if (opts->d && opts->p) {
-
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_double, mem1, sizeof(double));
-            HDmemcpy(&temp2_double, mem2, sizeof(double));
-
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_double);
-                isnan2 = HDisnan(temp2_double);
-            }
+    * -d and -p
+    *-------------------------------------------------------------------------
+    */
+    else if (opts->delta_bool && opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+        * detect NaNs
+        *-------------------------------------------------------------------------
+        */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_double);
+            isnan2 = HDisnan(temp2_double);
+        }
 
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                PER(temp1_double, temp2_double);
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            PER(temp1_double, temp2_double);
 
-                if (not_comparable && !both_zero)  {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && ABS(temp1_double-temp2_double) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P, temp1_double, temp2_double,
-                                ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
-                    }
-                    nfound++;
+            if (not_comparable && !both_zero)  {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
+                if (print_data(opts)) {
+                    parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
                 }
+                nfound++;
             }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            else if (per > opts->percent && ABS(temp1_double-temp2_double) > opts->delta) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+                    parallel_print(F_FORMAT_P, temp1_double, temp2_double,
+                            ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
                 }
                 nfound++;
             }
-            mem1 += sizeof(double);
-            mem2 += sizeof(double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        }
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+            }
+            nfound++;
+        }
     }
     /*-------------------------------------------------------------------------
-     * no -d and -p
-     *-------------------------------------------------------------------------
-     */
+    * no -d and -p
+    *-------------------------------------------------------------------------
+    */
     else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_double, mem1, sizeof(double));
-            HDmemcpy(&temp2_double, mem2, sizeof(double));
-
-            if (equal_double(temp1_double, temp2_double, opts) == FALSE) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                }
-                nfound++;
+        if (equal_double(temp1_double, temp2_double, opts) == FALSE) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
             }
-
-            mem1 += sizeof(double);
-            mem2 += sizeof(double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+            nfound++;
+        }
     }
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
 
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_ldouble
+ * Function: diff_ldouble_element
  *
- * Purpose:  diff a H5T_NATIVE_LDOUBLE type
+ * Purpose:  diff a single H5T_NATIVE_LDOUBLE type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
 #if H5_SIZEOF_LONG_DOUBLE !=0
 
-static hsize_t diff_ldouble(unsigned char *mem1,
-        unsigned char *mem2,
-        hsize_t nelmts,
-        hsize_t hyper_start,
-        int rank,
-        hsize_t *dims,
-        hsize_t *acc,
-        hsize_t *pos,
-        diff_opt_t *opts,
-        const char *obj1,
-        const char *obj2,
-        int *ph)
-
+static hsize_t diff_ldouble_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t     nfound = 0; /* number of differences found */
     long double temp1_double;
     long double temp2_double;
-    hsize_t     i;
     double      per;
-    hbool_t     both_zero;
+    hbool_t     both_zero = FALSE;
     hbool_t     isnan1 = FALSE;
     hbool_t     isnan2 = FALSE;
 
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
+
+    HDmemcpy(&temp1_double, mem1, sizeof(long double));
+    HDmemcpy(&temp2_double, mem2, sizeof(long double));
+
+    /* logic for detecting NaNs is different with options -d, -p and no options */
+
     /*-------------------------------------------------------------------------
      * -d and !-p
      *-------------------------------------------------------------------------
      */
+    if (opts->delta_bool && !opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+         * detect NaNs
+         *-------------------------------------------------------------------------
+         */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_double);
+            isnan2 = HDisnan(temp2_double);
+        }
 
-    if (opts->d && !opts->p) {
-        for ( i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_double, mem1, sizeof(long double));
-            HDmemcpy(&temp2_double, mem2, sizeof(long double));
-
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_double);
-                isnan2 = HDisnan(temp2_double);
-            }
-
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                if (ABS(temp1_double-temp2_double) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-            }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            if (ABS(temp1_double-temp2_double) > opts->delta) {
+                opts->print_percentage = 0;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+                    parallel_print(LD_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
                 }
                 nfound++;
-
             }
-            mem1 += sizeof(long double);
-            mem2 += sizeof(long double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        } /* NaN */
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+            }
+            nfound++;
+        }
     }
-
     /*-------------------------------------------------------------------------
      * !-d and -p
      *-------------------------------------------------------------------------
      */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_double, mem1, sizeof(long double));
-            HDmemcpy(&temp2_double, mem2, sizeof(long double));
+    else if (!opts->delta_bool && opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+         * detect NaNs
+         *-------------------------------------------------------------------------
+         */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_double);
+            isnan2 = HDisnan(temp2_double);
+        }
 
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_double);
-                isnan2 = HDisnan(temp2_double);
-            }
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                PER(temp1_double, temp2_double);
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            PER(temp1_double,temp2_double);
 
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P, temp1_double, temp2_double,
-                                ABS(temp1_double - temp2_double), ABS(1-temp2_double / temp1_double));
-                    }
-                    nfound++;
+            if (not_comparable && !both_zero) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
+                if (print_data(opts)) {
+                    parallel_print(LD_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
                 }
+                nfound++;
             }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            else if (per > opts->percent) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
                 if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start+i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+                    parallel_print(LD_FORMAT_P, temp1_double, temp2_double, ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
                 }
                 nfound++;
             }
-            mem1 += sizeof(long double);
-            mem2 += sizeof(long double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        } /* NaN */
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+            }
+            nfound++;
+        }
     }
     /*-------------------------------------------------------------------------
      * -d and -p
      *-------------------------------------------------------------------------
      */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_double, mem1, sizeof(long double));
-            HDmemcpy(&temp2_double, mem2, sizeof(long double));
-
-            /*-------------------------------------------------------------------------
-             * detect NaNs
-             *-------------------------------------------------------------------------
-             */
-            if (opts->do_nans) {
-                isnan1 = HDisnan(temp1_double);
-                isnan2 = HDisnan(temp2_double);
-            }
+    else if (opts->delta_bool && opts->percent_bool) {
+        /*-------------------------------------------------------------------------
+         * detect NaNs
+         *-------------------------------------------------------------------------
+         */
+        if (opts->do_nans) {
+            isnan1 = HDisnan(temp1_double);
+            isnan2 = HDisnan(temp2_double);
+        }
 
-            /* both not NaN, do the comparison */
-            if (!isnan1 && !isnan2) {
-                PER(temp1_double, temp2_double);
+        /* both not NaN, do the comparison */
+        if (!isnan1 && !isnan2) {
+            PER(temp1_double,temp2_double);
 
-                if (not_comparable && !both_zero) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                    }
-                    nfound++;
-                }
-                else if (per > opts->percent && ABS(temp1_double - temp2_double) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(F_FORMAT_P, temp1_double, temp2_double, ABS(temp1_double - temp2_double), ABS(1-temp2_double / temp1_double));
-                    }
-                    nfound++;
+            if (not_comparable && !both_zero) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
+                if (print_data(opts)) {
+                    parallel_print(LD_FORMAT_P_NOTCOMP, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
                 }
+                nfound++;
             }
-            /* only one is NaN, assume difference */
-            else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
-                if (print_data(opts))  {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+            else if (per > opts->percent && ABS(temp1_double-temp2_double) > opts->delta) {
+                opts->print_percentage = 1;
+                print_pos(opts, elem_idx, -1);
+                if (print_data(opts)) {
+                    parallel_print(LD_FORMAT_P, temp1_double, temp2_double, ABS(temp1_double - temp2_double), ABS(1 - temp2_double / temp1_double));
                 }
                 nfound++;
             }
-            mem1 += sizeof(long double);
-            mem2 += sizeof(long double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* i */
+        } /* NaN */
+        /* only one is NaN, assume difference */
+        else if ((isnan1 && !isnan2) || (!isnan1 && isnan2)) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+            }
+            nfound++;
+        }
     }
     /*-------------------------------------------------------------------------
      * no -d and -p
      *-------------------------------------------------------------------------
      */
-    else {
-        for (i = 0; i < nelmts; i++)  {
-            HDmemcpy(&temp1_double, mem1, sizeof(long double));
-            HDmemcpy(&temp2_double, mem2, sizeof(long double));
-
-            if (equal_ldouble(temp1_double, temp2_double, opts) == FALSE) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(F_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
-                }
-                nfound++;
-            }
-            mem1 += sizeof(long double);
-            mem2 += sizeof(long double);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (equal_ldouble(temp1_double, temp2_double, opts) == FALSE) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(LD_FORMAT, temp1_double, temp2_double, ABS(temp1_double - temp2_double));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 #endif /* H5_SIZEOF_LONG_DOUBLE */
 
 /*-------------------------------------------------------------------------
- * Function: diff_schar
+ * Function: diff_schar_element
  *
- * Purpose:  diff a H5T_NATIVE_SCHAR type
+ * Purpose:  diff a single H5T_NATIVE_SCHAR type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_schar(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
-
+static hsize_t diff_schar_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* number of differences found */
     char    temp1_char;
     char    temp2_char;
-    hsize_t i;
     double  per;
-    hbool_t both_zero;
+    hbool_t both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_char, mem1, sizeof(char));
-            HDmemcpy(&temp2_char, mem2, sizeof(char));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
+    HDmemcpy(&temp1_char, mem1, sizeof(char));
+    HDmemcpy(&temp2_char, mem2, sizeof(char));
 
-            if (ABS(temp1_char-temp2_char) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                }
-                nfound++;
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (ABS(temp1_char-temp2_char) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
             }
-            mem1 += sizeof(char);
-            mem2 += sizeof(char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_char, mem1, sizeof(char));
-            HDmemcpy(&temp2_char, mem2, sizeof(char));
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER(temp1_char, temp2_char);
 
-            PER(temp1_char, temp2_char);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_char, temp2_char, ABS(temp1_char - temp2_char), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_char, temp2_char, ABS(temp1_char - temp2_char), per);
             }
-            mem1 += sizeof(char);
-            mem2 += sizeof(char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_char, mem1, sizeof(char));
-            HDmemcpy(&temp2_char, mem2, sizeof(char));
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER(temp1_char, temp2_char);
 
-            PER(temp1_char, temp2_char);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
             }
-            else if (per > opts->percent && ABS(temp1_char-temp2_char) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_char, temp2_char, ABS(temp1_char - temp2_char), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && ABS(temp1_char - temp2_char) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_char, temp2_char, ABS(temp1_char - temp2_char), per);
             }
-            mem1 += sizeof(char);
-            mem2 += sizeof(char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_char, mem1, sizeof(char));
-            HDmemcpy(&temp2_char, mem2, sizeof(char));
-
-            if (temp1_char != temp2_char) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
-                }
-                nfound++;
-            }
-
-            mem1 += sizeof(char);
-            mem2 += sizeof(char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (temp1_char != temp2_char) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(I_FORMAT, temp1_char, temp2_char, ABS(temp1_char - temp2_char));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_uchar
+ * Function: diff_uchar_element
  *
- * Purpose:  diff a H5T_NATIVE_UCHAR type
+ * Purpose:  diff a single H5T_NATIVE_UCHAR type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_uchar(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
+static hsize_t diff_uchar_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t       nfound = 0; /* number of differences found */
     unsigned char temp1_uchar;
     unsigned char temp2_uchar;
-    hsize_t       i;
     double        per;
-    hbool_t       both_zero;
+    hbool_t       both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
-            HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-            if (PDIFF(temp1_uchar,temp2_uchar) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                }
-                nfound++;
+    HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
+    HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (PDIFF(temp1_uchar, temp2_uchar) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
             }
-            mem1 += sizeof(unsigned char);
-            mem2 += sizeof(unsigned char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
-            HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
-
-            PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
             }
-            mem1 += sizeof(unsigned char);
-            mem2 += sizeof(unsigned char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
-            HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
-
-            PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed char, temp1_uchar, temp2_uchar);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
             }
-            else if (per > opts->percent && PDIFF(temp1_uchar,temp2_uchar) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && PDIFF(temp1_uchar, temp2_uchar) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar), per);
             }
-            mem1 += sizeof(unsigned char);
-            mem2 += sizeof(unsigned char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uchar, mem1, sizeof(unsigned char));
-            HDmemcpy(&temp2_uchar, mem2, sizeof(unsigned char));
-
-            if (temp1_uchar != temp2_uchar) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
-                }
-                nfound++;
-            }
-
-            mem1 += sizeof(unsigned char);
-            mem2 += sizeof(unsigned char);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (temp1_uchar != temp2_uchar) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(I_FORMAT, temp1_uchar, temp2_uchar, PDIFF(temp1_uchar, temp2_uchar));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_short
+ * Function: diff_short_element
  *
  * Purpose:  diff a H5T_NATIVE_SHORT type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_short(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
+static hsize_t diff_short_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* number of differences found */
     short   temp1_short;
     short   temp2_short;
-    hsize_t i;
     double  per;
-    hbool_t both_zero;
+    hbool_t both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_short, mem1, sizeof(short));
-            HDmemcpy(&temp2_short, mem2, sizeof(short));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-            if (ABS(temp1_short-temp2_short) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                }
-                nfound++;
+    HDmemcpy(&temp1_short, mem1, sizeof(short));
+    HDmemcpy(&temp2_short, mem2, sizeof(short));
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (ABS(temp1_short - temp2_short) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
             }
-            mem1 += sizeof(short);
-            mem2 += sizeof(short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_short, mem1, sizeof(short));
-            HDmemcpy(&temp2_short, mem2, sizeof(short));
-
-            PER(temp1_short, temp2_short);
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER(temp1_short, temp2_short);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_short, temp2_short, ABS(temp1_short - temp2_short), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_short, temp2_short, ABS(temp1_short - temp2_short), per);
             }
-            mem1 += sizeof(short);
-            mem2 += sizeof(short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_short, mem1, sizeof(short));
-            HDmemcpy(&temp2_short, mem2, sizeof(short));
-
-            PER(temp1_short, temp2_short);
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER(temp1_short, temp2_short);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
             }
-            else if (per > opts->percent && ABS(temp1_short-temp2_short) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_short, temp2_short, ABS(temp1_short - temp2_short), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && ABS(temp1_short - temp2_short) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_short, temp2_short, ABS(temp1_short - temp2_short), per);
             }
-            mem1 += sizeof(short);
-            mem2 += sizeof(short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_short, mem1, sizeof(short));
-            HDmemcpy(&temp2_short, mem2, sizeof(short));
-
-            if (temp1_short != temp2_short) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
-                }
-                nfound++;
-            }
-
-            mem1 += sizeof(short);
-            mem2 += sizeof(short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (temp1_short != temp2_short) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(I_FORMAT, temp1_short, temp2_short, ABS(temp1_short - temp2_short));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_ushort
+ * Function: diff_ushort_element
  *
- * Purpose:  diff a H5T_NATIVE_USHORT type
+ * Purpose:  diff a single H5T_NATIVE_USHORT type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_ushort(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
-
+static hsize_t diff_ushort_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t        nfound = 0; /* number of differences found */
     unsigned short temp1_ushort;
     unsigned short temp2_ushort;
-    hsize_t        i;
     double         per;
-    hbool_t        both_zero;
+    hbool_t        both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ushort, mem1, sizeof(unsigned short));
-            HDmemcpy(&temp2_ushort, mem2, sizeof(unsigned short));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-            if (PDIFF(temp1_ushort,temp2_ushort) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                }
-                nfound++;
+    HDmemcpy(&temp1_ushort, mem1, sizeof(unsigned short));
+    HDmemcpy(&temp2_ushort, mem2, sizeof(unsigned short));
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (PDIFF(temp1_ushort, temp2_ushort) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
             }
-            mem1 += sizeof(unsigned short);
-            mem2 += sizeof(unsigned short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ushort, mem1, sizeof(unsigned short));
-            HDmemcpy(&temp2_ushort, mem2, sizeof(unsigned short));
-
-            PER_UNSIGN(signed short, temp1_ushort, temp2_ushort);
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed short, temp1_ushort, temp2_ushort);
 
-            if (not_comparable && !both_zero)  {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort), per);
             }
-            mem1 += sizeof(unsigned short);
-            mem2 += sizeof(unsigned short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ushort, mem1, sizeof(unsigned short));
-            HDmemcpy(&temp2_ushort, mem2, sizeof(unsigned short));
-
-            PER_UNSIGN(signed short, temp1_ushort, temp2_ushort);
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed short, temp1_ushort, temp2_ushort);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
             }
-            else if (per > opts->percent && PDIFF(temp1_ushort,temp2_ushort) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && PDIFF(temp1_ushort, temp2_ushort) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort), per);
             }
-            mem1 += sizeof(unsigned short);
-            mem2 += sizeof(unsigned short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ushort, mem1, sizeof(unsigned short));
-            HDmemcpy(&temp2_ushort, mem2, sizeof(unsigned short));
-
-            if (temp1_ushort != temp2_ushort) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
-                }
-                nfound++;
-            }
-
-            mem1 += sizeof(unsigned short);
-            mem2 += sizeof(unsigned short);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (temp1_ushort != temp2_ushort) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(I_FORMAT, temp1_ushort, temp2_ushort, PDIFF(temp1_ushort, temp2_ushort));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function:  diff_int
+ * Function:  diff_int_element
  *
- * Purpose:   diff a H5T_NATIVE_INT type
+ * Purpose:   diff a single H5T_NATIVE_INT type
  *
  * Return:    number of differences found
   *-------------------------------------------------------------------------
  */
-static hsize_t diff_int(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
+static hsize_t diff_int_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* number of differences found */
     int     temp1_int;
     int     temp2_int;
-    hsize_t i;
     double  per;
-    hbool_t both_zero;
+    hbool_t both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_int, mem1, sizeof(int));
-            HDmemcpy(&temp2_int, mem2, sizeof(int));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-            if (ABS(temp1_int-temp2_int) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                }
-                nfound++;
+    HDmemcpy(&temp1_int, mem1, sizeof(int));
+    HDmemcpy(&temp2_int, mem2, sizeof(int));
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (ABS(temp1_int-temp2_int) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
             }
-            mem1 += sizeof(int);
-            mem2 += sizeof(int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_int, mem1, sizeof(int));
-            HDmemcpy(&temp2_int, mem2, sizeof(int));
-
-            PER(temp1_int, temp2_int);
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER(temp1_int, temp2_int);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_int, temp2_int, ABS(temp1_int - temp2_int), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_int, temp2_int, ABS(temp1_int - temp2_int), per);
             }
-            mem1 += sizeof(int);
-            mem2 += sizeof(int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_int, mem1, sizeof(int));
-            HDmemcpy(&temp2_int, mem2, sizeof(int));
-
-            PER(temp1_int, temp2_int);
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER(temp1_int, temp2_int);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P_NOTCOMP, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
             }
-            else if (per > opts->percent && ABS(temp1_int-temp2_int) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_int, temp2_int, ABS(temp1_int - temp2_int), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && ABS(temp1_int - temp2_int) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(I_FORMAT_P, temp1_int, temp2_int, ABS(temp1_int - temp2_int), per);
             }
-            mem1 += sizeof(int);
-            mem2 += sizeof(int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_int, mem1, sizeof(int));
-            HDmemcpy(&temp2_int, mem2, sizeof(int));
-
-            if (temp1_int != temp2_int) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
-                }
-                nfound++;
-            }
+    else if (temp1_int != temp2_int) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(I_FORMAT, temp1_int, temp2_int, ABS(temp1_int - temp2_int));
+        }
+        nfound++;
+    }
 
-            mem1 += sizeof(int);
-            mem2 += sizeof(int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
 
-    }
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_uint
+ * Function: diff_uint_element
  *
- * Purpose:  diff a H5T_NATIVE_UINT type
+ * Purpose:  diff a single H5T_NATIVE_UINT type
  *
  * Return:  number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_uint(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
+static hsize_t diff_uint_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* number of differences found */
     unsigned int temp1_uint;
     unsigned int temp2_uint;
-    hsize_t i;
     double per;
-    hbool_t both_zero;
+    hbool_t both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uint, mem1, sizeof(unsigned int));
-            HDmemcpy(&temp2_uint, mem2, sizeof(unsigned int));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-            if (PDIFF(temp1_uint,temp2_uint) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                }
-                nfound++;
+    HDmemcpy(&temp1_uint, mem1, sizeof(unsigned int));
+    HDmemcpy(&temp2_uint, mem2, sizeof(unsigned int));
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (PDIFF(temp1_uint, temp2_uint) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(UI_FORMAT, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
             }
-            mem1 += sizeof(unsigned int);
-            mem2 += sizeof(unsigned int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uint, mem1, sizeof(unsigned int));
-            HDmemcpy(&temp2_uint, mem2, sizeof(unsigned int));
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed int, temp1_uint, temp2_uint);
 
-            PER_UNSIGN(signed int, temp1_uint, temp2_uint);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(UI_FORMAT_P_NOTCOMP, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(UI_FORMAT_P, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint), per);
             }
-            mem1 += sizeof(unsigned int);
-            mem2 += sizeof(unsigned int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uint, mem1, sizeof(unsigned int));
-            HDmemcpy(&temp2_uint, mem2, sizeof(unsigned int));
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed int, temp1_uint, temp2_uint);
 
-            PER_UNSIGN(signed int, temp1_uint, temp2_uint);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P_NOTCOMP, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(UI_FORMAT_P_NOTCOMP, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
             }
-            else if (per > opts->percent
-                    && PDIFF(temp1_uint,temp2_uint) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT_P, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && PDIFF(temp1_uint,temp2_uint) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(UI_FORMAT_P, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint), per);
             }
-            mem1 += sizeof(unsigned int);
-            mem2 += sizeof(unsigned int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_uint, mem1, sizeof(unsigned int));
-            HDmemcpy(&temp2_uint, mem2, sizeof(unsigned int));
-
-            if (temp1_uint != temp2_uint) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(I_FORMAT, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
-                }
-                nfound++;
-            }
-
-            mem1 += sizeof(unsigned int);
-            mem2 += sizeof(unsigned int);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (temp1_uint != temp2_uint) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(UI_FORMAT, temp1_uint, temp2_uint, PDIFF(temp1_uint, temp2_uint));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_long
+ * Function: diff_long_element
  *
- * Purpose:  diff a H5T_NATIVE_LONG type
+ * Purpose:  diff a single H5T_NATIVE_LONG type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_long(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
+static hsize_t diff_long_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t nfound = 0; /* number of differences found */
     long temp1_long;
     long temp2_long;
-    hsize_t i;
     double per;
-    hbool_t both_zero;
+    hbool_t both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            for (i = 0; i < nelmts; i++) {
-                HDmemcpy(&temp1_long, mem1, sizeof(long));
-                HDmemcpy(&temp2_long, mem2, sizeof(long));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-                if (ABS(temp1_long-temp2_long) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(LI_FORMAT, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                    }
-                    nfound++;
-                }
-                mem1 += sizeof(long);
-                mem2 += sizeof(long);
-                if (opts->n && nfound >= opts->count)
-                    return nfound;
+    HDmemcpy(&temp1_long, mem1, sizeof(long));
+    HDmemcpy(&temp2_long, mem2, sizeof(long));
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (ABS(temp1_long-temp2_long) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LI_FORMAT, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
             }
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_long, mem1, sizeof(long));
-            HDmemcpy(&temp2_long, mem2, sizeof(long));
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER(temp1_long, temp2_long);
 
-            PER(temp1_long, temp2_long);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT_P_NOTCOMP, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LI_FORMAT_P_NOTCOMP, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT_P, temp1_long, temp2_long, ABS(temp1_long - temp2_long), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LI_FORMAT_P, temp1_long, temp2_long, ABS(temp1_long - temp2_long), per);
             }
-            mem1 += sizeof(long);
-            mem2 += sizeof(long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_long, mem1, sizeof(long));
-            HDmemcpy(&temp2_long, mem2, sizeof(long));
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER(temp1_long, temp2_long);
 
-            PER(temp1_long, temp2_long);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT_P_NOTCOMP, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LI_FORMAT_P_NOTCOMP, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
             }
-            else if (per > opts->percent && ABS(temp1_long-temp2_long) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT_P, temp1_long, temp2_long, ABS(temp1_long - temp2_long), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && ABS(temp1_long-temp2_long) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LI_FORMAT_P, temp1_long, temp2_long, ABS(temp1_long - temp2_long), per);
             }
-            mem1 += sizeof(long);
-            mem2 += sizeof(long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_long, mem1, sizeof(long));
-            HDmemcpy(&temp2_long, mem2, sizeof(long));
-
-            if (temp1_long != temp2_long) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
-                }
-                nfound++;
-            }
-
-            mem1 += sizeof(long);
-            mem2 += sizeof(long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (temp1_long != temp2_long) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(LI_FORMAT, temp1_long, temp2_long, ABS(temp1_long - temp2_long));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_ulong
+ * Function: diff_ulong_element
  *
- * Purpose:  diff a H5T_NATIVE_ULONG type
+ * Purpose:  diff a single H5T_NATIVE_ULONG type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_ulong(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
+static hsize_t diff_ulong_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t       nfound = 0; /* number of differences found */
     unsigned long temp1_ulong;
     unsigned long temp2_ulong;
-    hsize_t       i;
     double        per;
-    hbool_t       both_zero;
+    hbool_t       both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            for (i = 0; i < nelmts; i++) {
-                HDmemcpy(&temp1_ulong, mem1, sizeof(unsigned long));
-                HDmemcpy(&temp2_ulong, mem2, sizeof(unsigned long));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-                if (PDIFF(temp1_ulong,temp2_ulong) > opts->delta) {
-                    if (print_data(opts)) {
-                        print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                        parallel_print(SPACES);
-                        parallel_print(LI_FORMAT, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                    }
-                    nfound++;
-                }
-                mem1 += sizeof(unsigned long);
-                mem2 += sizeof(unsigned long);
-                if (opts->n && nfound >= opts->count)
-                    return nfound;
+    HDmemcpy(&temp1_ulong, mem1, sizeof(unsigned long));
+    HDmemcpy(&temp2_ulong, mem2, sizeof(unsigned long));
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (PDIFF(temp1_ulong, temp2_ulong) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULI_FORMAT, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
             }
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ulong, mem1, sizeof(unsigned long));
-            HDmemcpy(&temp2_ulong, mem2, sizeof(unsigned long));
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed long, temp1_ulong, temp2_ulong);
 
-            PER_UNSIGN(signed long, temp1_ulong, temp2_ulong);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULI_FORMAT_P_NOTCOMP, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULI_FORMAT_P_NOTCOMP, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT_P, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULI_FORMAT_P, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong), per);
             }
-            mem1 += sizeof(unsigned long);
-            mem2 += sizeof(unsigned long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ulong, mem1, sizeof(unsigned long));
-            HDmemcpy(&temp2_ulong, mem2, sizeof(unsigned long));
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER_UNSIGN(signed long, temp1_ulong, temp2_ulong);
 
-            PER_UNSIGN(signed long, temp1_ulong, temp2_ulong);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULI_FORMAT_P_NOTCOMP, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULI_FORMAT_P_NOTCOMP, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
             }
-            else if (per > opts->percent
-                    && PDIFF(temp1_ulong,temp2_ulong) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT_P, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong), per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && PDIFF(temp1_ulong,temp2_ulong) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULI_FORMAT_P, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong), per);
             }
-            mem1 += sizeof(unsigned long);
-            mem2 += sizeof(unsigned long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
-    else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ulong, mem1, sizeof(unsigned long));
-            HDmemcpy(&temp2_ulong, mem2, sizeof(unsigned long));
-
-            if (temp1_ulong != temp2_ulong) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LI_FORMAT, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
-                }
-                nfound++;
-            }
-
-            mem1 += sizeof(unsigned long);
-            mem2 += sizeof(unsigned long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+    else if (temp1_ulong != temp2_ulong) {
+        opts->print_percentage = 0;
+        print_pos(opts, elem_idx, -1);
+        if (print_data(opts)) {
+            parallel_print(ULI_FORMAT, temp1_ulong, temp2_ulong, PDIFF(temp1_ulong, temp2_ulong));
+        }
+        nfound++;
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_llong
+ * Function: diff_llong_element
  *
- * Purpose:  diff a H5T_NATIVE_LLONG type
+ * Purpose:  diff a single H5T_NATIVE_LLONG type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_llong(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims,
-        hsize_t *acc, hsize_t *pos, diff_opt_t *opts, const char *obj1,
-        const char *obj2, int *ph)
+static hsize_t diff_llong_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t   nfound = 0; /* number of differences found */
     long long temp1_llong;
     long long temp2_llong;
-    hsize_t   i;
     double    per;
-    hbool_t   both_zero;
+    hbool_t   both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_llong, mem1, sizeof(long long));
-            HDmemcpy(&temp2_llong, mem2, sizeof(long long));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-            if (ABS( temp1_llong-temp2_llong) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LLI_FORMAT, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong));
-                }
-                nfound++;
+    HDmemcpy(&temp1_llong, mem1, sizeof(long long));
+    HDmemcpy(&temp2_llong, mem2, sizeof(long long));
+
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (ABS( temp1_llong-temp2_llong) > opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LLI_FORMAT, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong));
             }
-            mem1 += sizeof(long long);
-            mem2 += sizeof(long long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_llong, mem1, sizeof(long long));
-            HDmemcpy(&temp2_llong, mem2, sizeof(long long));
-
-            PER(temp1_llong, temp2_llong);
+    else if (!opts->delta_bool && opts->percent_bool) {
+        PER(temp1_llong, temp2_llong);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
                 parallel_print(LLI_FORMAT_P_NOTCOMP, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong));
             }
             nfound++;
         }
         else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
             if (print_data(opts)) {
-                print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                parallel_print(SPACES);
                 parallel_print(LLI_FORMAT_P, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong),per);
             }
             nfound++;
         }
-        mem1 += sizeof(long long);
-        mem2 += sizeof(long long);
-        if (opts->n && nfound >= opts->count)
-            return nfound;
-        }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_llong, mem1, sizeof(long long));
-            HDmemcpy(&temp2_llong, mem2, sizeof(long long));
-
-            PER(temp1_llong, temp2_llong);
+    else if (opts->delta_bool && opts->percent_bool) {
+        PER(temp1_llong, temp2_llong);
 
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LLI_FORMAT_P_NOTCOMP, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong));
-                }
-                nfound++;
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LLI_FORMAT_P_NOTCOMP, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong));
             }
-            else if (per > opts->percent
-                    && ABS(temp1_llong-temp2_llong) > opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LLI_FORMAT_P, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong),per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && ABS(temp1_llong-temp2_llong) > opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LLI_FORMAT_P, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong),per);
             }
-            mem1 += sizeof(long long);
-            mem2 += sizeof(long long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_llong, mem1, sizeof(long long));
-            HDmemcpy(&temp2_llong, mem2, sizeof(long long));
-
-            if (temp1_llong != temp2_llong) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(LLI_FORMAT, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong));
-                }
-                nfound++;
+        if (temp1_llong != temp2_llong) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(LLI_FORMAT, temp1_llong, temp2_llong, ABS(temp1_llong - temp2_llong));
             }
-
-            mem1 += sizeof(long long);
-            mem2 += sizeof(long long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+            nfound++;
+        }
     }
 
+    H5TOOLS_ENDDEBUG(":%d - errstat:%d", nfound, opts->err_stat);
+
     return nfound;
 }
 
 /*-------------------------------------------------------------------------
- * Function: diff_ullong
+ * Function: diff_ullong_element
  *
- * Purpose:  diff a H5T_NATIVE_ULLONG type
+ * Purpose:  diff a single H5T_NATIVE_ULLONG type
  *
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-static hsize_t diff_ullong(unsigned char *mem1, unsigned char *mem2,
-        hsize_t nelmts, hsize_t hyper_start, int rank, hsize_t *dims, hsize_t *acc,
-        hsize_t *pos, diff_opt_t *opts, const char *obj1, const char *obj2, int *ph)
-
+static hsize_t diff_ullong_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
 {
     hsize_t            nfound = 0; /* number of differences found */
     unsigned long long temp1_ullong;
     unsigned long long temp2_ullong;
-    hsize_t            i;
     float              f1, f2;
     double             per;
-    hbool_t            both_zero;
+    hbool_t            both_zero = FALSE;
 
-    /* -d and !-p */
-    if (opts->d && !opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ullong, mem1, sizeof(unsigned long long));
-            HDmemcpy(&temp2_ullong, mem2, sizeof(unsigned long long));
+    H5TOOLS_START_DEBUG("delta_bool:%d - percent_bool:%d", opts->delta_bool, opts->percent_bool);
 
-            if (PDIFF(temp1_ullong,temp2_ullong) > (unsigned long long) opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULLI_FORMAT,temp1_ullong,temp2_ullong,PDIFF(temp1_ullong,temp2_ullong));
-                }
-                nfound++;
+    HDmemcpy(&temp1_ullong, mem1, sizeof(unsigned long long));
+    HDmemcpy(&temp2_ullong, mem2, sizeof(unsigned long long));
+
+    /* -d and !-p */
+    if (opts->delta_bool && !opts->percent_bool) {
+        if (PDIFF(temp1_ullong,temp2_ullong) > (unsigned long long) opts->delta) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULLI_FORMAT, temp1_ullong, temp2_ullong, PDIFF(temp1_ullong, temp2_ullong));
             }
-            mem1 += sizeof(unsigned long long);
-            mem2 += sizeof(unsigned long long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* !-d and -p */
-    else if (!opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ullong, mem1, sizeof(unsigned long long));
-            HDmemcpy(&temp2_ullong, mem2, sizeof(unsigned long long));
-
-            ull2float(temp1_ullong, &f1);
-            ull2float(temp2_ullong, &f2);
-            PER(f1, f2);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULLI_FORMAT_P_NOTCOMP,temp1_ullong,temp2_ullong,PDIFF(temp1_ullong,temp2_ullong));
-                }
-                nfound++;
+    else if (!opts->delta_bool && opts->percent_bool) {
+        ull2float(temp1_ullong, &f1);
+        ull2float(temp2_ullong, &f2);
+        PER(f1, f2);
+
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULLI_FORMAT_P_NOTCOMP, temp1_ullong, temp2_ullong, PDIFF(temp1_ullong, temp2_ullong));
             }
-            else if (per > opts->percent) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULLI_FORMAT_P,temp1_ullong,temp2_ullong,PDIFF(temp1_ullong,temp2_ullong),per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULLI_FORMAT_P, temp1_ullong, temp2_ullong, PDIFF(temp1_ullong,temp2_ullong), per);
             }
-            mem1 += sizeof(unsigned long long);
-            mem2 += sizeof(unsigned long long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     /* -d and -p */
-    else if (opts->d && opts->p) {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ullong, mem1, sizeof(unsigned long long));
-            HDmemcpy(&temp2_ullong, mem2, sizeof(unsigned long long));
-
-            ull2float(temp1_ullong, &f1);
-            ull2float(temp2_ullong, &f2);
-            PER(f1, f2);
-
-            if (not_comparable && !both_zero) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULLI_FORMAT_P_NOTCOMP,temp1_ullong,temp2_ullong,PDIFF(temp1_ullong,temp2_ullong));
-                }
-                nfound++;
+    else if (opts->delta_bool && opts->percent_bool) {
+        ull2float(temp1_ullong, &f1);
+        ull2float(temp2_ullong, &f2);
+        PER(f1, f2);
+
+        if (not_comparable && !both_zero) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULLI_FORMAT_P_NOTCOMP, temp1_ullong, temp2_ullong, PDIFF(temp1_ullong, temp2_ullong));
             }
-            else if (per > opts->percent
-                    && PDIFF(temp1_ullong,temp2_ullong) > (unsigned long long) opts->delta) {
-                if (print_data(opts)) {
-                    print_pos(ph, 1, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULLI_FORMAT_P,temp1_ullong,temp2_ullong,PDIFF(temp1_ullong,temp2_ullong),per);
-                }
-                nfound++;
+            nfound++;
+        }
+        else if (per > opts->percent && PDIFF(temp1_ullong,temp2_ullong) > (unsigned long long) opts->delta) {
+            opts->print_percentage = 1;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULLI_FORMAT_P, temp1_ullong, temp2_ullong, PDIFF(temp1_ullong, temp2_ullong), per);
             }
-            mem1 += sizeof(unsigned long long);
-            mem2 += sizeof(unsigned long long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
+            nfound++;
         }
     }
     else {
-        for (i = 0; i < nelmts; i++) {
-            HDmemcpy(&temp1_ullong, mem1, sizeof(unsigned long long));
-            HDmemcpy(&temp2_ullong, mem2, sizeof(unsigned long long));
-
-            if (temp1_ullong != temp2_ullong) {
-                if (print_data(opts)) {
-                    print_pos(ph, 0, hyper_start + i, acc, pos, rank, dims, obj1, obj2);
-                    parallel_print(SPACES);
-                    parallel_print(ULLI_FORMAT,temp1_ullong,temp2_ullong,PDIFF(temp1_ullong,temp2_ullong));
-                }
-                nfound++;
+        if (temp1_ullong != temp2_ullong) {
+            opts->print_percentage = 0;
+            print_pos(opts, elem_idx, -1);
+            if (print_data(opts)) {
+                parallel_print(ULLI_FORMAT, temp1_ullong, temp2_ullong, PDIFF(temp1_ullong, temp2_ullong));
             }
-
-            mem1 += sizeof(unsigned long long);
-            mem2 += sizeof(unsigned long long);
-            if (opts->n && nfound >= opts->count)
-                return nfound;
-        } /* nelmts */
+            nfound++;
+        }
     }
 
+    H5TOOLS_ENDDEBUG(": %d zero:%d", nfound, both_zero);
     return nfound;
 }
 
@@ -4391,7 +3008,7 @@ static hbool_t equal_float(float value, float expected, diff_opt_t *opts) {
 static
 int print_data(diff_opt_t *opts)
 {
-    return ((opts->m_report || opts->m_verbose) && !opts->m_quiet) ? 1 : 0;
+    return ((opts->mode_report || opts->mode_verbose) && !opts->mode_quiet) ? 1 : 0;
 }
 
 /*-------------------------------------------------------------------------
@@ -4401,25 +3018,24 @@ int print_data(diff_opt_t *opts)
  *-------------------------------------------------------------------------
  */
 static
-void print_header(int pp, /* print percentage */
-        int rank, hsize_t *dims, const char *obj1, const char *obj2)
+void print_header(diff_opt_t *opts)
 {
     /* print header */
     parallel_print("%-16s", "size:");
-    print_dimensions(rank, dims);
+    print_dimensions(opts->rank, opts->dims);
     parallel_print("%-11s", "");
-    print_dimensions(rank, dims);
+    print_dimensions(opts->rank, opts->dims);
     parallel_print("\n");
 
-    if (pp) {
+    if (opts->print_percentage) {
         parallel_print("%-15s %-15s %-15s %-15s %-15s\n", "position",
-                (obj1 != NULL) ? obj1 : " ", (obj2 != NULL) ? obj2 : " ", "difference", "relative");
+                opts->obj_name[0], opts->obj_name[1], "difference", "relative");
         parallel_print(
                 "------------------------------------------------------------------------\n");
     }
     else {
         parallel_print("%-15s %-15s %-15s %-20s\n", "position",
-                (obj1 != NULL) ? obj1 : " ", (obj2 != NULL) ? obj2 : " ", "difference");
+                opts->obj_name[0], opts->obj_name[1], "difference");
         parallel_print(
                 "------------------------------------------------------------\n");
     }
@@ -4432,77 +3048,93 @@ void print_header(int pp, /* print percentage */
  *-------------------------------------------------------------------------
  */
 static
-void print_pos(int *ph, /* print header */
-        int pp, /* print percentage */
-        hsize_t curr_pos, hsize_t *acc, hsize_t *pos, int rank, hsize_t *dims,
-        const char *obj1, const char *obj2)
+void print_pos(diff_opt_t *opts, hsize_t idx, ssize_t u)
 {
-    int i;
-
-    /* print header */
-    if (*ph == 1) {
-        *ph = 0;
-
-        print_header(pp, rank, dims, obj1, obj2);
-    } /* end print header */
-
-    for (i = 0; i < rank; i++) {
-        pos[i] = curr_pos / acc[i];
-        curr_pos -= acc[i] * pos[i];
-    }
-    HDassert(curr_pos == 0);
+    int i,j;
+
+    H5TOOLS_START_DEBUG(" -- idx:%ld", idx);
+
+    if (print_data(opts)) {
+        /* print header */
+        if (opts->print_header == 1) {
+            opts->print_header = 0;
+
+            print_header(opts);
+        } /* end print header */
+
+        H5TOOLS_DEBUG("rank=%d", opts->rank);
+        if(opts->rank > 0) {
+            hsize_t curr_pos = idx;
+
+            parallel_print("[ ");
+            H5TOOLS_DEBUG("do calc_acc_pos[%ld] nelmts:%d - errstat:%d", i, opts->hs_nelmts, opts->err_stat);
+
+            if (opts->sset[0] != NULL) {
+                /* Subsetting is used - calculate total position */
+                hsize_t elmnt_cnt = 1;
+                hsize_t dim_cnt = 0; /* previous dim size */
+                hsize_t str_cnt = 0; /* previous dim stride */
+                hsize_t curr_idx = idx; /* calculated running position */
+                hsize_t str_idx = 0;
+                hsize_t blk_idx = 0;
+                hsize_t cnt_idx = 0;
+                hsize_t hs_idx = 0;
+                j = opts->rank-1;
+                do {
+                    cnt_idx = opts->sset[0]->count.data[j]; /* Count value for current dim */
+                    H5TOOLS_DEBUG("... sset loop:%d with curr_pos:%ld (curr_idx:%ld) - count:%ld", j, curr_pos, curr_idx, cnt_idx);
+                    blk_idx = opts->sset[0]->block.data[j]; /* Block value for current dim */
+                    H5TOOLS_DEBUG("... sset loop:%d with curr_pos:%ld (curr_idx:%ld) - block:%ld", j, curr_pos, curr_idx, blk_idx);
+                    hs_idx = cnt_idx * blk_idx; /* hyperslab area value for current dim */
+                    H5TOOLS_DEBUG("... sset loop:%d with curr_pos:%ld (curr_idx:%ld) - hs:%ld", j, curr_pos, curr_idx, hs_idx);
+                    str_idx = opts->sset[0]->stride.data[j]; /* Stride value for current dim */
+                    H5TOOLS_DEBUG("... sset loop:%d with curr_pos:%ld (curr_idx:%ld) - stride:%ld", j, curr_pos, curr_idx, str_idx);
+                    elmnt_cnt *= opts->dims[j]; /* Total number of elements in dimension */
+                    H5TOOLS_DEBUG("... sset loop:%d with elmnt_cnt:%ld", j, elmnt_cnt);
+                    if (str_idx > blk_idx)
+                        curr_idx += dim_cnt * (str_idx - blk_idx); /* */
+                    else if (curr_idx >= hs_idx)
+                        curr_idx += dim_cnt * str_cnt;
+                    H5TOOLS_DEBUG("... sset loop:%d with idx:%ld (curr_idx:%ld) - stride:%ld", j, idx, curr_idx, str_idx);
+                    dim_cnt = elmnt_cnt; /* */
+                    if (str_idx > blk_idx)
+                        str_cnt = str_idx - blk_idx; /* */
+                    else
+                        str_cnt = str_idx; /* */
+                    H5TOOLS_DEBUG("... sset loop:%d with dim_cnt:%ld - str_cnt:%ld", j, dim_cnt, str_cnt);
+                    j--;
+                } while (curr_idx >= elmnt_cnt && j >= 0);
+                curr_pos = curr_idx; /* New current position */
+                H5TOOLS_DEBUG("pos loop:%d,%d with  elmnt_cnt:%ld - curr_pos:%ld", i, j, elmnt_cnt, curr_pos);
+            } /* if (opts->sset[0] != NULL) */
+            /*
+             * Calculate the number of elements represented by a unit change in a
+             * certain index position.
+             */
+            calc_acc_pos(opts->rank, curr_pos, opts->acc, opts->pos);
 
-    if (rank > 0) {
-        parallel_print("[ ");
-        for (i = 0; i < rank; i++) {
-            parallel_print(HSIZE_T_FORMAT, (unsigned long long)pos[i]);
-            parallel_print(" ");
+            for (i = 0; i < opts->rank; i++) {
+                H5TOOLS_DEBUG("pos loop:%d with opts->pos=%ld opts->sm_pos=%ld", i, opts->pos[i], opts->sm_pos[i]);
+                opts->pos[i] += (unsigned long) opts->sm_pos[i];
+                H5TOOLS_DEBUG("pos loop:%d with opts->pos=%ld", i, opts->pos[i]);
+                parallel_print(HSIZE_T_FORMAT, (unsigned long long)opts->pos[i]);
+                parallel_print(" ");
+            }
+            parallel_print("]");
         }
-        parallel_print("]");
-    }
-    else
-        parallel_print("      ");
-}
-
-/*-------------------------------------------------------------------------
- * Function: print_char_pos
- *
- * Purpose:  print character position in string
- *-------------------------------------------------------------------------
- */
-static
-void print_char_pos(int *ph, /* print header */
-        int pp, /* print percentage */
-        hsize_t curr_pos, size_t u, hsize_t *acc, hsize_t *pos, int rank, hsize_t *dims,
-        const char *obj1, const char *obj2)
-{
-    int i;
-
-    /* print header */
-    if (*ph == 1) {
-        *ph = 0;
-
-        print_header(pp, rank, dims, obj1, obj2);
-    } /* end print header */
-
-    for (i = 0; i < rank; i++) {
-        pos[i] = curr_pos / acc[i];
-        curr_pos -= acc[i] * pos[i];
-    }
-    HDassert(curr_pos == 0);
-
-    parallel_print("[ ");
-    if (rank > 0) {
-        for (i = 0; i < rank; i++) {
-            parallel_print(HSIZE_T_FORMAT, (unsigned long long)pos[i]);
-            parallel_print(" ");
+        else {
+            if (u >= 0) {
+                parallel_print("[ ");
+                parallel_print("%zu", u);
+                parallel_print("]");
+            }
+            else
+                parallel_print("      ");
         }
-
+        parallel_print(SPACES);
     }
-    else
-        parallel_print("%zu", u);
 
-    parallel_print("]");
+    H5TOOLS_ENDDEBUG("");
 }
 
 /*-------------------------------------------------------------------------
diff --git a/tools/lib/h5diff_attr.c b/tools/lib/h5diff_attr.c
index 731fc54..3b5f6cc 100644
--- a/tools/lib/h5diff_attr.c
+++ b/tools/lib/h5diff_attr.c
@@ -137,7 +137,7 @@ static void table_attr_mark_exist(unsigned *exist, char *name, table_attrs_t *ta
  * Parameter:
  *  table_out [OUT] : return the list
  *------------------------------------------------------------------------*/
-static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t ** table_out,  diff_opt_t *opts)
+static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t ** table_out, diff_opt_t *opts)
 {
     table_attrs_t *table_lp = NULL;
     H5O_info_t     oinfo1, oinfo2;    /* Object info */
@@ -154,10 +154,14 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
 
     H5TOOLS_START_DEBUG(" - errstat:%d", opts->err_stat);
 
-    if(H5Oget_info2(loc1_id, &oinfo1, H5O_INFO_NUM_ATTRS) < 0)
+    if(H5Oget_info2(loc1_id, &oinfo1, H5O_INFO_NUM_ATTRS) < 0) {
         H5TOOLS_GOTO_ERROR(FAIL, "H5Oget_info first object failed");
-    if(H5Oget_info2(loc2_id, &oinfo2, H5O_INFO_NUM_ATTRS) < 0)
+    }
+    H5TOOLS_DEBUG("H5Oget_info3 loc1id=%d", oinfo1.num_attrs);
+    if(H5Oget_info2(loc2_id, &oinfo2, H5O_INFO_NUM_ATTRS) < 0) {
         H5TOOLS_GOTO_ERROR(FAIL, "H5Oget_info second object failed");
+    }
+    H5TOOLS_DEBUG("H5Oget_info3 loc2id=%d", oinfo2.num_attrs);
 
     table_attrs_init(&table_lp);
     if (table_lp == NULL)
@@ -167,8 +171,8 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
      * build the list
      */
     while(curr1 < oinfo1.num_attrs && curr2 < oinfo2.num_attrs) {
-        H5TOOLS_DEBUG("build_match_list_attrs 1: %ld - %ld", curr1, oinfo1.num_attrs);
-        H5TOOLS_DEBUG("build_match_list_attrs 2: %ld - %ld", curr2, oinfo2.num_attrs);
+        H5TOOLS_DEBUG("list_attrs 1: %ld - %ld", curr1, oinfo1.num_attrs);
+        H5TOOLS_DEBUG("list_attrs 2: %ld - %ld", curr2, oinfo2.num_attrs);
 
         /*------------------
         * open attribute1 */
@@ -222,7 +226,7 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
     infile[0] = 1;
     infile[1] = 0;
     while(curr1 < oinfo1.num_attrs) {
-        H5TOOLS_DEBUG("build_match_list_attrs 1: %ld - %ld", curr1, oinfo1.num_attrs);
+        H5TOOLS_DEBUG("list_attrs 1: %ld - %ld", curr1, oinfo1.num_attrs);
 
         /*------------------
         * open attribute1 */
@@ -231,7 +235,7 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
         /* get name */
         if(H5Aget_name(attr1_id, (size_t)ATTR_NAME_MAX, name1) < 0)
             H5TOOLS_GOTO_ERROR(FAIL, "H5Aget_name first attribute failed");
-        H5TOOLS_DEBUG("build_match_list_attrs #1 name - %s", name1);
+        H5TOOLS_DEBUG("list_attrs 1 name - %s", name1);
 
         table_attr_mark_exist(infile, name1, table_lp);
         table_lp->nattrs_only1++;
@@ -246,7 +250,7 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
     infile[0] = 0;
     infile[1] = 1;
     while(curr2 < oinfo2.num_attrs) {
-        H5TOOLS_DEBUG("build_match_list_attrs 2: %ld - %ld", curr2, oinfo2.num_attrs);
+        H5TOOLS_DEBUG("list_attrs 2: %ld - %ld", curr2, oinfo2.num_attrs);
         /*------------------
         * open attribute2 */
         if((attr2_id = H5Aopen_by_idx(loc2_id, ".", H5_INDEX_NAME, H5_ITER_INC, (hsize_t)curr2, H5P_DEFAULT, H5P_DEFAULT)) < 0)
@@ -254,7 +258,7 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
         /* get name */
         if(H5Aget_name(attr2_id, (size_t)ATTR_NAME_MAX, name2) < 0)
             H5TOOLS_GOTO_ERROR(FAIL, "H5Aget_name second attribute failed");
-        H5TOOLS_DEBUG("build_match_list_attrs #2 name - %s", name2);
+        H5TOOLS_DEBUG("list_attrs 2 name - %s", name2);
 
         table_attr_mark_exist(infile, name2, table_lp);
         table_lp->nattrs_only2++;
@@ -268,7 +272,7 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
     /*------------------------------------------------------
      * print the list
      */
-    if(opts->m_verbose_level == 2) {
+    if(opts->mode_verbose_level == 2) {
         /* if '-v2' is detected */
         parallel_print("   obj1   obj2\n");
         parallel_print(" --------------------------------------\n");
@@ -280,7 +284,7 @@ static herr_t build_match_list_attrs(hid_t loc1_id, hid_t loc2_id, table_attrs_t
         } /* end for */
     }
 
-    if(opts->m_verbose_level >= 1)
+    if(opts->mode_verbose_level >= 1)
         parallel_print("Attributes status:  %d common, %d only in obj1, %d only in obj2\n",
                 table_lp->nattrs - table_lp->nattrs_only1 - table_lp->nattrs_only2,
                 table_lp->nattrs_only1, table_lp->nattrs_only2);
@@ -309,7 +313,8 @@ done:
  *-------------------------------------------------------------------------
  */
 
-hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id, const char *name1, const char *name2, const char *path1, const char *path2, diff_opt_t *opts)
+hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id,
+        const char *name1, const char *name2, const char *path1, const char *path2, diff_opt_t *opts)
 {
     hid_t      space1_id = H5I_INVALID_HID;    /* space ID */
     hid_t      space2_id = H5I_INVALID_HID;    /* space ID */
@@ -323,19 +328,15 @@ hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id, const char *name1, const
     void      *buf2 = NULL;       /* data buffer */
     hbool_t    buf1hasdata = FALSE;    /* buffer has data */
     hbool_t    buf2hasdata = FALSE;    /* buffer has data */
-    hsize_t    nelmts1;           /* number of elements in dataset */
     int        rank1;             /* rank of dataset */
     int        rank2;             /* rank of dataset */
     hsize_t    dims1[H5S_MAX_RANK];    /* dimensions of dataset */
     hsize_t    dims2[H5S_MAX_RANK];    /* dimensions of dataset */
-    char       np1[512];
-    char       np2[512];
     hsize_t    nfound = 0;
     int        j;
     diff_err_t ret_value = opts->err_stat;
 
     H5TOOLS_START_DEBUG(" - errstat:%d", opts->err_stat);
-
     /* get the datatypes  */
     if((ftype1_id = H5Aget_type(attr1_id)) < 0)
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Aget_type first attribute failed");
@@ -367,11 +368,32 @@ hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id, const char *name1, const
     * check for comparable TYPE and SPACE
     *----------------------------------------------------------------------
     */
-    H5TOOLS_DEBUG("diff_attr_data check for comparable TYPE and SPACE");
+    H5TOOLS_DEBUG("Check for comparable TYPE and SPACE");
+
+    H5TOOLS_DEBUG("attr_names: %s - %s", name1, name2);
+    if (name1) {
+        j = (int)HDstrlen(name1);
+        H5TOOLS_DEBUG("attr1_name: %s - %d", name1, j);
+        if (j > 0) {
+            opts->obj_name[0] = (char *)HDcalloc((size_t)j + 1, sizeof(char));
+            HDstrncpy(opts->obj_name[0], name1, (size_t)j);
+            opts->obj_name[0][j] = '\0';
+        }
+    }
+    if (name2) {
+        j = (int)HDstrlen(name2);
+        H5TOOLS_DEBUG("attr2_name: %s - %d", name2, j);
+        if (j > 0) {
+            opts->obj_name[1] = (char *)HDcalloc((size_t)j + 1, sizeof(char));
+            HDstrncpy(opts->obj_name[1], name2, (size_t)j);
+            opts->obj_name[1][j] = '\0';
+        }
+    }
+    H5TOOLS_DEBUG("attr_names: %s - %s", opts->obj_name[0], opts->obj_name[1]);
 
     /* pass dims1 and dims2 for maxdims as well since attribute's maxdims
     * are always same */
-    if(diff_can_type(ftype1_id, ftype2_id, rank1, rank2, dims1, dims2, dims1, dims2, name1, name2, opts, 0) == 1) {
+    if(diff_can_type(ftype1_id, ftype2_id, rank1, rank2, dims1, dims2, dims1, dims2, opts, 0) == 1) {
         /*-----------------------------------------------------------------
         * "upgrade" the smaller memory size
         *------------------------------------------------------------------
@@ -379,17 +401,26 @@ hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id, const char *name1, const
         if(FAIL == match_up_memsize(ftype1_id, ftype2_id, &mtype1_id, &mtype2_id, &msize1, &msize2))
             H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "match_up_memsize failed");
 
-        H5TOOLS_DEBUG("diff_attr_data read");
+        H5TOOLS_DEBUG("initialize read");
         /*---------------------------------------------------------------------
-        * read
+        * initialize diff_opt_t structure for dimensions
         *----------------------------------------------------------------------
         */
-        nelmts1 = 1;
-        for(j = 0; j < rank1; j++)
-            nelmts1 *= dims1[j];
+        opts->nelmts = 1;
+        for(j = 0; j < rank1; j++) {
+            opts->dims[j] = dims1[j];
+            opts->nelmts *= dims1[j];
+        }
+        opts->rank = rank1;
+        init_acc_pos(opts->rank, opts->dims, opts->acc, opts->pos, opts->p_min_idx);
 
-        buf1 = (void *)HDcalloc((size_t)(nelmts1), msize1);
-        buf2 = (void *)HDcalloc((size_t)(nelmts1), msize2);
+        /*---------------------------------------------------------------------
+        * read
+        *----------------------------------------------------------------------
+        */
+        buf1 = (void *)HDcalloc((size_t)(opts->nelmts), msize1);
+        buf2 = (void *)HDcalloc((size_t)(opts->nelmts), msize2);
+        H5TOOLS_DEBUG("attr buffer size %ld * %ld", opts->nelmts, msize1);
         if(buf1 == NULL || buf2 == NULL) {
             parallel_print("cannot read into memory\n");
             H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "buffer allocation failed");
@@ -400,6 +431,7 @@ hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id, const char *name1, const
         }
         else
             buf1hasdata = TRUE;
+        H5TOOLS_DEBUG("attr H5Aread 1");
 
         if(H5Aread(attr2_id, mtype2_id, buf2) < 0) {
             parallel_print("Failed reading attribute2 %s\n", name2);
@@ -407,49 +439,84 @@ hsize_t diff_attr_data(hid_t attr1_id, hid_t attr2_id, const char *name1, const
         }
         else
             buf2hasdata = TRUE;
+        H5TOOLS_DEBUG("attr H5Aread 2");
 
         /* format output string */
-        HDsnprintf(np1, sizeof(np1), "%s of <%s>", name1, path1);
-        HDsnprintf(np2, sizeof(np1), "%s of <%s>", name2, path2);
+        if (opts->obj_name[0] != NULL)
+             HDfree(opts->obj_name[0]);
+        opts->obj_name[0] = NULL;
+        if (opts->obj_name[1] != NULL)
+             HDfree(opts->obj_name[1]);
+        opts->obj_name[1] = NULL;
+
+        H5TOOLS_DEBUG("attr_names: %s - %s : %s - %s", name1, name2, path1, path2);
+        if (name1) {
+            j = (int)HDstrlen(name1) + (int)HDstrlen(path1) + 7;
+            H5TOOLS_DEBUG("attr1_name: %s - %d", name1, j);
+            if (j > 0) {
+                opts->obj_name[0] = (char *)HDcalloc((size_t)j + 1, sizeof(char));
+                HDsnprintf(opts->obj_name[0], j, "%s of <%s>", name1, path1);
+                opts->obj_name[0][j] = '\0';
+            }
+        }
+        if (name2) {
+            j = (int)HDstrlen(name2) + (int)HDstrlen(path2) + 7;
+            H5TOOLS_DEBUG("attr2_name: %s - %d", name2, j);
+            if (j > 0) {
+                opts->obj_name[1] = (char *)HDcalloc((size_t)j + 1, sizeof(char));
+                HDsnprintf(opts->obj_name[1], j, "%s of <%s>", name2, path2);
+                opts->obj_name[1][j] = '\0';
+            }
+        }
 
         /*---------------------------------------------------------------------
         * array compare
         *----------------------------------------------------------------------
         */
-        H5TOOLS_DEBUG("diff_attr_data array compare %s - %s", name1, name1);
+        H5TOOLS_DEBUG("array compare %s - %s", opts->obj_name[0], opts->obj_name[1]);
+
+        opts->hs_nelmts = opts->nelmts;
+        opts->m_tid = mtype1_id;
+
+        /* initialize the current stripmine position; this is necessary to print the array indices */
+        for (j = 0; j < opts->rank; j++)
+            opts->sm_pos[j] = (hsize_t)0;
 
         /* always print name */
         /* verbose (-v) and report (-r) mode */
-        if(opts->m_verbose || opts->m_report) {
-            do_print_attrname("attribute", np1, np2);
+        if(opts->mode_verbose || opts->mode_report) {
+            do_print_attrname("attribute", opts->obj_name[0], opts->obj_name[1]);
 
-            nfound = diff_array(buf1, buf2, nelmts1, (hsize_t) 0, rank1,
-                    dims1, opts, np1, np2, mtype1_id, attr1_id, attr2_id);
+            nfound = diff_array(buf1, buf2, opts, attr1_id, attr2_id);
             print_found(nfound);
         }
         /* quiet mode (-q), just count differences */
-        else if(opts->m_quiet) {
-            nfound = diff_array(buf1, buf2, nelmts1, (hsize_t) 0, rank1,
-                    dims1, opts, np1, np2, mtype1_id, attr1_id, attr2_id);
+        else if(opts->mode_quiet) {
+            nfound = diff_array(buf1, buf2, opts, attr1_id, attr2_id);
         }
         /* the rest (-c, none, ...) */
         else {
-            nfound = diff_array(buf1, buf2, nelmts1, (hsize_t) 0, rank1,
-                    dims1, opts, np1, np2, mtype1_id, attr1_id, attr2_id);
+            nfound = diff_array(buf1, buf2, opts, attr1_id, attr2_id);
 
             /* print info if compatible and difference found */
             if (nfound) {
-                do_print_attrname("attribute", np1, np2);
+                do_print_attrname("attribute", opts->obj_name[0], opts->obj_name[1]);
                 print_found(nfound);
             } /* end if */
         } /* end else */
     }
-    H5TOOLS_DEBUG("diff_attr_data check for comparable TYPE and SPACE complete nfound:%d - errstat:%d", nfound, opts->err_stat);
+    H5TOOLS_DEBUG("check for comparable TYPE and SPACE complete nfound:%d - errstat:%d", nfound, opts->err_stat);
 
     /*----------------------------------------------------------------------
     * close
     *----------------------------------------------------------------------
     */
+   if (opts->obj_name[0] != NULL)
+        HDfree(opts->obj_name[0]);
+   opts->obj_name[0] = NULL;
+   if (opts->obj_name[1] != NULL)
+        HDfree(opts->obj_name[1]);
+   opts->obj_name[1] = NULL;
 
     /* Free buf1 and buf2, check both VLEN-data VLEN-string to reclaim any
     * VLEN memory first */
@@ -527,28 +594,32 @@ hsize_t diff_attr(hid_t loc1_id, hid_t loc2_id, const char *path1, const char *p
     unsigned       u;                 /* Local index variable */
     hsize_t        nfound = 0;
     hsize_t        nfound_total = 0;
+    diff_opt_t attr_opts;
     diff_err_t     ret_value = opts->err_stat;
 
     H5TOOLS_START_DEBUG(" - errstat:%d", opts->err_stat);
+    attr_opts = *opts;
+    attr_opts.obj_name[0] = NULL;
+    attr_opts.obj_name[1] = NULL;
 
-    if(build_match_list_attrs(loc1_id, loc2_id, &match_list_attrs, opts) < 0) {
+    if(build_match_list_attrs(loc1_id, loc2_id, &match_list_attrs, &attr_opts) < 0) {
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "build_match_list_attrs failed");
     }
-    H5TOOLS_DEBUG("build_match_list_attrs - errstat:%d", opts->err_stat);
+    H5TOOLS_DEBUG("check match_list_attrs - opts->contents:%d - errstat:%d", attr_opts.contents, attr_opts.err_stat);
 
     /* if detect any unique extra attr */
     if(match_list_attrs->nattrs_only1 || match_list_attrs->nattrs_only2) {
-        H5TOOLS_DEBUG("diff_attr attributes only in one file");
+        H5TOOLS_DEBUG("attributes only in one file");
         /* exit will be 1 */
-        opts->contents = 0;
+        attr_opts.contents = 0;
     }
-    H5TOOLS_DEBUG("match_list_attrs info - errstat:%d", opts->err_stat);
+    H5TOOLS_DEBUG("match_list_attrs info - opts->contents:%d", attr_opts.contents);
 
     for(u = 0; u < (unsigned)match_list_attrs->nattrs; u++) {
-        H5TOOLS_DEBUG("match_list_attrs loop[%d] - errstat:%d", u, opts->err_stat);
+        H5TOOLS_DEBUG("match_list_attrs loop[%d] - errstat:%d", u, attr_opts.err_stat);
         if((match_list_attrs->attrs[u].exist[0]) && (match_list_attrs->attrs[u].exist[1])) {
             name1 = name2 = match_list_attrs->attrs[u].name;
-            H5TOOLS_DEBUG("diff_attr name - %s", name1);
+            H5TOOLS_DEBUG("name - %s", name1);
 
             /*--------------
             * attribute 1 */
@@ -560,8 +631,8 @@ hsize_t diff_attr(hid_t loc1_id, hid_t loc2_id, const char *path1, const char *p
             if((attr2_id = H5Aopen(loc2_id, name2, H5P_DEFAULT)) < 0)
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Aopen second attribute failed");
 
-            H5TOOLS_DEBUG("diff_attr got attributes");
-            nfound = diff_attr_data(attr1_id, attr2_id, name1, name2, path1, path2, opts);
+            H5TOOLS_DEBUG("got attributes");
+            nfound = diff_attr_data(attr1_id, attr2_id, name1, name2, path1, path2, &attr_opts);
             if(H5Aclose(attr1_id) < 0)
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Aget_type first attribute failed");
             if(H5Aclose(attr2_id) < 0)
@@ -572,7 +643,10 @@ hsize_t diff_attr(hid_t loc1_id, hid_t loc2_id, const char *path1, const char *p
     } /* u */
 
 done:
-    opts->err_stat = opts->err_stat | ret_value;
+    opts->print_header = attr_opts.print_header;
+    opts->contents = attr_opts.contents;
+    opts->not_cmp = attr_opts.not_cmp;
+    opts->err_stat = attr_opts.err_stat | ret_value;
 
     H5E_BEGIN_TRY {
         table_attrs_free(match_list_attrs);
diff --git a/tools/lib/h5diff_dset.c b/tools/lib/h5diff_dset.c
index 7a2342b..79884fa 100644
--- a/tools/lib/h5diff_dset.c
+++ b/tools/lib/h5diff_dset.c
@@ -27,7 +27,8 @@
  * Return: Number of differences found
  *-------------------------------------------------------------------------
  */
-hsize_t diff_dataset(hid_t file1_id, hid_t file2_id, const char *obj1_name, const char *obj2_name, diff_opt_t *opts)
+hsize_t
+diff_dataset(hid_t file1_id, hid_t file2_id, const char *obj1_name, const char *obj2_name, diff_opt_t *opts)
 {
     int        status = -1;
     hid_t      did1 = H5I_INVALID_HID;
@@ -35,9 +36,15 @@ hsize_t diff_dataset(hid_t file1_id, hid_t file2_id, const char *obj1_name, cons
     hid_t      dcpl1 = H5I_INVALID_HID;
     hid_t      dcpl2 = H5I_INVALID_HID;
     hsize_t    nfound = 0;
+    diff_opt_t diff_opts;
     diff_err_t ret_value = opts->err_stat;
 
     H5TOOLS_START_DEBUG(" - errstat:%d", opts->err_stat);
+    diff_opts = *opts;
+    diff_opts.obj_name[0] = NULL;
+    diff_opts.obj_name[1] = NULL;
+
+    H5TOOLS_DEBUG("obj_names: %s - %s", obj1_name, obj2_name);
     /*-------------------------------------------------------------------------
      * open the handles
      *-------------------------------------------------------------------------
@@ -64,20 +71,22 @@ hsize_t diff_dataset(hid_t file1_id, hid_t file2_id, const char *obj1_name, cons
      * 2) the internal filters might be turned off
      *-------------------------------------------------------------------------
      */
-    H5TOOLS_DEBUG("diff_dataset h5tools_canreadf then diff_datasetid");
-    if ((status = h5tools_canreadf((opts->m_verbose ? obj1_name : NULL), dcpl1) == 1) &&
-            (status = h5tools_canreadf((opts->m_verbose ? obj2_name : NULL), dcpl2) == 1))
-        nfound = diff_datasetid(did1, did2, obj1_name, obj2_name, opts);
+    H5TOOLS_DEBUG("h5tools_canreadf then diff_datasetid");
+    if ((status = h5tools_canreadf((opts->mode_verbose ? obj1_name : NULL), dcpl1) == 1) &&
+            (status = h5tools_canreadf((opts->mode_verbose ? obj2_name : NULL), dcpl2) == 1))
+        nfound = diff_datasetid(did1, did2, obj1_name, obj2_name, &diff_opts);
     else if (status < 0) {
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "h5tools_canreadf failed");
     }
     else {
         ret_value = 1;
-        opts->not_cmp = 1;
+        diff_opts.not_cmp = 1;
     }
 
 done:
-    opts->err_stat = opts->err_stat | ret_value;
+    opts->print_header = diff_opts.print_header;
+    opts->not_cmp = diff_opts.not_cmp;
+    opts->err_stat = diff_opts.err_stat | ret_value;
 
     /* disable error reporting */
     H5E_BEGIN_TRY {
@@ -143,36 +152,31 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char *obj2_name, diff_opt_t *opts)
+hsize_t
+diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char *obj2_name, diff_opt_t *opts)
 {
     hid_t      sid1 = H5I_INVALID_HID;
     hid_t      sid2 = H5I_INVALID_HID;
     hid_t      f_tid1 = H5I_INVALID_HID;
     hid_t      f_tid2 = H5I_INVALID_HID;
-    hid_t      dam_tid = H5I_INVALID_HID;             /* m_tid for diff_array function */
     hid_t      m_tid1 = H5I_INVALID_HID;
     hid_t      m_tid2 = H5I_INVALID_HID;
     hid_t      dcpl1 = H5I_INVALID_HID;
     hid_t      dcpl2 = H5I_INVALID_HID;
     H5D_layout_t     stl1 = -1;
     H5D_layout_t     stl2 = -1;
-    size_t     dam_size;                /* m_size for diff_array function */
     size_t     m_size1;
     size_t     m_size2;
     H5T_sign_t sign1;
     H5T_sign_t sign2;
     int        rank1;
     int        rank2;
-    hsize_t    danelmts;                /* nelmts for diff_array function */
     hsize_t    nelmts1;
     hsize_t    nelmts2;
-    hsize_t    *dadims;                 /* dims for diff_array function */
     hsize_t    dims1[H5S_MAX_RANK];
     hsize_t    dims2[H5S_MAX_RANK];
     hsize_t    maxdim1[H5S_MAX_RANK];
     hsize_t    maxdim2[H5S_MAX_RANK];
-    const char *name1 = NULL;           /* relative names */
-    const char *name2 = NULL;
     hsize_t    storage_size1;
     hsize_t    storage_size2;
     hsize_t    nfound = 0;              /* number of differences found */
@@ -181,9 +185,10 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
     void       *buf2 = NULL;
     void       *sm_buf1 = NULL;
     void       *sm_buf2 = NULL;
-    hid_t      sm_space = H5I_INVALID_HID;           /*stripmine data space */
+    hid_t      sm_space1 = H5I_INVALID_HID;           /*stripmine data space */
+    hid_t      sm_space2 = H5I_INVALID_HID;           /*stripmine data space */
     size_t     need;                    /* bytes needed for malloc */
-    int        i;
+    int        i, j;
     unsigned int  vl_data1 = 0;          /*contains VL datatypes */
     unsigned int  vl_data2 = 0;          /*contains VL datatypes */
     diff_err_t    ret_value = opts->err_stat;
@@ -233,13 +238,15 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
      */
     if((dcpl1 = H5Dget_create_plist(did1)) < 0)
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dget_create_plist failed");
-    if((dcpl2 = H5Dget_create_plist(did2)) < 0)
-        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dget_create_plist failed");
-
     if((stl1 = H5Pget_layout(dcpl1)) < 0)
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Pget_layout failed");
+    H5Pclose(dcpl1);
+
+    if((dcpl2 = H5Dget_create_plist(did2)) < 0)
+        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dget_create_plist failed");
     if((stl2 = H5Pget_layout(dcpl2)) < 0)
         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Pget_layout failed");
+    H5Pclose(dcpl2);
 
     /*-------------------------------------------------------------------------
      * check for empty datasets
@@ -253,27 +260,48 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
 
     if(storage_size1 == 0 || storage_size2 == 0) {
         if(stl1 == H5D_VIRTUAL || stl2 == H5D_VIRTUAL) {
-            if((opts->m_verbose||opts->m_list_not_cmp) && obj1_name && obj2_name)
+            if((opts->mode_verbose||opts->mode_list_not_cmp) && obj1_name && obj2_name)
                 parallel_print("Warning: <%s> or <%s> is a virtual dataset\n", obj1_name, obj2_name);
         }
         else {
-            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name)
+            if((opts->mode_verbose || opts->mode_list_not_cmp) && obj1_name && obj2_name)
                 parallel_print("Not comparable: <%s> or <%s> is an empty dataset\n", obj1_name, obj2_name);
             can_compare = 0;
             opts->not_cmp = 1;
         }
     }
 
+    H5TOOLS_DEBUG("obj_names: %s - %s", obj1_name, obj2_name);
+    opts->obj_name[0] = NULL;
+    if (obj1_name) {
+        j = (int)HDstrlen(obj1_name);
+        H5TOOLS_DEBUG("obj1_name: %s - %d", obj1_name, j);
+        if (j > 0) {
+            opts->obj_name[0] = (char *)HDcalloc((size_t)j + 1, sizeof(char));
+            HDstrncpy(opts->obj_name[0], obj1_name, (size_t)j );
+            opts->obj_name[0][j] = '\0';
+        }
+    }
+
+
+    opts->obj_name[1] = NULL;
+    if (obj2_name) {
+        j = (int)HDstrlen(obj2_name);
+        H5TOOLS_DEBUG("obj2_name: %s - %d", obj2_name, j);
+        if (j > 0) {
+            opts->obj_name[1] = (char *)HDcalloc((size_t)j + 1, sizeof(char));
+            HDstrncpy(opts->obj_name[1], obj2_name, (size_t)j);
+            opts->obj_name[1][j] = '\0';
+        }
+    }
+
     /*-------------------------------------------------------------------------
      * check for comparable TYPE and SPACE
      *-------------------------------------------------------------------------
      */
-    if (diff_can_type(f_tid1, f_tid2, rank1, rank2,
-            dims1, dims2, maxdim1, maxdim2,
-            obj1_name, obj2_name,
-            opts, 0) != 1)
+    if (diff_can_type(f_tid1, f_tid2, rank1, rank2, dims1, dims2, maxdim1, maxdim2, opts, 0) != 1)
         can_compare = 0;
-    H5TOOLS_DEBUG("diff_can_type - errstat:%d", opts->err_stat);
+    H5TOOLS_DEBUG("diff_can_type returned errstat:%d", opts->err_stat);
 
     /*-------------------------------------------------------------------------
      * memory type and sizes
@@ -281,10 +309,10 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
      */
     H5TOOLS_DEBUG("check for memory type and sizes");
     if((m_tid1 = H5Tget_native_type(f_tid1, H5T_DIR_DEFAULT)) < 0)
-        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Tget_native_type failed");
+        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Tget_native_type first ftype failed");
 
     if((m_tid2 = H5Tget_native_type(f_tid2, H5T_DIR_DEFAULT)) < 0)
-        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Tget_native_type failed");
+        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Tget_native_type second ftype failed");
 
     m_size1 = H5Tget_size(m_tid1);
     m_size2 = H5Tget_size(m_tid2);
@@ -300,7 +328,7 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
         sign2 = H5Tget_sign(m_tid2);
         if(sign1 != sign2) {
             H5TOOLS_DEBUG("sign1 != sign2");
-            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
+            if((opts->mode_verbose || opts->mode_list_not_cmp) && obj1_name && obj2_name) {
                 parallel_print("Not comparable: <%s> has sign %s ", obj1_name, get_sign(sign1));
                 parallel_print("and <%s> has sign %s\n", obj2_name, get_sign(sign2));
             }
@@ -348,41 +376,56 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
              *------------------------------------------------------------------
              */
             H5TOOLS_DEBUG("NOT H5T_ARRAY, upgrade the smaller memory size?");
-            if (FAIL == match_up_memsize (f_tid1, f_tid2,
-                                        &m_tid1, &m_tid2,
-                                        &m_size1, &m_size2))
+            if (FAIL == match_up_memsize (f_tid1, f_tid2, &m_tid1, &m_tid2, &m_size1, &m_size2))
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "match_up_memsize failed");
             H5TOOLS_DEBUG("m_size: %ld - %ld", m_size1, m_size2);
-            dadims = dims1;
-            dam_size = m_size1;
-            dam_tid = m_tid1;
-            danelmts = nelmts1;
+            opts->rank = rank1;
+            for(i = 0; i < rank1; i++)
+                opts->dims[i] = dims1[i];
+            opts->m_size = m_size1;
+            opts->m_tid = m_tid1;
+            opts->nelmts = nelmts1;
             need = (size_t)(nelmts1 * m_size1);  /* bytes needed */
         }
         else {
             H5TOOLS_DEBUG("Array dims: %d - %d", dims1[0], dims2[0]);
             /* Compare the smallest array, but create the largest buffer */
             if(m_size1 <= m_size2) {
-                dadims = dims1;
-                dam_size = m_size1;
-                dam_tid = m_tid1;
-                danelmts = nelmts1;
+                opts->rank = rank1;
+                for(i = 0; i < rank1; i++)
+                    opts->dims[i] = dims1[i];
+                opts->m_size = m_size1;
+                opts->m_tid = m_tid1;
+                opts->nelmts = nelmts1;
                 need = (size_t)(nelmts2 * m_size2);  /* bytes needed */
             }
             else {
-                dadims = dims2;
-                dam_size = m_size2;
-                dam_tid = m_tid2;
-                danelmts = nelmts2;
+                opts->rank = rank2;
+                for(i = 0; i < rank2; i++)
+                    opts->dims[i] = dims2[i];
+                opts->m_size = m_size2;
+                opts->m_tid = m_tid2;
+                opts->nelmts = nelmts2;
                 need = (size_t)(nelmts1 * m_size1);  /* bytes needed */
             }
         }
+        opts->hs_nelmts = opts->nelmts;
+        H5TOOLS_DEBUG("need: %ld", need);
         /* print names */
+        H5TOOLS_DEBUG("obj_names: %s - %s", obj1_name, obj2_name);
+
+        if (opts->obj_name[0] != NULL)
+             HDfree(opts->obj_name[0]);
+        opts->obj_name[0] = NULL;
+        if (opts->obj_name[1] != NULL)
+             HDfree(opts->obj_name[1]);
+        opts->obj_name[1] = NULL;
+
         if(obj1_name)
-            name1 = diff_basename(obj1_name);
+            opts->obj_name[0] = HDstrdup(diff_basename(obj1_name));
         if(obj2_name)
-            name2 = diff_basename(obj2_name);
-        H5TOOLS_DEBUG("obj_names: %s - %s", name1, name2);
+            opts->obj_name[1] = HDstrdup(diff_basename(obj2_name));
+        H5TOOLS_DEBUG("obj_names: %s - %s", opts->obj_name[0], opts->obj_name[1]);
 
 
         H5TOOLS_DEBUG("read/compare");
@@ -395,7 +438,14 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
             buf2 = HDmalloc(need);
         } /* end if */
 
-        if(buf1 != NULL && buf2 != NULL) {
+        /* Assume entire data space to be printed */
+        init_acc_pos(opts->rank, opts->dims, opts->acc, opts->pos, opts->p_min_idx);
+
+        for(i = 0; i < opts->rank; i++) {
+            opts->p_max_idx[i] = opts->dims[i];
+        }
+
+        if(buf1 != NULL && buf2 != NULL && opts->sset[0] == NULL && opts->sset[1] == NULL) {
             H5TOOLS_DEBUG("buf1 != NULL && buf2 != NULL");
             H5TOOLS_DEBUG("H5Dread did1");
             if(H5Dread(did1, m_tid1, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf1) < 0)
@@ -404,10 +454,13 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
             if(H5Dread(did2, m_tid2, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf2) < 0)
                 H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dread failed");
 
+            /* initialize the current stripmine position; this is necessary to print the array indices */
+            for (j = 0; j < opts->rank; j++)
+                opts->sm_pos[j] = (hsize_t)0;
+
             /* array diff */
-            nfound = diff_array(buf1, buf2, danelmts, (hsize_t)0, rank1, dadims,
-                opts, name1, name2, dam_tid, did1, did2);
-            H5TOOLS_DEBUG("diff_array nfound:%d - errstat:%d", nfound, opts->err_stat);
+            nfound = diff_array(buf1, buf2, opts, did1, did2);
+            H5TOOLS_DEBUG("diff_array ret nfound:%d - errstat:%d", nfound, opts->err_stat);
 
             /* reclaim any VL memory, if necessary */
             H5TOOLS_DEBUG("check vl_data1:%d", vl_data1);
@@ -426,111 +479,369 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
             }
         } /* end if */
         else { /* possibly not enough memory, read/compare by hyperslabs */
-            size_t        p_type_nbytes = dam_size; /*size of memory type */
-            hsize_t       p_nelmts = danelmts;      /*total selected elmts */
-            hsize_t       elmtno;                  /*counter  */
-            int           carry;                   /*counter carry value */
+            hsize_t       elmtno;                   /* counter  */
+            int           carry;                    /* counter carry value */
 
             /* stripmine info */
-            hsize_t       sm_size[H5S_MAX_RANK];   /*stripmine size */
-            hsize_t       sm_nbytes;               /*bytes per stripmine */
-            hsize_t       sm_nelmts;               /*elements per stripmine*/
+            hsize_t       sm_size[H5S_MAX_RANK];    /* stripmine size */
+            hsize_t       sm_block[H5S_MAX_RANK];   /* stripmine block size  */
+            hsize_t       sm_nbytes;                /* bytes per stripmine */
+            hsize_t       sm_nelmts1;               /* elements per stripmine */
+            hsize_t       sm_nelmts2;               /* elements per stripmine */
+            hssize_t      ssm_nelmts;               /* elements temp */
 
             /* hyperslab info */
-            hsize_t       hs_offset[H5S_MAX_RANK]; /*starting offset */
-            hsize_t       hs_size[H5S_MAX_RANK];   /*size this pass */
-            hsize_t       hs_nelmts;               /*elements in request */
-            hsize_t       zero[8];                 /*vector of zeros */
+            hsize_t       hs_offset1[H5S_MAX_RANK]; /* starting offset */
+            hsize_t       hs_count1[H5S_MAX_RANK];  /* number of blocks */
+            hsize_t       hs_block1[H5S_MAX_RANK];  /* size of blocks */
+            hsize_t       hs_stride1[H5S_MAX_RANK]; /* stride */
+            hsize_t       hs_size1[H5S_MAX_RANK];   /* size this pass */
+            hsize_t       hs_offset2[H5S_MAX_RANK]; /* starting offset */
+            hsize_t       hs_count2[H5S_MAX_RANK];  /* number of blocks */
+            hsize_t       hs_block2[H5S_MAX_RANK];  /* size of blocks */
+            hsize_t       hs_stride2[H5S_MAX_RANK]; /* stride */
+            hsize_t       hs_size2[H5S_MAX_RANK];   /* size this pass */
+            hsize_t       hs_nelmts1 = 0;           /* elements in request */
+            hsize_t       hs_nelmts2 = 0;           /* elements in request */
+            hsize_t       zero[8];                  /* vector of zeros */
+            hsize_t       low[H5S_MAX_RANK];        /* low bound of hyperslab */
+            hsize_t       high[H5S_MAX_RANK];       /* higher bound of hyperslab */
+
+            H5TOOLS_DEBUG("reclaim any VL memory and free unused buffers");
+            if(buf1 != NULL) {
+                /* reclaim any VL memory, if necessary */
+                if(vl_data1)
+                    H5Dvlen_reclaim(m_tid1, sid1, H5P_DEFAULT, buf1);
+                HDfree(buf1);
+                buf1 = NULL;
+            }
+            if(buf2 != NULL) {
+                /* reclaim any VL memory, if necessary */
+                if(vl_data2)
+                    H5Dvlen_reclaim(m_tid2, sid2, H5P_DEFAULT, buf2);
+                HDfree(buf2);
+                buf2 = NULL;
+            }
+
+            /* the stripmine loop */
+            HDmemset(hs_offset1, 0, sizeof hs_offset1);
+            HDmemset(hs_stride1, 0, sizeof hs_stride1);
+            HDmemset(hs_count1, 0, sizeof hs_count1);
+            HDmemset(hs_block1, 0, sizeof hs_block1);
+            HDmemset(hs_size1, 0, sizeof hs_size1);
+            HDmemset(hs_offset2, 0, sizeof hs_offset2);
+            HDmemset(hs_stride2, 0, sizeof hs_stride2);
+            HDmemset(hs_count2, 0, sizeof hs_count2);
+            HDmemset(hs_block2, 0, sizeof hs_block2);
+            HDmemset(hs_size2, 0, sizeof hs_size2);
+            HDmemset(zero, 0, sizeof zero);
+
+            /* if subsetting was requested - initialize the subsetting variables */
+            H5TOOLS_DEBUG("compare by hyperslabs: opts->nelmts=%ld - opts->m_size=%ld", opts->nelmts, opts->m_size);
+            if (opts->sset[0] != NULL) {
+                H5TOOLS_DEBUG("opts->sset[0] != NULL");
+
+                /* Check for valid settings - default if not specified */
+                if(!opts->sset[0]->start.data || !opts->sset[0]->stride.data || !opts->sset[0]->count.data || !opts->sset[0]->block.data) {
+                    /* they didn't specify a ``stride'' or ``block''. default to 1 in all
+                     * dimensions */
+                    if(!opts->sset[0]->start.data) {
+                        /* default to (0, 0, ...) for the start coord */
+                        opts->sset[0]->start.data = (hsize_t *)HDcalloc((size_t)rank1, sizeof(hsize_t));
+                        opts->sset[0]->start.len = (unsigned)rank1;
+                    }
+
+                    if(!opts->sset[0]->stride.data) {
+                        opts->sset[0]->stride.data = (hsize_t *)HDcalloc((size_t)rank1, sizeof(hsize_t));
+                        opts->sset[0]->stride.len = (unsigned)rank1;
+                        for (i = 0; i < rank1; i++)
+                            opts->sset[0]->stride.data[i] = 1;
+                    }
+
+                    if(!opts->sset[0]->count.data) {
+                        opts->sset[0]->count.data = (hsize_t *)HDcalloc((size_t)rank1, sizeof(hsize_t));
+                        opts->sset[0]->count.len = (unsigned)rank1;
+                        for (i = 0; i < rank1; i++)
+                            opts->sset[0]->count.data[i] = 1;
+                    }
+
+                    if(!opts->sset[0]->block.data) {
+                        opts->sset[0]->block.data = (hsize_t *)HDcalloc((size_t)rank1, sizeof(hsize_t));
+                        opts->sset[0]->block.len = (unsigned)rank1;
+                        for (i = 0; i < rank1; i++)
+                            opts->sset[0]->block.data[i] = 1;
+                    }
+
+                    /*-------------------------------------------------------------------------
+                     * check for block overlap
+                     *-------------------------------------------------------------------------
+                     */
+                    for(i = 0; i < rank1; i++) {
+                        if(opts->sset[0]->count.data[i] > 1) {
+                            if(opts->sset[0]->stride.data[i] < opts->sset[0]->block.data[i]) {
+                                H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "wrong subset selection[0]; blocks overlap");
+                            } /* end if */
+                        } /* end if */
+                    } /* end for */
+                }
+
+                /* Reset the total number of elements to the subset from the command */
+                opts->nelmts = 1;
+                for (i = 0; i < rank1; i++) {
+                    hs_offset1[i] = opts->sset[0]->start.data[i];
+                    hs_stride1[i] = opts->sset[0]->stride.data[i];
+                    hs_count1[i] = opts->sset[0]->count.data[i];
+                    hs_block1[i] = opts->sset[0]->block.data[i];
+                    opts->nelmts *= hs_count1[i] * hs_block1[i];
+                    hs_size1[i] = 0;
+                    H5TOOLS_DEBUG("[%d]hs_offset1:%ld, hs_stride1:%ld, hs_count1:%ld, hs_block1:%ld", i, hs_offset1[i], hs_stride1[i], hs_count1[i], hs_block1[i]);
+                }
+            }
+            if (opts->sset[1] != NULL) {
+                H5TOOLS_DEBUG("opts->sset[1] != NULL");
+
+                /* Check for valid settings - default if not specified */
+                if(!opts->sset[1]->start.data || !opts->sset[1]->stride.data || !opts->sset[1]->count.data || !opts->sset[1]->block.data) {
+                    /* they didn't specify a ``stride'' or ``block''. default to 1 in all
+                     * dimensions */
+                    if(!opts->sset[1]->start.data) {
+                        /* default to (0, 0, ...) for the start coord */
+                        opts->sset[1]->start.data = (hsize_t *)HDcalloc((size_t)rank2, sizeof(hsize_t));
+                        opts->sset[1]->start.len = (unsigned)rank2;
+                    }
+
+                    if(!opts->sset[1]->stride.data) {
+                        opts->sset[1]->stride.data = (hsize_t *)HDcalloc((size_t)rank2, sizeof(hsize_t));
+                        opts->sset[1]->stride.len = (unsigned)rank2;
+                        for (i = 0; i < rank2; i++)
+                            opts->sset[1]->stride.data[i] = 1;
+                    }
+
+                    if(!opts->sset[1]->count.data) {
+                        opts->sset[1]->count.data = (hsize_t *)HDcalloc((size_t)rank2, sizeof(hsize_t));
+                        opts->sset[1]->count.len = (unsigned)rank2;
+                        for (i = 0; i < rank2; i++)
+                            opts->sset[1]->count.data[i] = 1;
+                    }
+
+                    if(!opts->sset[1]->block.data) {
+                        opts->sset[1]->block.data = (hsize_t *)HDcalloc((size_t)rank2, sizeof(hsize_t));
+                        opts->sset[1]->block.len = (unsigned)rank2;
+                        for (i = 0; i < rank2; i++)
+                            opts->sset[1]->block.data[i] = 1;
+                    }
+
+                    /*-------------------------------------------------------------------------
+                     * check for block overlap
+                     *-------------------------------------------------------------------------
+                     */
+                    for(i = 0; i < rank2; i++) {
+                        if(opts->sset[1]->count.data[i] > 1) {
+                            if(opts->sset[1]->stride.data[i] < opts->sset[1]->block.data[i]) {
+                                H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "wrong subset selection[1]; blocks overlap");
+                            } /* end if */
+                        } /* end if */
+                    } /* end for */
+                }
+
+                for (i = 0; i < rank2; i++) {
+                    hs_offset2[i] = opts->sset[1]->start.data[i];
+                    hs_stride2[i] = opts->sset[1]->stride.data[i];
+                    hs_count2[i] = opts->sset[1]->count.data[i];
+                    hs_block2[i] = opts->sset[1]->block.data[i];
+                    hs_size2[i] = 0;
+                    H5TOOLS_DEBUG("[%d]hs_offset2:%ld, hs_stride2:%ld, hs_count2:%ld, hs_block2:%ld", i, hs_offset2[i], hs_stride2[i], hs_count2[i], hs_block2[i]);
+                }
+            }
 
             /*
              * determine the strip mine size and allocate a buffer. The strip mine is
              * a hyperslab whose size is manageable.
              */
-            sm_nbytes = p_type_nbytes;
-
-            for(i = rank1; i > 0; --i) {
-                hsize_t size = H5TOOLS_BUFSIZE / sm_nbytes;
-
-                if(size == 0) /* datum size > H5TOOLS_BUFSIZE */
-                    size = 1;
-                sm_size[i - 1] = MIN(dadims[i - 1], size);
-                sm_nbytes *= sm_size[i - 1];
-                H5TOOLS_DEBUG("sm_nbytes: %ld", sm_nbytes);
-            } /* end for */
-
-            /* malloc return code should be verified.
-             * If fail, need to handle the error.
-             * This else branch should be recoded as a separate function.
-             * Note that there are many "goto error" within this branch
-             * that fails to address freeing other objects created here.
-             * E.g., sm_space.
-             */
-            if((sm_buf1 = HDmalloc((size_t)sm_nbytes)) == NULL)
-                H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "HDmalloc failed");
-            if((sm_buf2 = HDmalloc((size_t)sm_nbytes)) == NULL)
-                H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "HDmalloc failed");
+            sm_nbytes = opts->m_size;
+            if(opts->rank > 0) {
+                for (i = opts->rank; i > 0; --i) {
+                    hsize_t size = H5TOOLS_BUFSIZE / sm_nbytes;
+                    if (size == 0) /* datum size > H5TOOLS_BUFSIZE */
+                        size = 1;
+                    H5TOOLS_DEBUG("opts->dims[%d]: %ld - size: %ld", i - 1, opts->dims[i - 1], size);
+                    if (opts->sset[1] != NULL) {
+                        sm_size[i - 1] = MIN(hs_block1[i - 1] * hs_count1[i - 1], size);
+                        sm_block[i - 1] = MIN(hs_block1[i - 1], sm_size[i - 1]);
+                    }
+                    else {
+                        sm_size[i - 1] = MIN(opts->dims[i - 1], size);
+                        sm_block[i - 1] = sm_size[i - 1];
+                    }
+                    H5TOOLS_DEBUG("sm_size[%d]: %ld - sm_block:%ld", i - 1, sm_size[i - 1], sm_block[i - 1]);
+                    sm_nbytes *= sm_size[i - 1];
+                    H5TOOLS_DEBUG("sm_nbytes: %ld", sm_nbytes);
+                }
+            }
 
-            sm_nelmts = sm_nbytes / p_type_nbytes;
-            sm_space = H5Screate_simple(1, &sm_nelmts, NULL);
+            H5TOOLS_DEBUG("opts->nelmts: %ld", opts->nelmts);
+            for(elmtno = 0; elmtno < opts->nelmts; elmtno += opts->hs_nelmts) {
+                H5TOOLS_DEBUG("elmtno: %ld - hs_nelmts1: %ld", elmtno, hs_nelmts1);
 
-            /* the stripmine loop */
-            HDmemset(hs_offset, 0, sizeof hs_offset);
-            HDmemset(zero, 0, sizeof zero);
+                if(NULL == (sm_buf1 = (unsigned char *)HDmalloc((size_t) sm_nbytes)))
+                    H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Could not allocate buffer for strip-mine");
+                if(NULL == (sm_buf2 = (unsigned char *)HDmalloc((size_t) sm_nbytes)))
+                    H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "Could not allocate buffer for strip-mine");
 
-            for(elmtno = 0; elmtno < p_nelmts; elmtno += hs_nelmts) {
                 /* calculate the hyperslab size */
-                if(rank1 > 0) {
-                    for(i = 0, hs_nelmts = 1; i < rank1; i++) {
-                        hs_size[i] = MIN(dadims[i] - hs_offset[i], sm_size[i]);
-                        hs_nelmts *= hs_size[i];
-                    } /* end for */
-                    if(H5Sselect_hyperslab(sid1, H5S_SELECT_SET, hs_offset, NULL, hs_size, NULL) < 0)
-                        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sselect_hyperslab failed");
-                    if(H5Sselect_hyperslab(sid2, H5S_SELECT_SET, hs_offset, NULL, hs_size, NULL) < 0)
+                /* initialize subset */
+                if(opts->rank > 0) {
+                    if (opts->sset[0] != NULL) {
+                        H5TOOLS_DEBUG("sset1 has data");
+                        /* calculate the potential number of elements */
+                        for(i = 0; i < rank1; i++) {
+                            H5TOOLS_DEBUG("[%d]opts->dims: %ld - hs_offset1: %ld - sm_block: %ld", i, opts->dims[i], hs_offset1[i], sm_block[i]);
+                            hs_size1[i] = MIN(opts->dims[i] - hs_offset1[i], sm_block[i]);
+                            H5TOOLS_DEBUG("hs_size1[%d]: %ld", i, hs_size1[i]);
+                        }
+                        if(H5Sselect_hyperslab(sid1, H5S_SELECT_SET, hs_offset1, hs_stride1, hs_count1, hs_size1) < 0)
+                            H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sselect_hyperslab sid1 failed");
+                    }
+                    else {
+                        for(i = 0, hs_nelmts1 = 1; i < rank1; i++) {
+                            H5TOOLS_DEBUG("[%d]opts->dims: %ld - hs_offset1: %ld - sm_block: %ld", i, opts->dims[i], hs_offset1[i], sm_block[i]);
+                            hs_size1[i] = MIN(opts->dims[i] - hs_offset1[i], sm_block[i]);
+                            H5TOOLS_DEBUG("hs_size1[%d]: %ld", i, hs_size1[i]);
+                            hs_nelmts1 *= hs_size1[i];
+                            H5TOOLS_DEBUG("hs_nelmts1:%ld *= hs_size1[%d]: %ld", hs_nelmts1, i, hs_size1[i]);
+                        }
+                        if(H5Sselect_hyperslab(sid1, H5S_SELECT_SET, hs_offset1, NULL, hs_size1, NULL) < 0)
+                            H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sselect_hyperslab sid1 failed");
+                    }
+
+                    if((ssm_nelmts = H5Sget_select_npoints(sid1)) < 0)
+                        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sget_select_npoints failed");
+                    sm_nelmts1 = (hsize_t)ssm_nelmts;
+                    H5TOOLS_DEBUG("sm_nelmts1: %ld", sm_nelmts1);
+                    hs_nelmts1 = sm_nelmts1;
+
+                    if((sm_space1 = H5Screate_simple(1, &sm_nelmts1, NULL)) < 0)
+                        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Screate_simple failed");
+
+                    if(H5Sselect_hyperslab(sm_space1, H5S_SELECT_SET, zero, NULL, &sm_nelmts1, NULL) < 0)
                         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sselect_hyperslab failed");
-                    if(H5Sselect_hyperslab(sm_space, H5S_SELECT_SET, zero, NULL, &hs_nelmts, NULL) < 0)
+
+                    if (opts->sset[1] != NULL) {
+                        H5TOOLS_DEBUG("sset2 has data");
+                        for(i = 0; i < rank2; i++) {
+                            H5TOOLS_DEBUG("[%d]opts->dims: %ld - hs_offset2: %ld - sm_block: %ld", i, opts->dims[i], hs_offset2[i], sm_block[i]);
+                            hs_size2[i] = MIN(opts->dims[i] - hs_offset2[i], sm_block[i]);
+                            H5TOOLS_DEBUG("hs_size2[%d]: %ld", i, hs_size2[i]);
+                        }
+                        if(H5Sselect_hyperslab(sid2, H5S_SELECT_SET, hs_offset2, hs_stride2, hs_count2, hs_size2) < 0)
+                            H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sselect_hyperslab sid2 failed");
+                    }
+                    else {
+                        for(i = 0, hs_nelmts2 = 1; i < rank2; i++) {
+                            H5TOOLS_DEBUG("[%d]opts->dims: %ld - hs_offset2: %ld - sm_block: %ld", i, opts->dims[i], hs_offset2[i], sm_block[i]);
+                            hs_size2[i] = MIN(opts->dims[i] - hs_offset2[i], sm_block[i]);
+                            H5TOOLS_DEBUG("hs_size2[%d]: %ld", i, hs_size2[i]);
+                            hs_nelmts2 *= hs_size2[i];
+                            H5TOOLS_DEBUG("hs_nelmts2:%ld *= hs_size2[%d]: %ld", hs_nelmts2, i, hs_size2[i]);
+                        }
+                        if(H5Sselect_hyperslab(sid2, H5S_SELECT_SET, hs_offset2, NULL, hs_size2, NULL) < 0)
+                            H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sselect_hyperslab sid2 failed");
+                    }
+
+                    if((ssm_nelmts = H5Sget_select_npoints(sid2)) < 0)
+                        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sget_select_npoints failed");
+                    sm_nelmts2 = (hsize_t)ssm_nelmts;
+                    H5TOOLS_DEBUG("sm_nelmts2: %ld", sm_nelmts2);
+                    hs_nelmts2 = sm_nelmts2;
+
+                    if((sm_space2 = H5Screate_simple(1, &sm_nelmts2, NULL)) < 0)
+                        H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Screate_simple failed");
+
+                    if(H5Sselect_hyperslab(sm_space2, H5S_SELECT_SET, zero, NULL, &sm_nelmts2, NULL) < 0)
                         H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sselect_hyperslab failed");
-                } /* end if */
+                }
                 else
-                    hs_nelmts = 1;
+                    hs_nelmts1 = 1;
+                opts->hs_nelmts = hs_nelmts1;
+                H5TOOLS_DEBUG("hs_nelmts: %ld", opts->hs_nelmts);
 
-                if(H5Dread(did1, m_tid1, sm_space, sid1, H5P_DEFAULT, sm_buf1) < 0)
+                /* read the data */
+                if(H5Dread(did1, m_tid1, sm_space1, sid1, H5P_DEFAULT, sm_buf1) < 0)
                     H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dread failed");
-                if(H5Dread(did2, m_tid2, sm_space, sid2, H5P_DEFAULT, sm_buf2) < 0)
+                if(H5Dread(did2, m_tid2, sm_space2, sid2, H5P_DEFAULT, sm_buf2) < 0)
                     H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Dread failed");
 
+                /* print array indices. get the lower bound of the hyperslab and calculate
+                   the element position at the start of hyperslab */
+                if(H5Sget_select_bounds(sid1, low, high) < 0)
+                    H5TOOLS_GOTO_ERROR(H5DIFF_ERR, "H5Sget_select_bounds failed");
+                /* initialize the current stripmine position; this is necessary to print the array indices */
+                for (j = 0; j < opts->rank; j++)
+                    opts->sm_pos[j] = low[j];
+
+                /* Assume entire data space to be printed */
+                init_acc_pos(opts->rank, opts->dims, opts->acc, opts->pos, opts->p_min_idx);
+
                 /* get array differences. in the case of hyperslab read, increment the number of differences
                 found in each hyperslab and pass the position at the beginning for printing */
-                nfound += diff_array(sm_buf1, sm_buf2, hs_nelmts, elmtno, rank1,
-                        dadims, opts, name1, name2, dam_tid, did1, did2);
-
-                /* reclaim any VL memory, if necessary */
-                if(vl_data1)
-                    H5Dvlen_reclaim(m_tid1, sm_space, H5P_DEFAULT, sm_buf1);
-                if(vl_data2)
-                    H5Dvlen_reclaim(m_tid2, sm_space, H5P_DEFAULT, sm_buf2);
+                nfound += diff_array(sm_buf1, sm_buf2, opts, did1, did2);
+
+                if(sm_buf1 != NULL) {
+                    /* reclaim any VL memory, if necessary */
+                    if(vl_data1)
+                        H5Dvlen_reclaim(m_tid1, sm_space1, H5P_DEFAULT, sm_buf1);
+                    HDfree(sm_buf1);
+                    sm_buf1 = NULL;
+                }
+                if(sm_buf2 != NULL) {
+                    /* reclaim any VL memory, if necessary */
+                    if(vl_data2)
+                        H5Dvlen_reclaim(m_tid2, sm_space2, H5P_DEFAULT, sm_buf2);
+                    HDfree(sm_buf2);
+                    sm_buf2 = NULL;
+                }
+
+                H5Sclose(sm_space1);
+                H5Sclose(sm_space2);
 
                 /* calculate the next hyperslab offset */
-                for(i = rank1, carry = 1; i > 0 && carry; --i) {
-                    hs_offset[i - 1] += hs_size[i - 1];
-                    if(hs_offset[i - 1] == dadims[i - 1])
-                        hs_offset[i - 1] = 0;
+                for(i = opts->rank, carry = 1; i > 0 && carry; --i) {
+                    if (opts->sset[0] != NULL) {
+                        H5TOOLS_DEBUG("[%d]hs_size1:%ld - hs_block1:%ld - hs_stride1:%ld", i-1, hs_size1[i-1], hs_block1[i - 1], hs_stride1[i - 1]);
+                        if(hs_size1[i - 1] >= hs_block1[i - 1]) {
+                            hs_offset1[i - 1] += hs_size1[i - 1];
+                        }
+                        else {
+                            hs_offset1[i - 1] += hs_stride1[i - 1];
+                        }
+                    }
+                    else
+                        hs_offset1[i - 1] += hs_size1[i - 1];
+                    H5TOOLS_DEBUG("[%d]hs_offset1:%ld - opts->dims:%ld", i-1, hs_offset1[i-1], opts->dims[i - 1]);
+                    if(hs_offset1[i - 1] >= opts->dims[i - 1])
+                        hs_offset1[i - 1] = 0;
                     else
                         carry = 0;
-                } /* i */
-            } /* elmtno */
-            if(sm_buf1 != NULL) {
-                HDfree(sm_buf1);
-                sm_buf1 = NULL;
-            }
-            if(sm_buf2 != NULL) {
-                HDfree(sm_buf2);
-                sm_buf2 = NULL;
-            }
-
-            H5Sclose(sm_space);
+                    H5TOOLS_DEBUG("[%d]hs_offset1:%ld", i-1, hs_offset1[i-1]);
+                    if (opts->sset[1] != NULL) {
+                        H5TOOLS_DEBUG("[%d]hs_size2:%ld - hs_block2:%ld - hs_stride2:%ld", i-1, hs_size2[i-1], hs_block2[i - 1], hs_stride2[i - 1]);
+                        if(hs_size2[i - 1] >= hs_block2[i - 1]) {
+                            hs_offset2[i - 1] += hs_size2[i - 1];
+                        }
+                        else {
+                            hs_offset2[i - 1] += hs_stride2[i - 1];
+                        }
+                    }
+                    else
+                        hs_offset2[i - 1] += hs_size2[i - 1];
+                    H5TOOLS_DEBUG("[%d]hs_offset2:%ld - opts->dims:%ld", i-1, hs_offset2[i-1], opts->dims[i - 1]);
+                    if(hs_offset2[i - 1] >= opts->dims[i - 1])
+                        hs_offset2[i - 1] = 0;
+                    H5TOOLS_DEBUG("[%d]hs_offset2:%ld", i-1, hs_offset2[i-1]);
+                }
+            } /* elmtno for loop */
         } /* hyperslab read */
-        H5TOOLS_DEBUG("can_compare complete");
+        H5TOOLS_DEBUG("can compare complete");
     } /*can_compare*/
 
 
@@ -538,12 +849,20 @@ hsize_t diff_datasetid(hid_t did1, hid_t did2, const char *obj1_name, const char
      * close
      *-------------------------------------------------------------------------
      */
-    H5TOOLS_DEBUG("reclaim any VL memory - errstat:%d", opts->err_stat);
 
 done:
     opts->err_stat = opts->err_stat | ret_value;
 
+    H5TOOLS_DEBUG("free names - errstat:%d", opts->err_stat);
     /* free */
+    if (opts->obj_name[0] != NULL)
+         HDfree(opts->obj_name[0]);
+    opts->obj_name[0] = NULL;
+    if (opts->obj_name[1] != NULL)
+         HDfree(opts->obj_name[1]);
+    opts->obj_name[1] = NULL;
+
+    H5TOOLS_DEBUG("reclaim any VL memory");
     if(buf1 != NULL) {
         /* reclaim any VL memory, if necessary */
         if(vl_data1)
@@ -558,26 +877,31 @@ done:
         HDfree(buf2);
         buf2 = NULL;
     }
+    H5TOOLS_DEBUG("reclaim any stripmine VL memory");
     if(sm_buf1 != NULL) {
         /* reclaim any VL memory, if necessary */
         if(vl_data1)
-            H5Dvlen_reclaim(m_tid1, sm_space, H5P_DEFAULT, sm_buf1);
+            H5Dvlen_reclaim(m_tid1, sm_space1, H5P_DEFAULT, sm_buf1);
         HDfree(sm_buf1);
         sm_buf1 = NULL;
     }
     if(sm_buf2 != NULL) {
         /* reclaim any VL memory, if necessary */
         if(vl_data2)
-            H5Dvlen_reclaim(m_tid2, sm_space, H5P_DEFAULT, sm_buf2);
+            H5Dvlen_reclaim(m_tid2, sm_space2, H5P_DEFAULT, sm_buf2);
         HDfree(sm_buf2);
         sm_buf2 = NULL;
     }
 
+    H5TOOLS_DEBUG("close ids");
     /* disable error reporting */
     H5E_BEGIN_TRY {
         H5Sclose(sid1);
         H5Sclose(sid2);
-        H5Sclose(sm_space);
+        H5Sclose(sm_space1);
+        H5Sclose(sm_space2);
+        H5Pclose(dcpl1);
+        H5Pclose(dcpl2);
         H5Tclose(f_tid1);
         H5Tclose(f_tid2);
         H5Tclose(m_tid1);
@@ -601,10 +925,9 @@ done:
  *-------------------------------------------------------------------------
  */
 
-int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
-                  hsize_t *dims1, hsize_t *dims2, hsize_t *maxdim1, hsize_t *maxdim2,
-                  const char *obj1_name, const char *obj2_name,
-                  diff_opt_t *opts, int is_compound)
+int
+diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2, hsize_t *dims1, hsize_t *dims2,
+                  hsize_t *maxdim1, hsize_t *maxdim2, diff_opt_t *opts, int is_compound)
 {
     H5T_class_t  tclass1;
     H5T_class_t  tclass2;
@@ -623,19 +946,21 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
     if((tclass2 = H5Tget_class(f_tid2)) < 0)
         H5TOOLS_GOTO_ERROR(FAIL, "H5Tget_class second object failed");
 
+    H5TOOLS_DEBUG("obj_names: %s - %s", opts->obj_name[0], opts->obj_name[1]);
     if(tclass1 != tclass2) {
-        if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
+        if((opts->mode_verbose || opts->mode_list_not_cmp) && opts->obj_name[0] && opts->obj_name[1]) {
             if(is_compound) {
                 parallel_print("Not comparable: <%s> has a class %s and <%s> has a class %s\n",
-                        obj1_name, get_class(tclass1),
-                        obj2_name, get_class(tclass2));
+                        opts->obj_name[0], get_class(tclass1),
+                        opts->obj_name[1], get_class(tclass2));
             }
             else {
                 parallel_print("Not comparable: <%s> is of class %s and <%s> is of class %s\n",
-                        obj1_name, get_class(tclass1),
-                        obj2_name, get_class(tclass2));
+                        opts->obj_name[0], get_class(tclass1),
+                        opts->obj_name[1], get_class(tclass2));
             }
         }
+
         opts->not_cmp = 1;
         H5TOOLS_GOTO_DONE(0);
     }
@@ -646,10 +971,11 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
      */
     switch (tclass1) {
         case H5T_TIME:
-            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
+            if((opts->mode_verbose || opts->mode_list_not_cmp) && opts->obj_name[0] && opts->obj_name[1]) {
                 parallel_print("Not comparable: <%s> and <%s> are of class %s\n",
-                        obj1_name, obj2_name, get_class(tclass2));
+                        opts->obj_name[0], opts->obj_name[1], get_class(tclass2));
             } /* end if */
+
             opts->not_cmp = 1;
             H5TOOLS_GOTO_DONE(0);
             break;
@@ -667,7 +993,7 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
         case H5T_NO_CLASS:
         case H5T_NCLASSES:
         default:
-            H5TOOLS_DEBUG("diff_can_type class - %s", get_class(tclass1));
+            H5TOOLS_DEBUG("class - %s", get_class(tclass1));
             break;
     } /* end switch */
 
@@ -675,15 +1001,15 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
      * check for equal file datatype; warning only
      *-------------------------------------------------------------------------
      */
-    if((H5Tequal(f_tid1, f_tid2) == 0) && (opts->m_verbose) && obj1_name && obj2_name) {
+    if((H5Tequal(f_tid1, f_tid2) == 0) && (opts->mode_verbose) && opts->obj_name[0] && opts->obj_name[1]) {
         H5T_class_t cl = H5Tget_class(f_tid1);
 
         parallel_print("Warning: different storage datatype\n");
         if(cl == H5T_INTEGER || cl == H5T_FLOAT) {
-            parallel_print("<%s> has file datatype ", obj1_name);
+            parallel_print("<%s> has file datatype ", opts->obj_name[0]);
             print_type(f_tid1);
             parallel_print("\n");
-            parallel_print("<%s> has file datatype ", obj2_name);
+            parallel_print("<%s> has file datatype ", opts->obj_name[1]);
             print_type(f_tid2);
             parallel_print("\n");
         }
@@ -694,18 +1020,19 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
      *-------------------------------------------------------------------------
      */
     if(rank1 != rank2) {
-        if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
-            parallel_print("Not comparable: <%s> has rank %d, dimensions ", obj1_name, rank1);
+        if((opts->mode_verbose || opts->mode_list_not_cmp) && opts->obj_name[0] && opts->obj_name[1]) {
+            parallel_print("Not comparable: <%s> has rank %d, dimensions ", opts->obj_name[0], rank1);
             print_dimensions(rank1, dims1);
             parallel_print(", max dimensions ");
             print_dimensions(rank1, maxdim1);
             parallel_print("\n" );
-            parallel_print("and <%s> has rank %d, dimensions ", obj2_name, rank2);
+            parallel_print("and <%s> has rank %d, dimensions ", opts->obj_name[1], rank2);
             print_dimensions(rank2, dims2);
             parallel_print(", max dimensions ");
             print_dimensions(rank2, maxdim2);
             parallel_print("\n");
         }
+
         opts->not_cmp = 1;
         H5TOOLS_GOTO_DONE(0);
     }
@@ -728,20 +1055,21 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
      *-------------------------------------------------------------------------
      */
     if(dim_diff == 1) {
-        if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
-            parallel_print("Not comparable: <%s> has rank %d, dimensions ", obj1_name, rank1);
+        if((opts->mode_verbose || opts->mode_list_not_cmp) && opts->obj_name[0] && opts->obj_name[1]) {
+            parallel_print("Not comparable: <%s> has rank %d, dimensions ", opts->obj_name[0], rank1);
             print_dimensions(rank1, dims1);
             if(maxdim1 && maxdim2) {
                 parallel_print(", max dimensions ");
                 print_dimensions(rank1, maxdim1);
                 parallel_print("\n" );
-                parallel_print("and <%s> has rank %d, dimensions ", obj2_name, rank2);
+                parallel_print("and <%s> has rank %d, dimensions ", opts->obj_name[1], rank2);
                 print_dimensions(rank2, dims2);
                 parallel_print(", max dimensions ");
                 print_dimensions(rank2, maxdim2);
                 parallel_print("\n");
             }
         }
+
         opts->not_cmp = 1;
         H5TOOLS_GOTO_DONE(0);
     }
@@ -750,13 +1078,13 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
      * maximum dimensions; just give a warning
      *-------------------------------------------------------------------------
      */
-    if(maxdim1 && maxdim2 && maxdim_diff == 1 && obj1_name) {
-        if(opts->m_verbose) {
+    if(maxdim1 && maxdim2 && maxdim_diff == 1 && opts->obj_name[0]) {
+        if(opts->mode_verbose) {
             parallel_print( "Warning: different maximum dimensions\n");
-            parallel_print("<%s> has max dimensions ", obj1_name);
+            parallel_print("<%s> has max dimensions ", opts->obj_name[0]);
             print_dimensions(rank1, maxdim1);
             parallel_print("\n");
-            parallel_print("<%s> has max dimensions ", obj2_name);
+            parallel_print("<%s> has max dimensions ", opts->obj_name[1]);
             print_dimensions(rank2, maxdim2);
             parallel_print("\n");
         }
@@ -765,16 +1093,17 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
     if(tclass1 == H5T_STRING) {
         htri_t vstrtype1 = -1;
         htri_t vstrtype2 = -1;
-        H5TOOLS_DEBUG("diff_can_type end - H5T_STRING");
+        H5TOOLS_DEBUG(" - H5T_STRING");
 
         vstrtype1 = H5Tis_variable_str(f_tid1);
         vstrtype2 = H5Tis_variable_str(f_tid2);
 
         /* no compare if either one but not both are variable string type */
         if (vstrtype1 != vstrtype2) {
-            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name)
+            if((opts->mode_verbose || opts->mode_list_not_cmp) && opts->obj_name[0] && opts->obj_name[1])
                 parallel_print("Not comparable: <%s> or <%s> is of mixed string type\n",
-                        obj1_name, obj2_name);
+                        opts->obj_name[0], opts->obj_name[1]);
+
             opts->not_cmp = 1;
             H5TOOLS_GOTO_DONE(0);
         }
@@ -786,17 +1115,18 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
         int   j;
         hid_t memb_type1 = H5I_INVALID_HID;
         hid_t memb_type2 = H5I_INVALID_HID;
-        H5TOOLS_DEBUG("diff_can_type end - H5T_COMPOUND");
+        H5TOOLS_DEBUG(" - H5T_COMPOUND");
 
         nmembs1 = H5Tget_nmembers(f_tid1);
         nmembs2 = H5Tget_nmembers(f_tid2);
 
         if(nmembs1 != nmembs2) {
-            if((opts->m_verbose || opts->m_list_not_cmp) && obj1_name && obj2_name) {
-                parallel_print("Not comparable: <%s> has %d members ", obj1_name, nmembs1);
-                parallel_print("<%s> has %d members ", obj2_name, nmembs2);
+            if((opts->mode_verbose || opts->mode_list_not_cmp) && opts->obj_name[0] && opts->obj_name[1]) {
+                parallel_print("Not comparable: <%s> has %d members ", opts->obj_name[0], nmembs1);
+                parallel_print("<%s> has %d members ", opts->obj_name[1], nmembs2);
                 parallel_print("\n");
             }
+
             opts->not_cmp = 1;
             H5TOOLS_GOTO_DONE(0);
         }
@@ -805,9 +1135,7 @@ int diff_can_type(hid_t f_tid1, hid_t f_tid2, int rank1, int rank2,
             memb_type1 = H5Tget_member_type(f_tid1, (unsigned)j);
             memb_type2 = H5Tget_member_type(f_tid2, (unsigned)j);
 
-            if (diff_can_type(memb_type1, memb_type2, rank1, rank2,
-                    dims1, dims2, maxdim1, maxdim2, obj1_name, obj2_name,
-                    opts, 1) != 1) {
+            if (diff_can_type(memb_type1, memb_type2, rank1, rank2, dims1, dims2, maxdim1, maxdim2, opts, 1) != 1) {
                 opts->not_cmp = 1;
                 H5Tclose(memb_type1);
                 H5Tclose(memb_type2);
@@ -826,19 +1154,17 @@ done:
 }
 
 
+#if defined (H5DIFF_DEBUG_UNUSED)
+/* this function is not currently used, but could be useful */
 /*-------------------------------------------------------------------------
  * Function: print_sizes
  *
  * Purpose: Print datatype sizes
  *-------------------------------------------------------------------------
  */
-#if defined (H5DIFF_DEBUG)
-void print_sizes( const char *obj1,
-                  const char *obj2,
-                  hid_t f_tid1,
-                  hid_t f_tid2,
-                  hid_t m_tid1,
-                  hid_t m_tid2 )
+void print_sizes( const char *obj1, const char *obj2, hid_t f_tid1, hid_t f_tid2, hid_t m_tid1, hid_t m_tid2);
+
+void print_sizes( const char *obj1, const char *obj2, hid_t f_tid1, hid_t f_tid2, hid_t m_tid1, hid_t m_tid2)
 {
     size_t  f_size1, f_size2;       /* size of type in file */
     size_t  m_size1, m_size2;       /* size of type in memory */
diff --git a/tools/lib/h5diff_util.c b/tools/lib/h5diff_util.c
index fd8eb99..59b11d6 100644
--- a/tools/lib/h5diff_util.c
+++ b/tools/lib/h5diff_util.c
@@ -211,7 +211,7 @@ diff_basename(const char *name)
  * Purpose:  Returns the type as a string
  *-------------------------------------------------------------------------
  */
-H5_ATTR_PURE H5_ATTR_CONST const char*
+H5_ATTR_CONST const char*
 get_type(h5trav_type_t type)
 {
     switch(type) {
@@ -242,7 +242,7 @@ get_type(h5trav_type_t type)
  * Purpose:  Returns the sign as a string
  *-------------------------------------------------------------------------
  */
-H5_ATTR_PURE const char*
+H5_ATTR_CONST const char*
 get_sign(H5T_sign_t sign)
 {
     switch(sign) {
@@ -270,7 +270,7 @@ get_sign(H5T_sign_t sign)
  * Purpose:  Returns the class as a string
  *-------------------------------------------------------------------------
  */
-H5_ATTR_PURE const char*
+H5_ATTR_CONST const char*
 get_class(H5T_class_t tclass)
 {
     switch(tclass) {
diff --git a/tools/lib/h5tools.c b/tools/lib/h5tools.c
index 877f081..bbd30ac 100644
--- a/tools/lib/h5tools.c
+++ b/tools/lib/h5tools.c
@@ -29,59 +29,67 @@ int       H5tools_INDENT_g = 0;
 
 
 /* global variables */
-hid_t       H5tools_ERR_STACK_g = 0;
+H5E_auto2_t lib_func;
+H5E_auto2_t tools_func;
+void       *lib_edata;
+void       *tools_edata;
+
+hid_t       H5tools_ERR_STACK_g = H5I_INVALID_HID;
 hid_t       H5tools_ERR_CLS_g = H5I_INVALID_HID;
 hid_t       H5E_tools_g = H5I_INVALID_HID;
 hid_t       H5E_tools_min_id_g = H5I_INVALID_HID;
 hid_t       H5E_tools_min_info_id_g = H5I_INVALID_HID;
 hid_t       H5E_tools_min_dbg_id_g = H5I_INVALID_HID;
-int         compound_data;
+
 FILE       *rawattrstream = NULL;      /* should initialize to stdout but gcc moans about it */
 FILE       *rawdatastream = NULL;      /* should initialize to stdout but gcc moans about it */
 FILE       *rawinstream = NULL;        /* should initialize to stdin but gcc moans about it */
 FILE       *rawoutstream = NULL;       /* should initialize to stdout but gcc moans about it */
 FILE       *rawerrorstream = NULL;     /* should initialize to stderr but gcc moans about it */
+
 int         bin_output;         /* binary output */
 int         bin_form = 0;       /* binary form, default NATIVE */
 int         region_output;      /* region output */
 int         oid_output;         /* oid output */
 int         data_output;        /* data output */
 int         attr_data_output;   /* attribute data output */
+int         compound_data;
+
 unsigned    packed_bits_num;    /* number of packed bits to display */
 unsigned    packed_data_offset; /* offset of packed bits to display */
 unsigned    packed_data_length; /* length of packed bits to display */
 unsigned long long packed_data_mask;  /* mask in which packed bits to display */
+
 int         enable_error_stack = 0;   /* re-enable error stack; disable=0 enable=1 */
 
 /* sort parameters */
-H5_index_t   sort_by           = H5_INDEX_NAME; /*sort_by [creation_order | name]  */
-H5_iter_order_t sort_order     = H5_ITER_INC; /*sort_order [ascending | descending]   */
+H5_index_t      sort_by        = H5_INDEX_NAME; /* sort_by [creation_order | name]  */
+H5_iter_order_t sort_order     = H5_ITER_INC;   /* sort_order [ascending | descending] */
 
 /* module-scoped variables */
 static int  h5tools_init_g;     /* if h5tools lib has been initialized */
 
-/* Names of VFDs */
-static const char *drivernames[]={
+/* Names of VFDs. These names are always available so that
+ * the tools can emit special messages when a VFD is asked
+ * for by name but is not compiled into the library or is
+ * somehow otherwise not enabled.
+ *
+ */
+const char *drivernames[] = {
     "sec2",
+    "direct",
+    "log",
+    "windows",
+    "stdio",
+    "core",
     "family",
     "split",
     "multi",
-#ifdef H5_HAVE_PARALLEL
     "mpio",
-#endif /* H5_HAVE_PARALLEL */
+    "ros3",
+    "hdfs",
 };
 
-/* This enum should match the entries in the above drivers_list since they
- * are indexes into the drivers_list array. */
-typedef enum {
-    SEC2_IDX = 0
-   ,FAMILY_IDX
-   ,SPLIT_IDX
-   ,MULTI_IDX
-#ifdef H5_HAVE_PARALLEL
-   ,MPIO_IDX
-#endif /* H5_HAVE_PARALLEL */
-} driver_idx;
 #define NUM_DRIVERS     (sizeof(drivernames) / sizeof(drivernames[0]))
 
 /*-------------------------------------------------------------------------
@@ -97,6 +105,10 @@ typedef enum {
 void
 h5tools_init(void)
 {
+    /* Disable error reporting */
+    H5Eget_auto2(H5E_DEFAULT, &lib_func, &lib_edata);
+    H5Eset_auto2(H5E_DEFAULT, NULL, NULL);
+
     if (!h5tools_init_g) {
         H5TOOLS_INIT_ERROR();
 
@@ -115,6 +127,29 @@ h5tools_init(void)
 
         h5tools_init_g++;
     }
+
+    /* Disable tools error reporting */
+    H5Eget_auto2(H5tools_ERR_STACK_g, &tools_func, &tools_edata);
+    H5Eset_auto2(H5tools_ERR_STACK_g, NULL, NULL);
+}
+
+/*-------------------------------------------------------------------------
+ * Function: h5tools_error_report
+ *
+ * Purpose:  Enable error stack reporting after command line is parsed.
+ *
+ * Return:   None
+ *-------------------------------------------------------------------------
+ */
+void
+h5tools_error_report(void)
+{
+    if (h5tools_init_g) {
+        if (enable_error_stack > 0) {
+            H5Eset_auto2(H5E_DEFAULT, lib_func, lib_edata);
+            H5Eset_auto2(H5tools_ERR_STACK_g, tools_func, tools_edata);
+        }
+    }
 }
 
 /*-------------------------------------------------------------------------
@@ -131,16 +166,14 @@ h5tools_init(void)
 void
 h5tools_close(void)
 {
-    H5E_auto2_t         tools_func;
-    void               *tools_edata;
     if (h5tools_init_g) {
         /* special case where only data is output to stdout */
-        if((rawoutstream == NULL) && rawdatastream && (rawdatastream == stdout))
+        if ((rawoutstream == NULL) && rawdatastream && (rawdatastream == stdout))
             HDfprintf(rawdatastream, "\n");
 
-        H5Eget_auto2(H5tools_ERR_STACK_g, &tools_func, &tools_edata);
-        if(tools_func!=NULL)
+        if (tools_func)
             H5Eprint2(H5tools_ERR_STACK_g, rawerrorstream);
+
         if (rawattrstream && rawattrstream != stdout) {
             if (fclose(rawattrstream))
                 perror("closing rawattrstream");
@@ -175,6 +208,10 @@ h5tools_close(void)
         /* Clean up the reference path table, if it's been used */
         term_ref_path_table();
 
+        /* Restore error stacks from init */
+        H5Eset_auto2(H5tools_ERR_STACK_g, tools_func, tools_edata);
+        H5Eset_auto2(H5E_DEFAULT, lib_func, lib_edata);
+
         H5TOOLS_CLOSE_ERROR();
 
         /* Shut down the library */
@@ -425,189 +462,337 @@ h5tools_set_error_file(const char *fname, int is_bin)
 }
 
 /*-------------------------------------------------------------------------
- * Function: h5tools_get_fapl
+ * Function: h5tools_set_fapl_vfd
  *
- * Purpose:  Get a FAPL for a given VFL driver name.
+ * Purpose:  Given a VFL driver name, sets the appropriate driver on the
+ *           specified FAPL.
  *
  * Return:   positive - succeeded
  *           negative - failed
  *-------------------------------------------------------------------------
  */
-static hid_t
-h5tools_get_fapl(hid_t fapl, const char *driver, unsigned *drivernum)
+static herr_t
+h5tools_set_fapl_vfd(hid_t fapl_id, h5tools_vfd_info_t *vfd_info)
 {
-    hid_t  new_fapl = H5I_INVALID_HID; /* Copy of file access property list passed in, or new property list */
     herr_t ret_value = SUCCEED;
 
-    /* Make a copy of the FAPL, for the file open call to use, eventually */
-    if (fapl == H5P_DEFAULT) {
-        if ((new_fapl = H5Pcreate(H5P_FILE_ACCESS)) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pcreate failed");
-    } /* end if */
-    else {
-        if ((new_fapl = H5Pcopy(fapl)) < 0)
-            H5TOOLS_GOTO_ERROR(FAIL, "H5Pcopy failed");
-    } /* end else */
-
-    /* Determine which driver the user wants to open the file with. Try
-     * that driver. If it can't open it, then fail. */
-    if (!HDstrcmp(driver, drivernames[SEC2_IDX])) {
-        /* SEC2 driver */
-        if (H5Pset_fapl_sec2(new_fapl) < 0)
+    /* Determine which driver the user wants to open the file with */
+    if (!HDstrcmp(vfd_info->name, drivernames[SEC2_VFD_IDX])) {
+        /* SEC2 Driver */
+        if (H5Pset_fapl_sec2(fapl_id) < 0)
             H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_sec2 failed");
+    }
+    else if (!HDstrcmp(vfd_info->name, drivernames[DIRECT_VFD_IDX])) {
+#ifdef H5_HAVE_DIRECT
+        /* Direct Driver */
+        if (H5Pset_fapl_direct(fapl_id, 1024, 4096, 8 * 4096) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_direct failed");
+#else
+        H5TOOLS_GOTO_ERROR(FAIL, "Direct VFD is not enabled");
+#endif
+    }
+    else if (!HDstrcmp(vfd_info->name, drivernames[LOG_VFD_IDX])) {
+        unsigned long long log_flags = H5FD_LOG_LOC_IO | H5FD_LOG_ALLOC;
 
-        if (drivernum)
-            *drivernum = SEC2_IDX;
+        /* Log Driver */
+        if (H5Pset_fapl_log(fapl_id, NULL, log_flags, (size_t) 0) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_log failed");
+    }
+    else if (!HDstrcmp(vfd_info->name, drivernames[WINDOWS_VFD_IDX])) {
+#ifdef H5_HAVE_WINDOWS
+        /* There is no Windows VFD - use SEC2 */
+        if (H5Pset_fapl_sec2(fapl_id) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_sec2 failed");
+#else
+        H5TOOLS_GOTO_ERROR(FAIL, "Windows VFD is not enabled");
+#endif
+    }
+    else if (!HDstrcmp(vfd_info->name, drivernames[STDIO_VFD_IDX])) {
+        /* Stdio Driver */
+        if (H5Pset_fapl_stdio(fapl_id) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_stdio failed");
+    }
+    else if (!HDstrcmp(vfd_info->name, drivernames[CORE_VFD_IDX])) {
+        /* Core Driver */
+        if (H5Pset_fapl_core(fapl_id, (size_t) H5_MB, TRUE) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_core failed");
     }
-    else if (!HDstrcmp(driver, drivernames[FAMILY_IDX])) {
+    else if (!HDstrcmp(vfd_info->name, drivernames[FAMILY_VFD_IDX])) {
         /* FAMILY Driver */
-
         /* Set member size to be 0 to indicate the current first member size
          * is the member size.
          */
-        if (H5Pset_fapl_family(new_fapl, (hsize_t) 0, H5P_DEFAULT) < 0)
+        if (H5Pset_fapl_family(fapl_id, (hsize_t) 0, H5P_DEFAULT) < 0)
             H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_family failed");
-
-        if (drivernum)
-            *drivernum = FAMILY_IDX;
     }
-    else if (!HDstrcmp(driver, drivernames[SPLIT_IDX])) {
+    else if (!HDstrcmp(vfd_info->name, drivernames[SPLIT_VFD_IDX])) {
         /* SPLIT Driver */
-        if (H5Pset_fapl_split(new_fapl, "-m.h5", H5P_DEFAULT, "-r.h5", H5P_DEFAULT) < 0)
+        if (H5Pset_fapl_split(fapl_id, "-m.h5", H5P_DEFAULT, "-r.h5", H5P_DEFAULT) < 0)
             H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_split failed");
-
-        if (drivernum)
-            *drivernum = SPLIT_IDX;
     }
-    else if (!HDstrcmp(driver, drivernames[MULTI_IDX])) {
+    else if (!HDstrcmp(vfd_info->name, drivernames[MULTI_VFD_IDX])) {
         /* MULTI Driver */
-        if (H5Pset_fapl_multi(new_fapl, NULL, NULL, NULL, NULL, TRUE) < 0)
+        if (H5Pset_fapl_multi(fapl_id, NULL, NULL, NULL, NULL, TRUE) < 0)
             H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_multi failed");
-
-        if(drivernum)
-            *drivernum = MULTI_IDX;
     }
+    else if (!HDstrcmp(vfd_info->name, drivernames[MPIO_VFD_IDX])) {
 #ifdef H5_HAVE_PARALLEL
-    else if(!HDstrcmp(driver, drivernames[MPIO_IDX])) {
         int mpi_initialized, mpi_finalized;
 
         /* MPI-I/O Driver */
+
         /* check if MPI is available. */
         MPI_Initialized(&mpi_initialized);
         MPI_Finalized(&mpi_finalized);
 
-        if(mpi_initialized && !mpi_finalized) {
-            if(H5Pset_fapl_mpio(new_fapl, MPI_COMM_WORLD, MPI_INFO_NULL) < 0)
+        if (mpi_initialized && !mpi_finalized) {
+            if (H5Pset_fapl_mpio(fapl_id, MPI_COMM_WORLD, MPI_INFO_NULL) < 0)
                 H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_mpio failed");
-            if(drivernum)
-                *drivernum = MPIO_IDX;
-        } /* end if */
-    }
+        }
+#else
+        H5TOOLS_GOTO_ERROR(FAIL, "MPI-I/O VFD is not enabled");
 #endif /* H5_HAVE_PARALLEL */
+    }
+    else if (!HDstrcmp(vfd_info->name, drivernames[ROS3_VFD_IDX])) {
+#ifdef H5_HAVE_ROS3_VFD
+        if (!vfd_info->info)
+            H5TOOLS_GOTO_ERROR(FAIL, "Read-only S3 VFD info is invalid");
+        if (H5Pset_fapl_ros3(fapl_id, (H5FD_ros3_fapl_t *)vfd_info->info) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_ros3() failed");
+#else
+        H5TOOLS_GOTO_ERROR(FAIL, "Read-only S3 VFD is not enabled");
+#endif
+    }
+    else if (!HDstrcmp(vfd_info->name, drivernames[HDFS_VFD_IDX])) {
+#ifdef H5_HAVE_LIBHDFS
+        if (!vfd_info->info)
+            H5TOOLS_GOTO_ERROR(FAIL, "HDFS VFD info is invalid");
+        if (H5Pset_fapl_hdfs(fapl_id, (H5FD_hdfs_fapl_t *)vfd_info->info) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "H5Pset_fapl_hdfs() failed");
+#else
+        H5TOOLS_GOTO_ERROR(FAIL, "The HDFS VFD is not enabled");
+#endif
+    }
     else
-        ret_value = -1;
+        H5TOOLS_GOTO_ERROR(FAIL, "invalid VFD name");
 
 done:
-    if((new_fapl != H5P_DEFAULT) && (ret_value < 0)) {
-        H5Pclose(new_fapl);
-        new_fapl = H5I_INVALID_HID;
+    return ret_value;
+}
+
+/*-------------------------------------------------------------------------
+ * Function: h5tools_get_fapl
+ *
+ * Purpose:  Copies an input fapl and then sets a VFD on it.
+ *
+ *           The returned fapl must be closed by the caller.
+ *
+ * Return:   positive - succeeded
+ *           negative - failed
+ *-------------------------------------------------------------------------
+ */
+hid_t
+h5tools_get_fapl(hid_t prev_fapl_id, h5tools_vfd_info_t *vfd_info)
+{
+    hid_t new_fapl_id = H5I_INVALID_HID;
+    hid_t ret_value = H5I_INVALID_HID;
+
+    if (prev_fapl_id < 0)
+        H5TOOLS_GOTO_ERROR(FAIL, "invalid FAPL");
+
+    /* Make a copy of the FAPL or create one if H5P_DEFAULT is specified. */
+    if (H5P_DEFAULT == prev_fapl_id) {
+        if ((new_fapl_id = H5Pcreate(H5P_FILE_ACCESS)) < 0)
+            H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "H5Pcreate failed");
+    }
+    else {
+        if ((new_fapl_id = H5Pcopy(prev_fapl_id)) < 0)
+            H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "H5Pcopy failed");
+    }
+
+    /* Set non-default virtual file driver, if requested */
+    if (vfd_info)
+        if (h5tools_set_fapl_vfd(new_fapl_id, vfd_info) < 0)
+            H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "failed to set VFD on FAPL");
+
+    ret_value = new_fapl_id;
+
+done:
+    if ((new_fapl_id >= 0) && (ret_value < 0)) {
+        H5Pclose(new_fapl_id);
+        new_fapl_id = H5I_INVALID_HID;
+    }
+
+    return ret_value;
+}
+
+/*-------------------------------------------------------------------------
+ * Function: h5tools_get_vfd_name
+ *
+ * Purpose:  Given a FAPL, retrieves the name of the VFL driver set on it
+ *           if using a native-terminal VOL connector. If a
+ *           non-native-terminal VOL connector is set on the FAPL, the
+ *           first byte of the returned driver name will be set to the null
+ *           terminator.
+ *
+ * Return:   SUCCEED/FAIL
+ *-------------------------------------------------------------------------
+ */
+herr_t
+h5tools_get_vfd_name(hid_t fapl_id, char *drivername, size_t drivername_size)
+{
+    hid_t  fapl_vol_id = H5I_INVALID_HID;
+    herr_t ret_value = SUCCEED;
+
+    if (fapl_id < 0)
+        H5TOOLS_GOTO_ERROR(FAIL, "invalid FAPL");
+    if (!drivername)
+        H5TOOLS_GOTO_ERROR(FAIL, "drivername is NULL");
+    if (drivername && !drivername_size)
+        H5TOOLS_GOTO_ERROR(FAIL, "drivername_size must be non-zero");
+
+    /* Initialize the driver name */
+    drivername[0] = '\0';
+
+    if (fapl_id == H5P_DEFAULT)
+        fapl_id = H5P_FILE_ACCESS_DEFAULT;
+
+    if (fapl_id >= 0) {
+        const char *driver_name;
+        hid_t       driver_id;
+
+        if ((driver_id = H5Pget_driver(fapl_id)) < 0)
+            H5TOOLS_GOTO_ERROR(FAIL, "failed to retrieve VFL driver ID from FAPL");
+
+        if (driver_id == H5FD_SEC2)
+            driver_name = drivernames[SEC2_VFD_IDX];
+#ifdef H5_HAVE_DIRECT
+        else if (driver_id == H5FD_DIRECT)
+            driver_name = drivernames[DIRECT_VFD_IDX];
+#endif
+        else if (driver_id == H5FD_LOG)
+            driver_name = drivernames[LOG_VFD_IDX];
+#ifdef H5_HAVE_WINDOWS
+        else if (driver_id == H5FD_WINDOWS)
+            driver_name = drivernames[WINDOWS_VFD_IDX];
+#endif
+        else if (driver_id == H5FD_STDIO)
+            driver_name = drivernames[STDIO_VFD_IDX];
+        else if (driver_id == H5FD_CORE)
+            driver_name = drivernames[CORE_VFD_IDX];
+        else if (driver_id == H5FD_FAMILY)
+            driver_name = drivernames[FAMILY_VFD_IDX];
+        else if (driver_id == H5FD_MULTI)
+            driver_name = drivernames[MULTI_VFD_IDX];
+#ifdef H5_HAVE_PARALLEL
+        else if (driver_id == H5FD_MPIO)
+            driver_name = drivernames[MPIO_VFD_IDX];
+#endif
+#ifdef H5_HAVE_ROS3_VFD
+        else if (driver_id == H5FD_ROS3)
+            driver_name = drivernames[ROS3_VFD_IDX];
+#endif
+#ifdef H5_HAVE_LIBHDFS
+        else if (driver_id == H5FD_HDFS)
+            driver_name = drivernames[HDFS_VFD_IDX];
+#endif
+        else
+            driver_name = "unknown";
+
+        HDstrncpy(drivername, driver_name, drivername_size);
+        drivername[drivername_size - 1] = '\0';
     }
 
-    return(new_fapl);
+done:
+
+    return ret_value;
 }
 
 /*-------------------------------------------------------------------------
  * Function: h5tools_fopen
  *
- * Purpose:  Loop through the various types of VFL drivers trying to open FNAME.
- *      If the HDF5 library is version 1.2 or less, then we have only the SEC2
- *      driver to try out. If the HDF5 library is greater than version 1.2,
- *      then we have the FAMILY, SPLIT, and MULTI drivers to play with.
+ * Purpose:  Opens file FNAME using the specified flags and FAPL.
  *
- *      If DRIVER is non-NULL, then it will try to open the file with that
- *      driver first. We assume that the user knows what they are doing so, if
- *      we fail, then we won't try other file drivers.
+ *           The 'use_specific_driver' parameter is used to control the
+ *           VFD connector that this routine uses to open the file
+ *           with. If 'use_specific_driver' is set to TRUE, this routine
+ *           assumes that the caller has already set a specific VFD
+ *           connector on the given FAPL and will attempt to directly use
+ *           the FAPL for opening the file. We assume that the caller knows
+ *           what they are doing; if the file is unable to be opened using
+ *           that FAPL, this routine will return H5I_INVALID_HID.
+ *
+ *           However, if 'use_specific_driver' is set to FALSE, this
+ *           routine assumes that the caller HAS NOT set a specific VFD
+ *           connector on the given FAPL and will instead loop through
+ *           the various available VFL drivers and VOL connectors trying to
+ *           open FNAME.
+ *
+ *           The list of available VFL drivers is as follows:
+ *             - If the HDF5 library is version 1.2 or less, then we have
+ *               only the SEC2 driver to try out.
+ *             - If the HDF5 library is greater than version 1.2, then we
+ *               have the FAMILY, SPLIT, and MULTI drivers to play with.
  *
  * Return:
- *      On success, returns a file id for the opened file. If DRIVERNAME is
+ *      On success, returns a file ID for the opened file. If DRIVERNAME is
  *      non-null then the first DRIVERNAME_SIZE-1 characters of the driver
  *      name are copied into the DRIVERNAME array and null terminated.
  *
- *      Otherwise, the function returns FAIL. If DRIVERNAME is non-null then
- *      the first byte is set to the null terminator.
+ *      On failure, the function returns H5I_INVALID_HID and DRIVERNAME
+ *      will not be set.
  *-------------------------------------------------------------------------
  */
 hid_t
-h5tools_fopen(const char *fname, unsigned flags, hid_t fapl, const char *driver,
+h5tools_fopen(const char *fname, unsigned flags, hid_t fapl_id, hbool_t use_specific_driver,
     char *drivername, size_t drivername_size)
 {
-    unsigned    drivernum;
-    hid_t       fid = FAIL;
-    hid_t       my_fapl = H5P_DEFAULT;
-
-    if (driver && *driver) {
-        /* Get the correct FAPL for the given driver */
-        if ((my_fapl = h5tools_get_fapl(fapl, driver, &drivernum)) < 0)
-            goto done;
-
-        /* allow error stack display if enable-error-stack has optional arg number */
-        if (enable_error_stack > 1) {
-            fid = H5Fopen(fname, flags, my_fapl);
-        }
-        else {
-            H5E_BEGIN_TRY {
-                fid = H5Fopen(fname, flags, my_fapl);
-            } H5E_END_TRY;
-        }
+    hid_t    fid = H5I_INVALID_HID;
+    hid_t    tmp_fapl_id = H5I_INVALID_HID;
+    hid_t    used_fapl_id = H5I_INVALID_HID;
+    hid_t    ret_value = H5I_INVALID_HID;
 
-        if (fid == FAIL)
-            goto done;
+    /*
+     * First try to open the file using just the given FAPL.
+     */
 
+    /* Allow error stack display if --enable-error-stack has optional arg number */
+    if (enable_error_stack > 1) {
+        fid = H5Fopen(fname, flags, fapl_id);
     }
     else {
-        /* Try to open the file using each of the drivers */
-        for (drivernum = 0; drivernum < NUM_DRIVERS; drivernum++) {
-            /* Get the correct FAPL for the given driver */
-            if((my_fapl = h5tools_get_fapl(fapl, drivernames[drivernum], NULL)) < 0)
-                goto done;
-
-            /* allow error stack display if enable-error-stack has optional arg number */
-            if (enable_error_stack > 1) {
-                fid = H5Fopen(fname, flags, my_fapl);
-            }
-            else {
-                H5E_BEGIN_TRY {
-                    fid = H5Fopen(fname, flags, my_fapl);
-                } H5E_END_TRY;
-            }
-
-            if (fid != FAIL)
-                break;
-            else {
-                /* Close the FAPL */
-                H5Pclose(my_fapl);
-                my_fapl = H5P_DEFAULT;
-            } /* end else */
-        }
+        H5E_BEGIN_TRY {
+            fid = H5Fopen(fname, flags, fapl_id);
+        } H5E_END_TRY;
     }
 
-    /* Save the driver name */
-    if (drivername && drivername_size) {
-        if (fid != FAIL) {
-            HDstrncpy(drivername, drivernames[drivernum], drivername_size);
-            drivername[drivername_size - 1] = '\0';
-        }
-        else {
-            /*no file opened*/
-            drivername[0] = '\0';
-        }
+    /* If we succeeded in opening the file, we're done. */
+    if (fid >= 0) {
+        used_fapl_id = fapl_id;
+        H5TOOLS_GOTO_DONE(fid);
     }
 
+    /*
+     * If we failed to open the file and the caller specified 'use_specific_driver'
+     * as TRUE, we should return failure now since the file couldn't be opened with
+     * the VFL driver that was set on the FAPL by the caller.
+     */
+    if (fid < 0 && use_specific_driver)
+        H5TOOLS_GOTO_ERROR(H5I_INVALID_HID, "failed to open file using specified FAPL");
+
+    /* File was unable to be opened at all */
+    ret_value = H5I_INVALID_HID;
+
 done:
-    if(my_fapl != H5P_DEFAULT)
-        H5Pclose(my_fapl);
+    /* Save the driver name */
+    if (drivername && drivername_size && ret_value >= 0)
+        if (used_fapl_id >= 0 && h5tools_get_vfd_name(used_fapl_id, drivername, drivername_size) < 0)
+            H5TOOLS_ERROR(H5I_INVALID_HID, "failed to retrieve name of VFD used to open file");
+
+    if (tmp_fapl_id >= 0)
+        H5Pclose(tmp_fapl_id);
 
-    return fid;
+    return ret_value;
 }
 
 /*-------------------------------------------------------------------------
@@ -733,8 +918,8 @@ done:
  *-------------------------------------------------------------------------
  */
 void
-h5tools_simple_prefix(FILE *stream, const h5tool_format_t *info,
-                      h5tools_context_t *ctx, hsize_t elmtno, int secnum)
+h5tools_simple_prefix(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+        hsize_t elmtno, int secnum)
 {
     h5tools_str_t prefix;
     h5tools_str_t str;          /*temporary for indentation */
@@ -762,7 +947,7 @@ h5tools_simple_prefix(FILE *stream, const h5tool_format_t *info,
     H5TOOLS_DEBUG("after CR elmtno=%ld, ctx->ndims=%d", elmtno, ctx->ndims);
 
     /* Calculate new prefix */
-    h5tools_str_prefix(&prefix, info, elmtno, ctx->ndims, ctx);
+    h5tools_str_prefix(&prefix, info, elmtno, ctx);
     H5TOOLS_DEBUG("prefix=%s - str=%s", prefix.s, str.s);
 
     /* Write new prefix to output */
@@ -829,8 +1014,8 @@ h5tools_simple_prefix(FILE *stream, const h5tool_format_t *info,
  *-------------------------------------------------------------------------
  */
 void
-h5tools_region_simple_prefix(FILE *stream, const h5tool_format_t *info,
-        h5tools_context_t *ctx, hsize_t elmtno, hsize_t *ptdata, int secnum)
+h5tools_region_simple_prefix(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+        hsize_t elmtno, hsize_t *ptdata, int secnum)
 {
     h5tools_str_t prefix;
     h5tools_str_t str;       /*temporary for indentation */
@@ -854,7 +1039,7 @@ h5tools_region_simple_prefix(FILE *stream, const h5tool_format_t *info,
     }
 
     /* Calculate new prefix */
-    h5tools_str_region_prefix(&prefix, info, elmtno, ptdata, ctx->ndims, ctx->p_max_idx, ctx);
+    h5tools_str_region_prefix(&prefix, info, elmtno, ptdata, ctx);
 
     /* Write new prefix to output */
     if (ctx->indent_level > 0)
@@ -927,9 +1112,8 @@ h5tools_region_simple_prefix(FILE *stream, const h5tool_format_t *info,
  *-------------------------------------------------------------------------
  */
 hbool_t
-h5tools_render_element(FILE *stream, const h5tool_format_t *info,
-        h5tools_context_t *ctx, h5tools_str_t *buffer, hsize_t *curr_pos,
-        size_t ncols, hsize_t local_elmt_counter, hsize_t elmt_counter)
+h5tools_render_element(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+        h5tools_str_t *buffer, hsize_t *curr_pos, size_t ncols, hsize_t local_elmt_counter, hsize_t elmt_counter)
 {
     hbool_t  dimension_break = TRUE;
     char    *s = NULL;
@@ -1098,9 +1282,8 @@ h5tools_render_element(FILE *stream, const h5tool_format_t *info,
  *-------------------------------------------------------------------------
  */
 hbool_t
-h5tools_render_region_element(FILE *stream, const h5tool_format_t *info,
-        h5tools_context_t *ctx, h5tools_str_t *buffer, hsize_t *curr_pos,
-        size_t ncols, hsize_t *ptdata, hsize_t local_elmt_counter, hsize_t elmt_counter)
+h5tools_render_region_element(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+        h5tools_str_t *buffer, hsize_t *curr_pos, size_t ncols, hsize_t *ptdata, hsize_t local_elmt_counter, hsize_t elmt_counter)
 {
     hbool_t  dimension_break = TRUE;
     char    *s = NULL;
@@ -1117,8 +1300,10 @@ h5tools_render_region_element(FILE *stream, const h5tool_format_t *info,
      * If the element would split on multiple lines if printed at our
      * current location...
      */
-    if (info->line_multi_new == 1 && (ctx->cur_column + h5tools_count_ncols(s) +
-                    HDstrlen(OPT(info->elmt_suf2, " ")) + HDstrlen(OPT(info->line_suf, ""))) > ncols) {
+    if (info->line_multi_new == 1 &&
+            (ctx->cur_column + h5tools_count_ncols(s) +
+                    HDstrlen(OPT(info->elmt_suf2, " ")) +
+                    HDstrlen(OPT(info->line_suf, ""))) > ncols) {
         if (ctx->prev_multiline) {
             /*
              * ... and the previous element also occupied more than one
@@ -1127,7 +1312,8 @@ h5tools_render_region_element(FILE *stream, const h5tool_format_t *info,
             ctx->need_prefix = TRUE;
         }
         else if ((ctx->prev_prefix_len + h5tools_count_ncols(s) +
-                HDstrlen(OPT(info->elmt_suf2, " ")) + HDstrlen(OPT(info->line_suf, ""))) <= ncols) {
+                HDstrlen(OPT(info->elmt_suf2, " ")) +
+                HDstrlen(OPT(info->line_suf, ""))) <= ncols) {
             /*
              * ...but *could* fit on one line otherwise, then we
              * should end the current line and start this element on its
@@ -1158,7 +1344,9 @@ h5tools_render_region_element(FILE *stream, const h5tool_format_t *info,
      * beginning of the line.
      */
     if (info->line_multi_new == 1 && ctx->prev_multiline &&
-            (ctx->cur_column + h5tools_count_ncols(s) + HDstrlen(OPT(info->elmt_suf2, " ")) + HDstrlen(OPT(info->line_suf, ""))) > ncols)
+            (ctx->cur_column + h5tools_count_ncols(s) +
+            HDstrlen(OPT(info->elmt_suf2, " ")) +
+            HDstrlen(OPT(info->line_suf, ""))) > ncols)
         ctx->need_prefix = TRUE;
 
     /*
@@ -1186,7 +1374,9 @@ h5tools_render_region_element(FILE *stream, const h5tool_format_t *info,
          * this check to happen for the first line
          */
         if ((!info->skip_first || local_elmt_counter) &&
-                (ctx->cur_column + HDstrlen(section) + HDstrlen(OPT(info->elmt_suf2, " ")) + HDstrlen(OPT(info->line_suf, ""))) > ncols)
+                (ctx->cur_column + HDstrlen(section) +
+                        HDstrlen(OPT(info->elmt_suf2, " ")) +
+                        HDstrlen(OPT(info->line_suf, ""))) > ncols)
             ctx->need_prefix = 1;
 
         /*
@@ -1232,27 +1422,65 @@ h5tools_render_region_element(FILE *stream, const h5tool_format_t *info,
  *-------------------------------------------------------------------------
  */
 void
-init_acc_pos(h5tools_context_t *ctx, hsize_t *dims)
+init_acc_pos(unsigned ndims, hsize_t *dims, hsize_t *acc, hsize_t *pos, hsize_t *p_min_idx)
 {
     int i;
     unsigned j;
 
     H5TOOLS_START_DEBUG("");
 
-    if(ctx->ndims > 0) {
-        ctx->acc[ctx->ndims - 1] = 1;
-        for (i = ((int)ctx->ndims - 2); i >= 0; i--) {
-            ctx->acc[i] = ctx->acc[i + 1] * dims[i + 1];
-            H5TOOLS_DEBUG("ctx->acc[%d]=%ld", i, ctx->acc[i]);
+    for (i = 0; (unsigned)i < ndims; i++)
+        p_min_idx[i] = 0;
+
+    if(ndims > 0) {
+        acc[ndims - 1] = 1;
+        for (i = ((int)ndims - 2); i >= 0; i--) {
+            acc[i] = acc[i + 1] * dims[i + 1];
+            H5TOOLS_DEBUG("acc[%d]=%ld", i, acc[i]);
         }
-        for (j = 0; j < ctx->ndims; j++)
-            ctx->pos[j] = 0;
+        for (j = 0; j < ndims; j++)
+            pos[j] = 0;
     }
 
     H5TOOLS_ENDDEBUG("");
 }
 
 /*-------------------------------------------------------------------------
+ * Function: calc_acc_pos
+ *
+ * Purpose:  Calculate the number of elements represented by a unit change
+ *           in a certain index position.
+ *
+ * Return:   void
+ *-------------------------------------------------------------------------
+ */
+hsize_t
+calc_acc_pos(unsigned ndims, hsize_t elmtno, hsize_t *acc, hsize_t *pos)
+{
+    int i;
+    hsize_t   curr_pos = elmtno;
+
+    H5TOOLS_START_DEBUG("");
+
+    if(ndims > 0) {
+        for(i = 0; i < (size_t) ndims; i++) {
+            if(curr_pos > 0) {
+                H5TOOLS_DEBUG("curr_pos=%ld - ctx->acc[%d]=%ld", curr_pos, i, acc[i]);
+                pos[i] = curr_pos / acc[i];
+                curr_pos -= acc[i] * pos[i];
+            }
+            else
+                pos[i] = 0;
+            H5TOOLS_DEBUG("curr_pos=%ld - pos[%d]=%ld - acc[%d]=%ld", curr_pos, i, pos[i], i, acc[i]);
+        }
+    }
+
+    H5TOOLS_ENDDEBUG("");
+
+    return curr_pos;
+}
+
+/*-------------------------------------------------------------------------
  * Function: render_bin_output
  *
  * Purpose:  Write one element of memory buffer to a binary file stream
@@ -1437,19 +1665,24 @@ render_bin_output(FILE *stream, hid_t container, hid_t tid, void *_mem,  hsize_t
 
                         for (block_index = 0; block_index < block_nelmts; block_index++) {
                             mem = ((unsigned char*)_mem) + block_index * size;
-                            region_id = H5Rdereference2(container, H5P_DEFAULT, H5R_DATASET_REGION, mem);
-                            if (region_id >= 0) {
-                                region_space = H5Rget_region(container, H5R_DATASET_REGION, mem);
-                                if (region_space >= 0) {
-                                    region_type = H5Sget_select_type(region_space);
-                                    if(region_type == H5S_SEL_POINTS)
-                                        render_bin_output_region_points(region_space, region_id, stream, container);
-                                    else
-                                        render_bin_output_region_blocks(region_space, region_id, stream, container);
+                            if((region_id = H5Rdereference2(container, H5P_DEFAULT, H5R_DATASET_REGION, mem)) < 0)
+                                H5TOOLS_INFO("H5Ropen_object H5T_STD_REF failed");
+                            else {
+                                if((region_space = H5Rget_region(container, H5R_DATASET_REGION, mem)) >= 0) {
+                                    if (!h5tools_is_zero(mem, H5R_DSET_REG_REF_BUF_SIZE)) {
+                                        region_type = H5Sget_select_type(region_space);
+                                        if(region_type == H5S_SEL_POINTS)
+                                            render_bin_output_region_points(region_space, region_id, stream, container);
+                                        else
+                                            render_bin_output_region_blocks(region_space, region_id, stream, container);
+                                    }
+                                    else {
+                                        H5TOOLS_INFO("H5Ropen_object H5T_STD_REF NULL");
+                                    }
                                     H5Sclose(region_space);
                                 } /* end if (region_space >= 0) */
                                 H5Dclose(region_id);
-                            } /* end if (region_id >= 0) */
+                            }
                         }
                     } /* end if (region_output... */
                 }
diff --git a/tools/lib/h5tools.h b/tools/lib/h5tools.h
index 9440e7a..fa0198e 100644
--- a/tools/lib/h5tools.h
+++ b/tools/lib/h5tools.h
@@ -539,20 +539,57 @@ typedef struct h5tools_context_t {
     int display_char;                 /* */
 } h5tools_context_t;
 
+/* VFD info structs used to set the file access property
+ * lists in the tools.
+ */
+
+typedef struct h5tools_vfd_info_t {
+
+    /* Pointer to information to be passed to the driver for its setup */
+    const void *info;
+
+    /* Name of the VFD */
+    const char *name;
+} h5tools_vfd_info_t;
+
+/* This enum should match the entries in the above 'drivernames'
+ * since they are indices into the 'drivernames' array. */
+typedef enum {
+    SEC2_VFD_IDX = 0,
+    DIRECT_VFD_IDX,
+    LOG_VFD_IDX,
+    WINDOWS_VFD_IDX,
+    STDIO_VFD_IDX,
+    CORE_VFD_IDX,
+    FAMILY_VFD_IDX,
+    SPLIT_VFD_IDX,
+    MULTI_VFD_IDX,
+    MPIO_VFD_IDX,
+    ROS3_VFD_IDX,
+    HDFS_VFD_IDX,
+} driver_idx;
+
 /* The following include, h5tools_str.h, must be after the
  * above stucts are defined. There is a dependency in the following
  * include that hasn't been identified yet. */
 
 #include "h5tools_str.h"
 
-H5TOOLS_DLLVAR h5tool_format_t h5tools_dataformat;
-H5TOOLS_DLLVAR const h5tools_dump_header_t h5tools_standardformat;
-H5TOOLS_DLLVAR const h5tools_dump_header_t* h5tools_dump_header_format;
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+H5TOOLS_DLLVAR const char *drivernames[];
+
+H5TOOLS_DLLVAR h5tool_format_t h5tools_dataformat;
+H5TOOLS_DLLVAR const h5tools_dump_header_t h5tools_standardformat;
+H5TOOLS_DLLVAR const h5tools_dump_header_t* h5tools_dump_header_format;
+H5TOOLS_DLLVAR H5E_auto2_t lib_func;
+H5TOOLS_DLLVAR H5E_auto2_t tools_func;
+H5TOOLS_DLLVAR void *lib_edata;
+H5TOOLS_DLLVAR void *tools_edata;
+
 H5TOOLS_DLLVAR unsigned packed_bits_num;    /* number of packed bits to display */
 H5TOOLS_DLLVAR unsigned packed_data_offset; /* offset of packed bits to display */
 H5TOOLS_DLLVAR unsigned packed_data_length; /* length of packed bits to display */
@@ -586,48 +623,47 @@ H5TOOLS_DLLVAR int     enable_error_stack; /* re-enable error stack; disable=0 e
 /* Definitions of useful routines */
 H5TOOLS_DLL void    h5tools_init(void);
 H5TOOLS_DLL void    h5tools_close(void);
+
+H5TOOLS_DLL void    h5tools_error_report(void);
 H5TOOLS_DLL int     h5tools_set_data_output_file(const char *fname, int is_bin);
 H5TOOLS_DLL int     h5tools_set_attr_output_file(const char *fname, int is_bin);
 H5TOOLS_DLL int     h5tools_set_input_file(const char *fname, int is_bin);
 H5TOOLS_DLL int     h5tools_set_output_file(const char *fname, int is_bin);
 H5TOOLS_DLL int     h5tools_set_error_file(const char *fname, int is_bin);
+
+H5TOOLS_DLL hid_t   h5tools_get_fapl(hid_t prev_fapl_id, h5tools_vfd_info_t *vfd_info);
+H5TOOLS_DLL herr_t  h5tools_get_vfd_name(hid_t fapl_id,
+                            char *drivername, size_t drivername_size);
 H5TOOLS_DLL hid_t   h5tools_fopen(const char *fname, unsigned flags, hid_t fapl,
-                            const char *driver, char *drivername, size_t drivername_len);
+                            hbool_t use_specific_driver, char *drivername, size_t drivername_size);
 H5TOOLS_DLL hid_t   h5tools_get_little_endian_type(hid_t type);
 H5TOOLS_DLL hid_t   h5tools_get_big_endian_type(hid_t type);
 H5TOOLS_DLL htri_t  h5tools_detect_vlen(hid_t tid);
 H5TOOLS_DLL htri_t  h5tools_detect_vlen_str(hid_t tid);
 H5TOOLS_DLL hbool_t h5tools_is_obj_same(hid_t loc_id1, const char *name1, hid_t loc_id2, const char *name2);
-H5TOOLS_DLL void    init_acc_pos(h5tools_context_t *ctx, hsize_t *dims);
+H5TOOLS_DLL void    init_acc_pos(unsigned ndims, hsize_t *dims, hsize_t *acc, hsize_t *pos, hsize_t *p_min_idx);
+H5TOOLS_DLL hsize_t calc_acc_pos(unsigned ndims, hsize_t elemtno, hsize_t *acc, hsize_t *pos);
 H5TOOLS_DLL hbool_t h5tools_is_zero(const void *_mem, size_t size);
 H5TOOLS_DLL int     h5tools_canreadf(const char* name,  hid_t dcpl_id);
 H5TOOLS_DLL int     h5tools_can_encode(H5Z_filter_t filtn);
 
-H5TOOLS_DLL void    h5tools_simple_prefix(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx, hsize_t elmtno, int secnum);
-H5TOOLS_DLL void    h5tools_region_simple_prefix(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx, hsize_t elmtno, hsize_t *ptdata, int secnum);
+H5TOOLS_DLL void    h5tools_simple_prefix(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+                            hsize_t elmtno, int secnum);
+H5TOOLS_DLL void    h5tools_region_simple_prefix(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+                            hsize_t elmtno, hsize_t *ptdata, int secnum);
 
 H5TOOLS_DLL int     render_bin_output(FILE *stream, hid_t container, hid_t tid, void *_mem, hsize_t nelmts);
-H5TOOLS_DLL int     render_bin_output_region_data_blocks(hid_t region_id, FILE *stream,
-                            hid_t container, unsigned ndims, hid_t type_id, hsize_t nblocks, hsize_t *ptdata);
-H5TOOLS_DLL hbool_t render_bin_output_region_blocks(hid_t region_space, hid_t region_id,
-                             FILE *stream, hid_t container);
-H5TOOLS_DLL int     render_bin_output_region_data_points(hid_t region_space, hid_t region_id,
-                            FILE* stream, hid_t container, unsigned ndims, hid_t type_id, hsize_t npoints);
-H5TOOLS_DLL hbool_t render_bin_output_region_points(hid_t region_space, hid_t region_id,
-                             FILE *stream, hid_t container);
-
-H5TOOLS_DLL hbool_t h5tools_render_element(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx, h5tools_str_t *buffer, hsize_t *curr_pos,
-                            size_t ncols, hsize_t local_elmt_counter, hsize_t elmt_counter);
-H5TOOLS_DLL hbool_t h5tools_render_region_element(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx, /*in,out*/
-                            h5tools_str_t *buffer,  /*string into which to render */
-                            hsize_t *curr_pos,      /*total data element position*/
-                            size_t ncols, hsize_t *ptdata,
-                            hsize_t local_elmt_counter, /*element counter*/
-                            hsize_t elmt_counter);
+H5TOOLS_DLL int     render_bin_output_region_data_blocks(hid_t region_id, FILE *stream, hid_t container,
+                            unsigned ndims, hid_t type_id, hsize_t nblocks, hsize_t *ptdata);
+H5TOOLS_DLL hbool_t render_bin_output_region_blocks(hid_t region_space, hid_t region_id, FILE *stream, hid_t container);
+H5TOOLS_DLL int     render_bin_output_region_data_points(hid_t region_space, hid_t region_id, FILE* stream, hid_t container,
+                            unsigned ndims, hid_t type_id, hsize_t npoints);
+H5TOOLS_DLL hbool_t render_bin_output_region_points(hid_t region_space, hid_t region_id, FILE *stream, hid_t container);
+
+H5TOOLS_DLL hbool_t h5tools_render_element(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx, h5tools_str_t *buffer,
+                            hsize_t *curr_pos, size_t ncols, hsize_t local_elmt_counter, hsize_t elmt_counter);
+H5TOOLS_DLL hbool_t h5tools_render_region_element(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx, h5tools_str_t *buffer,
+                            hsize_t *curr_pos, size_t ncols, hsize_t *ptdata, hsize_t local_elmt_counter, hsize_t elmt_counter);
 
 #ifdef __cplusplus
 }
diff --git a/tools/lib/h5tools_dump.c b/tools/lib/h5tools_dump.c
index b10e0a7..01c4655 100644
--- a/tools/lib/h5tools_dump.c
+++ b/tools/lib/h5tools_dump.c
@@ -253,9 +253,8 @@ h5tools_dump_init(void)
  *-------------------------------------------------------------------------
  */
 int
-h5tools_dump_simple_data(FILE *stream, const h5tool_format_t *info, hid_t container,
-                         h5tools_context_t *ctx,    /* in,out */
-                         unsigned flags, hsize_t nelmts, hid_t type, void *_mem)
+h5tools_dump_simple_data(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,    /* in,out */
+                         hid_t container, unsigned flags, hsize_t nelmts, hid_t type, void *_mem)
 {
     unsigned char *mem = (unsigned char*) _mem;
     hsize_t        i;               /* element counter  */
@@ -323,6 +322,146 @@ h5tools_dump_simple_data(FILE *stream, const h5tool_format_t *info, hid_t contai
     return ret_value;
 }
 
+/*-------------------------------------------------------------------------
+ * Audience:    Public
+ * Chapter:     H5Tools Library
+ * Purpose: Print some values from an attribute referenced by object reference.
+ *
+ * Description:
+ *      This is a special case subfunction to dump aa attribute references.
+ *
+ * Return:
+ *      The function returns False if the last dimension has been reached, otherwise True
+ *
+ * In/Out:
+ *      h5tools_context_t *ctx
+ *      hsize_t *curr_pos
+ *
+ * Parameters Description:
+ *      h5tools_str_t *buffer is the string into which to render
+ *      hsize_t curr_pos is the total data element position
+ *      size_t ncols
+ *      hsize_t region_elmt_counter is the region element loop counter
+ *      hsize_t elmt_count is the data element loop counter
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+h5tools_dump_region_attribute(hid_t region_id,
+        FILE *stream, const h5tool_format_t *info,
+        h5tools_context_t *ctx,       /* in,out */
+        h5tools_str_t *buffer,        /* string into which to render */
+        hsize_t *curr_pos,            /* total data element position */
+        size_t ncols, hsize_t region_elmt_counter,    /* element counter */
+        hsize_t elmt_counter)
+{
+    hbool_t         dimension_break = TRUE;
+    hid_t           atype = H5I_INVALID_HID;
+    hid_t           type_id = H5I_INVALID_HID;
+    hid_t           region_space = H5I_INVALID_HID;
+    h5tool_format_t outputformat; /* Use to disable prefix for DATA attribute display */
+    hbool_t         past_catch = FALSE;
+    hbool_t         ret_value = TRUE;
+
+    HDassert(info);
+    HDassert(ctx);
+    HDassert(buffer);
+
+    outputformat = *info;
+    outputformat.idx_fmt   = "";
+    outputformat.idx_n_fmt = "";
+    outputformat.idx_sep   = "";
+    outputformat.line_pre  = "";
+
+    H5TOOLS_DEBUG("enter file=%p", (void*)stream);
+    H5TOOLS_DEBUG("rawdata file=%p", (void*)rawdatastream);
+
+    /* Render the region { element begin */
+    h5tools_str_reset(buffer);
+
+    h5tools_str_append(buffer, " {");
+    dimension_break = h5tools_render_element(stream, &outputformat, ctx, buffer, curr_pos, ncols, region_elmt_counter, elmt_counter);
+    /* Render the region { element end */
+
+    if((region_space = H5Aget_space(region_id)) < 0)
+        H5TOOLS_GOTO_ERROR(dimension_break, "H5Aget_space failed");
+    if((atype = H5Aget_type(region_id)) < 0)
+        H5TOOLS_GOTO_ERROR(dimension_break, "H5Aget_type failed");
+    if((type_id = H5Tget_native_type(atype, H5T_DIR_DEFAULT)) < 0)
+        H5TOOLS_GOTO_ERROR(dimension_break, "H5Tget_native_type failed");
+
+    ctx->indent_level++;
+    ctx->need_prefix = TRUE;
+
+    /* Render the datatype element begin */
+    h5tools_str_reset(buffer);
+    h5tools_str_append(buffer, "%s %s ",
+                        h5tools_dump_header_format->datatypebegin,
+                        h5tools_dump_header_format->datatypeblockbegin);
+
+    ctx->need_prefix = TRUE;
+    ctx->indent_level++;
+    h5tools_print_datatype(stream, buffer, info, ctx, atype, TRUE);
+    ctx->indent_level--;
+
+    if (HDstrlen(h5tools_dump_header_format->datatypeblockend)) {
+        h5tools_str_append(buffer, "%s", h5tools_dump_header_format->datatypeblockend);
+        if (HDstrlen(h5tools_dump_header_format->datatypeend))
+            h5tools_str_append(buffer, " ");
+    }
+    if (HDstrlen(h5tools_dump_header_format->datatypeend))
+        h5tools_str_append(buffer, "%s", h5tools_dump_header_format->datatypeend);
+
+    dimension_break = h5tools_render_element(stream, info, ctx, buffer, curr_pos, ncols, region_elmt_counter, elmt_counter);
+    /* Render the datatype element end */
+
+    ctx->need_prefix = TRUE;
+
+    /* Render the dataspace element begin */
+    h5tools_str_reset(buffer);
+    h5tools_str_append(buffer, "%s ", h5tools_dump_header_format->dataspacebegin);
+
+    h5tools_print_dataspace(buffer, region_space);
+
+    if (HDstrlen(h5tools_dump_header_format->dataspaceblockend)) {
+        h5tools_str_append(buffer, "%s", h5tools_dump_header_format->dataspaceblockend);
+        if (HDstrlen(h5tools_dump_header_format->dataspaceend))
+            h5tools_str_append(buffer, " ");
+    }
+    if (HDstrlen(h5tools_dump_header_format->dataspaceend))
+        h5tools_str_append(buffer, "%s", h5tools_dump_header_format->dataspaceblockend);
+
+    dimension_break = h5tools_render_element(stream, info, ctx, buffer, curr_pos, ncols, region_elmt_counter, elmt_counter);
+    /* Render the dataspace element end */
+
+    if (region_output) {
+        ctx->need_prefix = TRUE;
+
+        h5tools_dump_data(stream, &outputformat, ctx, region_id, FALSE);
+    }
+
+done:
+    if(H5Tclose(type_id) < 0)
+        H5TOOLS_ERROR(dimension_break, "H5Tclose failed");
+
+    if(H5Tclose(atype) < 0)
+        H5TOOLS_ERROR(dimension_break, "H5Tclose failed");
+
+    ctx->indent_level--;
+    ctx->need_prefix = TRUE;
+
+    /* Render the region } element begin */
+    h5tools_str_reset(buffer);
+    h5tools_str_append(buffer, "}");
+    dimension_break = h5tools_render_element(stream, info, ctx, buffer, curr_pos, ncols, region_elmt_counter, elmt_counter);
+    /* Render the region } element end */
+
+    H5_LEAVE(dimension_break)
+
+CATCH
+
+    H5TOOLS_ENDDEBUG("");
+    return ret_value;
+}
 
 /*-------------------------------------------------------------------------
  * Audience:    Public
@@ -428,9 +567,11 @@ h5tools_print_region_data_blocks(hid_t region_id, FILE *stream, const h5tool_for
                 ctx.indent_level++;
                 if(H5Sget_simple_extent_dims(mem_space, total_size, NULL) >= 0) {
                     /* assume entire data space to be printed */
+                    init_acc_pos(ctx.ndims, total_size, ctx.acc, ctx.pos, ctx.p_min_idx);
+
+                    /* reset data space to be printed */
                     for (indx = 0; indx < (unsigned)ctx.ndims; indx++)
                         ctx.p_min_idx[indx] = start[indx];
-                    init_acc_pos(&ctx, total_size);
 
                     /* print the data */
                     region_flags = START_OF_DATA;
@@ -799,9 +940,7 @@ h5tools_print_region_data_points(hid_t region_space, hid_t region_id,
 
         if(H5Sget_simple_extent_dims(mem_space, total_size, NULL) >= 0) {
             /* assume entire data space to be printed */
-            for (indx = 0; indx < ctx.ndims; indx++)
-                ctx.p_min_idx[indx] = 0;
-            init_acc_pos(&ctx, total_size);
+            init_acc_pos(ctx.ndims, total_size, ctx.acc, ctx.pos, ctx.p_min_idx);
 
             /* print the data */
             region_flags = START_OF_DATA;
@@ -1113,7 +1252,6 @@ h5tools_print_simple_subset(FILE *stream, const h5tool_format_t *info, h5tools_c
     size_t            j;                       /* counters  */
     hsize_t           zero[1] = {0};           /* vector of zeros */
     unsigned int      flags;                   /* buffer extent flags */
-    hsize_t           elmtno;                  /* elemnt index  */
     hsize_t           low[H5S_MAX_RANK];       /* low bound of hyperslab */
     hsize_t           high[H5S_MAX_RANK];      /* higher bound of hyperslab */
     size_t            p_type_nbytes;           /* size of memory type */
@@ -1134,9 +1272,6 @@ h5tools_print_simple_subset(FILE *stream, const h5tool_format_t *info, h5tools_c
     if ((size_t) ctx->ndims > NELMTS(sm_size))
         H5TOOLS_THROW(FAIL, "ndims and sm_size comparision failed");
 
-    if (ctx->ndims > 0)
-        init_acc_pos(ctx, total_size);
-
     size_row_block = ctx->sset->block.data[row_dim];
 
     /* Check if we have VL data in the dataset's datatype */
@@ -1207,27 +1342,25 @@ h5tools_print_simple_subset(FILE *stream, const h5tool_format_t *info, h5tools_c
             for (i = 0; i < ctx->ndims; i++)
                 ctx->p_max_idx[i] = ctx->p_min_idx[i] + MIN(total_size[i], sm_size[i]);
 
-            /* print array indices. get the lower bound of the hyperslab and calulate
-             the element position at the start of hyperslab */
+            /* print array indices. get the lower bound of the hyperslab and calculate
+               the element position at the start of hyperslab */
             if(H5Sget_select_bounds(f_space, low, high) < 0)
                 H5TOOLS_THROW(FAIL, "H5Sget_select_bounds failed");
 
-            elmtno = 0;
+            /* initialize the current stripmine position; this is necessary to print the array indices */
+            ctx->sm_pos = 0;
             for (i = 0; i < (size_t) ctx->ndims - 1; i++) {
                 hsize_t offset = 1; /* accumulation of the previous dimensions */
                 for (j = i + 1; j < (size_t) ctx->ndims; j++)
                     offset *= total_size[j];
-                elmtno += low[i] * offset;
+                ctx->sm_pos += low[i] * offset;
             }
-            elmtno += low[ctx->ndims - 1];
+            ctx->sm_pos += low[ctx->ndims - 1];
 
-            /* initialize the current stripmine position; this is necessary to print the array
-             indices */
-            ctx->sm_pos = elmtno;
 
             ctx->need_prefix = TRUE;
 
-            if(h5tools_dump_simple_data(stream, info, dset, ctx, flags, sm_nelmts, p_type, sm_buf) < 0)
+            if(h5tools_dump_simple_data(stream, info, ctx, dset, flags, sm_nelmts, p_type, sm_buf) < 0)
                 H5TOOLS_THROW(FAIL, "h5tools_dump_simple_data failed");
 
             /* Reclaim any VL memory, if necessary */
@@ -1432,7 +1565,6 @@ h5tools_dump_simple_subset(FILE *stream, const h5tool_format_t *info, h5tools_co
 {
     int     sndims;
     hid_t   f_space = H5I_INVALID_HID;            /* file data space */
-    size_t  i;                       /* counters  */
     hsize_t total_size[H5S_MAX_RANK];/* total size of dataset*/
     hbool_t past_catch = FALSE;
     herr_t  ret_value = SUCCEED;
@@ -1446,12 +1578,10 @@ h5tools_dump_simple_subset(FILE *stream, const h5tool_format_t *info, h5tools_co
     ctx->ndims = (unsigned)sndims;
 
     /* assume entire data space to be printed */
-    if (ctx->ndims > 0)
-        for (i = 0; i < (size_t) ctx->ndims; i++)
-            ctx->p_min_idx[i] = 0;
-
     if(H5Sget_simple_extent_dims(f_space, total_size, NULL) < 0)
         H5TOOLS_THROW(FAIL, "H5Sget_simple_extent_dims failed");
+    init_acc_pos(ctx->ndims, total_size, ctx->acc, ctx->pos, ctx->p_min_idx);
+
     ctx->size_last_dim = total_size[ctx->ndims - 1];
 
     /* Set the compound datatype field list for display */
@@ -1483,38 +1613,37 @@ CATCH
  *-------------------------------------------------------------------------
  */
 static int
-h5tools_dump_simple_dset(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
-                         hid_t dset, hid_t p_type)
+h5tools_dump_simple_dset(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx, hid_t dset, hid_t p_type)
 {
-    hid_t               f_space = H5I_INVALID_HID;                  /* file data space */
-    hsize_t             elmtno;                   /* counter  */
-    size_t              i;                        /* counter  */
-    int                 sndims;                   /* rank of dataspace */
-    int                 carry;                    /* counter carry value */
-    hsize_t             zero[8];                  /* vector of zeros */
-    unsigned int        flags;                    /* buffer extent flags */
-    hsize_t             total_size[H5S_MAX_RANK]; /* total size of dataset*/
-    hbool_t             past_catch = FALSE;
+    hid_t            f_space = H5I_INVALID_HID; /* file data space */
+    hsize_t          elmtno;                    /* counter  */
+    size_t           i = 0;                     /* counter  */
+    int              sndims;                    /* rank of dataspace */
+    int              carry;                     /* counter carry value */
+    hsize_t          zero[8];                   /* vector of zeros */
+    unsigned int     flags;                     /* buffer extent flags */
+    hsize_t          total_size[H5S_MAX_RANK];  /* total size of dataset*/
+    hbool_t          past_catch = FALSE;
 
     /* Print info */
-    size_t              p_type_nbytes;            /* size of memory type */
-    hsize_t             p_nelmts;                 /* total selected elmts */
+    size_t           p_type_nbytes;             /* size of memory type */
+    hsize_t          p_nelmts;                  /* total selected elmts */
 
     /* Stripmine info */
-    hsize_t             sm_size[H5S_MAX_RANK];    /* stripmine size */
-    hsize_t             sm_nbytes;                /* bytes per stripmine */
-    hsize_t             sm_nelmts;                /* elements per stripmine*/
-    unsigned char      *sm_buf = NULL;            /* buffer for raw data */
-    hid_t               sm_space = H5I_INVALID_HID;                 /* stripmine data space */
+    hsize_t          sm_size[H5S_MAX_RANK];     /* stripmine size */
+    hsize_t          sm_nbytes;                 /* bytes per stripmine */
+    hsize_t          sm_nelmts;                 /* elements per stripmine*/
+    unsigned char   *sm_buf = NULL;             /* buffer for raw data */
+    hid_t            sm_space = H5I_INVALID_HID; /* stripmine data space */
 
     /* Hyperslab info */
-    hsize_t             hs_offset[H5S_MAX_RANK];  /* starting offset */
-    hsize_t             hs_size[H5S_MAX_RANK];    /* size this pass */
-    hsize_t             hs_nelmts;                /* elements in request */
+    hsize_t          hs_offset[H5S_MAX_RANK];   /* starting offset */
+    hsize_t          hs_size[H5S_MAX_RANK];     /* size this pass */
+    hsize_t          hs_nelmts;                 /* elements in request */
 
     /* VL data special information */
-    unsigned int        vl_data = 0; /* contains VL datatypes */
-    int                 ret_value = 0;
+    unsigned int     vl_data = 0;               /* contains VL datatypes */
+    int              ret_value = 0;
 
     H5TOOLS_START_DEBUG("");
     if (H5I_INVALID_HID == (f_space = H5Dget_space(dset)))
@@ -1530,11 +1659,8 @@ h5tools_dump_simple_dset(FILE *stream, const h5tool_format_t *info, h5tools_cont
         H5TOOLS_GOTO_ERROR((-1), "ctx->ndims > NELMTS(sm_size) failed");
 
     /* Assume entire data space to be printed */
-    if (ctx->ndims > 0)
-        for (i = 0; i < (size_t)ctx->ndims; i++)
-            ctx->p_min_idx[i] = 0;
-
     H5Sget_simple_extent_dims(f_space, total_size, NULL);
+    init_acc_pos(ctx->ndims, total_size, ctx->acc, ctx->pos, ctx->p_min_idx);
 
     /* calculate the number of elements we're going to print */
     p_nelmts = 1;
@@ -1580,8 +1706,6 @@ h5tools_dump_simple_dset(FILE *stream, const h5tool_format_t *info, h5tools_cont
         sm_space = H5Screate_simple(1, &sm_nelmts, NULL);
         H5TOOLS_DEBUG("sm_nelmts size:%ld", sm_nelmts);
 
-        if (ctx->ndims > 0)
-            init_acc_pos(ctx, total_size);
         H5TOOLS_DEBUG("ctx->ndims:%d", ctx->ndims);
 
         /* The stripmine loop */
@@ -1622,7 +1746,7 @@ h5tools_dump_simple_dset(FILE *stream, const h5tool_format_t *info, h5tools_cont
                 indices */
                 ctx->sm_pos = elmtno;
 
-                if(h5tools_dump_simple_data(stream, info, dset, ctx, flags, hs_nelmts, p_type, sm_buf) < 0)
+                if(h5tools_dump_simple_data(stream, info, ctx, dset, flags, hs_nelmts, p_type, sm_buf) < 0)
                     H5TOOLS_ERROR((-1), "h5tools_dump_simple_data failed");
 
                 /* Reclaim any VL memory, if necessary */
@@ -1701,11 +1825,8 @@ h5tools_dump_simple_mem(FILE *stream, const h5tool_format_t *info, h5tools_conte
         H5TOOLS_THROW((-1), "ctx->ndims > NELMTS(ctx->p_min_idx) failed");
 
     /* Assume entire data space to be printed */
-    if (ctx->ndims > 0)
-        for (i = 0; i < (size_t)ctx->ndims; i++)
-            ctx->p_min_idx[i] = 0;
-
     H5Sget_simple_extent_dims(f_space, total_size, NULL);
+    init_acc_pos(ctx->ndims, total_size, ctx->acc, ctx->pos, ctx->p_min_idx);
 
     /* calculate the number of elements we're going to print */
     p_nelmts = 1;
@@ -1728,14 +1849,12 @@ h5tools_dump_simple_mem(FILE *stream, const h5tool_format_t *info, h5tools_conte
     alloc_size = p_nelmts * H5Tget_size(p_type);
     HDassert(alloc_size == (hsize_t)((size_t)alloc_size)); /*check for overflow*/
     if (NULL != (buf = (unsigned char *)HDmalloc((size_t)alloc_size))) {
-        if (ctx->ndims > 0)
-            init_acc_pos(ctx, total_size);
         H5TOOLS_DEBUG("ctx->ndims:%d", ctx->ndims);
 
         H5TOOLS_DEBUG("Read the data");
         /* Read the data */
         if (H5Aread(attr_id, p_type, buf) >= 0) {
-            if(h5tools_dump_simple_data(stream, info, attr_id, ctx, START_OF_DATA | END_OF_DATA, p_nelmts, p_type, buf) < 0)
+            if(h5tools_dump_simple_data(stream, info, ctx, attr_id, START_OF_DATA | END_OF_DATA, p_nelmts, p_type, buf) < 0)
                 H5TOOLS_ERROR((-1), "h5tools_dump_simple_data failed");
 
             /* Reclaim any VL memory, if necessary */
@@ -2394,9 +2513,12 @@ h5tools_print_datatype(FILE *stream, h5tools_str_t *buffer, const h5tool_format_
         if (H5Tequal(type, H5T_STD_REF_DSETREG) == TRUE) {
             h5tools_str_append(buffer, " { H5T_STD_REF_DSETREG }");
         }
-        else {
+        else if (H5Tequal(type, H5T_STD_REF_OBJ) == TRUE) {
             h5tools_str_append(buffer, " { H5T_STD_REF_OBJECT }");
         }
+        else {
+            h5tools_str_append(buffer, " { UNDEFINED }");
+        }
         break;
 
     case H5T_ENUM:
@@ -2959,7 +3081,7 @@ h5tools_print_fill_value(h5tools_str_t *buffer/*in,out*/, const h5tool_format_t
  */
 void
 h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
-        h5tools_context_t *ctx, hid_t dcpl_id, hid_t type_id, hid_t obj_id)
+        h5tools_context_t *ctx, hid_t dcpl_id, hid_t type_id, hid_t dset_id)
 {
     int              nfilters;       /* number of filters */
     int              rank;           /* rank */
@@ -2990,7 +3112,7 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
     if (info->line_ncols > 0)
         ncols = info->line_ncols;
 
-    storage_size = H5Dget_storage_size(obj_id);
+    storage_size = H5Dget_storage_size(dset_id);
     nfilters = H5Pget_nfilters(dcpl_id);
     HDstrcpy(f_name,"\0");
 
@@ -3031,8 +3153,8 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
                 double ratio = 0;
                 int ok = 0;
 
-                hid_t tid = H5Dget_type(obj_id);
-                hid_t sid = H5Dget_space(obj_id);
+                hid_t tid = H5Dget_type(dset_id);
+                hid_t sid = H5Dget_space(dset_id);
                 size_t datum_size = H5Tget_size(tid);
                 int ndims = H5Sget_simple_extent_dims(sid, dims, NULL);
 
@@ -3090,16 +3212,15 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
             break;
         case H5D_CONTIGUOUS:
             {
-                int next;
+                int n_external;
 
-                next = H5Pget_external_count(dcpl_id);
+                n_external = H5Pget_external_count(dcpl_id);
 
-                /*-------------------------------------------------------------------------
-                 * EXTERNAL_FILE
-                 *-------------------------------------------------------------------------
-                 */
                 ctx->indent_level++;
-                if (next) {
+                if (n_external) {
+
+                    /* EXTERNAL FILE */
+
                     ctx->need_prefix = TRUE;
 
                     h5tools_str_reset(&buffer);
@@ -3113,7 +3234,7 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
                     h5tools_render_element(stream, info, ctx, &buffer, &curr_pos, (size_t) ncols, (hsize_t) 0, (hsize_t) 0);
 
                     ctx->indent_level++;
-                    for (j = 0; j < (unsigned) next; j++) {
+                    for (j = 0; j < (unsigned) n_external; j++) {
                         H5Pget_external(dcpl_id, j, sizeof(name), name, &offset, &size);
 
                         ctx->need_prefix = TRUE;
@@ -3134,6 +3255,8 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
                 else {
                     haddr_t ioffset;
 
+                    /* NORMAL FILE */
+
                     ctx->need_prefix = TRUE;
 
                     h5tools_str_reset(&buffer);
@@ -3149,7 +3272,7 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
                     ctx->need_prefix = TRUE;
 
                     h5tools_str_reset(&buffer);
-                    ioffset = H5Dget_offset(obj_id);
+                    ioffset = H5Dget_offset(dset_id);
                     h5tools_str_append(&buffer, "OFFSET "H5_PRINTF_HADDR_FMT, ioffset);
                     h5tools_render_element(stream, info, ctx, &buffer, &curr_pos, (size_t) ncols, (hsize_t) 0, (hsize_t) 0);
                 }
@@ -3160,23 +3283,23 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
         case H5D_VIRTUAL:
             {
                 char dsetname[256];     /* virtual datset name       */
-                size_t vmaps;
+                size_t n_vmaps;
 
-                H5Pget_virtual_count(dcpl_id, &vmaps);
+                H5Pget_virtual_count(dcpl_id, &n_vmaps);
 
-                if (vmaps) {
-                    size_t next;
-                    ssize_t ssize_out;
+                if (n_vmaps) {
+                    size_t curr_vmap;
+                    ssize_t H5_ATTR_NDEBUG_UNUSED ssize_out;
 
                     ctx->indent_level++;
-                    for (next = 0; next < (unsigned) vmaps; next++) {
-                        hid_t virtual_vspace = H5Pget_virtual_vspace(dcpl_id, next);
-                        hid_t virtual_srcspace = H5Pget_virtual_srcspace(dcpl_id, next);
+                    for (curr_vmap = 0; curr_vmap < n_vmaps; curr_vmap++) {
+                        hid_t virtual_vspace = H5Pget_virtual_vspace(dcpl_id, curr_vmap);
+                        hid_t virtual_srcspace = H5Pget_virtual_srcspace(dcpl_id, curr_vmap);
 
                         ctx->need_prefix = TRUE;
 
                         h5tools_str_reset(&buffer);
-                        h5tools_str_append(&buffer, "%s %ld %s ", VDS_MAPPING, next, BEGIN);
+                        h5tools_str_append(&buffer, "%s %ld %s ", VDS_MAPPING, curr_vmap, BEGIN);
                         h5tools_render_element(stream, info, ctx, &buffer, &curr_pos, (size_t) ncols, (hsize_t) 0, (hsize_t) 0);
 
                         ctx->indent_level++;
@@ -3207,14 +3330,14 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
 
                         ctx->indent_level++;
 
-                        ssize_out = H5Pget_virtual_filename(dcpl_id, next, NULL, 0);
-                        if((size_t)ssize_out >= sizeof(name))
-                            error_msg("H5Pget_virtual_filename call returned size larger then buffer", ssize_out);
-                        H5Pget_virtual_filename(dcpl_id, next, name, sizeof(name));
-                        ssize_out = H5Pget_virtual_dsetname(dcpl_id, next, NULL, 0);
-                        if((size_t)ssize_out >= sizeof(name))
-                            error_msg("H5Pget_virtual_dsetname call returned size larger then buffer", ssize_out);
-                        H5Pget_virtual_dsetname(dcpl_id, next, dsetname, sizeof(dsetname));
+                        ssize_out = H5Pget_virtual_filename(dcpl_id, curr_vmap, NULL, 0);
+                        HDassert(ssize_out > 0);
+                        HDassert((size_t)ssize_out < sizeof(name));
+                        H5Pget_virtual_filename(dcpl_id, curr_vmap, name, sizeof(name));
+                        ssize_out = H5Pget_virtual_dsetname(dcpl_id, curr_vmap, NULL, 0);
+                        HDassert(ssize_out > 0);
+                        HDassert((size_t)ssize_out < sizeof(name));
+                        H5Pget_virtual_dsetname(dcpl_id, curr_vmap, dsetname, sizeof(dsetname));
 
                         ctx->need_prefix = TRUE;
 
@@ -3478,7 +3601,7 @@ h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
             break;
         case H5D_FILL_VALUE_USER_DEFINED:
             ctx->indent_level--;
-            h5tools_print_fill_value(&buffer, info, ctx, dcpl_id, type_id, obj_id);
+            h5tools_print_fill_value(&buffer, info, ctx, dcpl_id, type_id, dset_id);
             ctx->indent_level++;
             break;
         case H5D_FILL_VALUE_ERROR:
@@ -3572,8 +3695,7 @@ h5tools_dump_comment(FILE *stream, const h5tool_format_t *info, h5tools_context_
 
     cmt_bufsize = H5Oget_comment(obj_id, comment, buf_size);
 
-    /* call H5Oget_comment again with the correct value.
-     * If the call to H5Oget_comment returned an error, skip this block */
+    /* call H5Oget_comment again with the correct value */
     if (cmt_bufsize > 0) {
         comment = (char *)HDmalloc((size_t)(cmt_bufsize+1)); /* new_size including null terminator */
         if(comment) {
@@ -3588,7 +3710,7 @@ h5tools_dump_comment(FILE *stream, const h5tool_format_t *info, h5tools_context_
                 h5tools_render_element(stream, info, ctx, &buffer, &curr_pos, (size_t)ncols, (hsize_t)0, (hsize_t)0);
 
                 h5tools_str_close(&buffer);
-            } /* end if */
+            }
             HDfree(comment);
         }
     }
@@ -3817,6 +3939,100 @@ h5tools_dump_subsetting_header(FILE *stream, const h5tool_format_t *info, h5tool
 }
 
 /*-------------------------------------------------------------------------
+ * Function:    dump_reference
+ *
+ * Purpose:     Dump reference data
+ *
+ * Return:      void
+ *-------------------------------------------------------------------------
+ */
+void
+h5tools_dump_reference(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx, hid_t container, hid_t f_type, unsigned char *region_buf, int ndims)
+{
+    hid_t               region_id = H5I_INVALID_HID;
+    hid_t               region_sid = H5I_INVALID_HID;
+    hsize_t             elmt_counter = 0;  /*counts the # elements printed. */
+    size_t              ncols = 80;        /* available output width        */
+    int                 i;
+    size_t              nsize;
+    hsize_t             curr_pos = 0;      /* total data element position   */
+    h5tools_str_t       buffer;            /* string into which to render   */
+    h5tools_context_t   datactx;           /* print context  */
+
+    H5TOOLS_START_DEBUG("");
+
+    datactx = *ctx;  /* print context  */
+    /* Assume entire data space to be printed */
+    datactx.need_prefix = TRUE;
+
+    nsize = H5Tget_size(f_type);
+
+    HDmemset(&buffer, 0, sizeof(h5tools_str_t));
+    for (i = 0; i < ndims; i++, datactx.cur_elmt++, elmt_counter++) {
+        void *memref = region_buf + i * nsize;
+
+        H5TOOLS_DEBUG("reference loop:%d with curr_pos=%ld", i, curr_pos);
+
+        datactx.need_prefix = TRUE;
+        h5tools_str_reset(&buffer);
+        H5TOOLS_DEBUG("reference loop - h5tools_str_sprint with H5T_STD_REF_DSETREG:%d", i);
+        h5tools_str_sprint(&buffer, info, container, f_type, memref, &datactx);
+        h5tools_render_element(stream, info, &datactx, &buffer, &curr_pos, (size_t)ncols, (hsize_t)i, (hsize_t)ndims);
+
+        if (!h5tools_is_zero(memref, H5Tget_size(f_type))) {
+            if (nsize == H5R_OBJ_REF_BUF_SIZE) {
+                if ((region_id = H5Rdereference2(container, H5P_DEFAULT, H5R_OBJECT, memref)) >= 0) {
+                    datactx.indent_level++;
+                    h5tools_dump_data(stream, info, &datactx, region_id, TRUE);
+                    datactx.indent_level--;
+                }
+            }
+            else {
+                if ((region_id = H5Rdereference2(container, H5P_DEFAULT, H5R_DATASET_REGION, memref)) >= 0) {
+                    if ((region_sid = H5Rget_region(container, H5R_DATASET_REGION, memref)) >= 0) {
+                        H5S_sel_type region_type;
+
+                        region_type = H5Sget_select_type(region_sid);
+                        if(region_type == H5S_SEL_POINTS) {
+                            /* Print point information */
+                            H5TOOLS_DEBUG("H5S_SEL_POINTS H5R_DATASET_REGION");
+                            h5tools_dump_region_data_points(
+                                    region_sid, region_id, stream, info, &datactx,
+                                                &buffer, &curr_pos, ncols, (hsize_t)i, elmt_counter);
+                        }
+                        else if(region_type == H5S_SEL_HYPERSLABS) {
+                            /* Print block information */
+                            H5TOOLS_DEBUG("H5S_SEL_HYPERSLABS H5R_DATASET_REGION");
+                            h5tools_dump_region_data_blocks(
+                                    region_sid, region_id, stream, info, &datactx,
+                                                &buffer, &curr_pos, ncols, (hsize_t)i, elmt_counter);
+                        }
+                        else
+                            H5TOOLS_INFO("invalid region type");
+                        if(H5Sclose(region_sid) < 0)
+                            H5TOOLS_INFO("H5Sclose H5R_DATASET_REGION failed");
+                    } /* end if (region_space >= 0) */
+                    else
+                        H5TOOLS_INFO("H5Rget_region H5R_DATASET_REGION failed");
+                    if(H5Dclose(region_id) < 0)
+                        H5TOOLS_INFO("H5Dclose H5R_DATASET_REGION failed");
+                } /* if (region_id >= 0) */
+                else {
+                    /* if (region_id < 0) - could mean that no reference was written do not throw failure */
+                    H5Epush2(H5tools_ERR_STACK_g, __FILE__, FUNC, __LINE__, H5tools_ERR_CLS_g, H5E_tools_g, H5E_tools_min_id_g, "H5Rdereference failed");
+                }
+            }
+        } /* end else to if (h5tools_is_zero(... */
+
+        H5TOOLS_DEBUG("finished reference loop:%d",i);
+    } /* end for(i = 0; i < ndims; i++, ctx->cur_elmt++, elmt_counter++) */
+
+    h5tools_str_close(&buffer);
+
+    H5TOOLS_ENDDEBUG("");
+}
+
+/*-------------------------------------------------------------------------
  * Function:    dump_data
  *
  * Purpose:     Dump attribute, obj_data is FALSE, or dataset data, obj_data is TRUE
@@ -3829,14 +4045,10 @@ h5tools_dump_data(FILE *stream, const h5tool_format_t *info, h5tools_context_t *
 {
     H5S_class_t        space_type;
     int                ndims;
-    size_t             i;
     size_t             nsize;
     hid_t              space = H5I_INVALID_HID;
     hid_t              f_type = H5I_INVALID_HID;
-    hid_t              region_id = H5I_INVALID_HID;
-    hid_t              region_space = H5I_INVALID_HID;
     hsize_t            total_size[H5S_MAX_RANK];
-    hsize_t            elmt_counter = 0;  /*counts the # elements printed. */
     int                status = -1;
     h5tools_context_t  datactx;            /* print context  */
     h5tools_str_t      buffer;          /* string into which to render   */
@@ -3903,13 +4115,9 @@ h5tools_dump_data(FILE *stream, const h5tool_format_t *info, h5tools_context_t *
         H5TOOLS_DEBUG("ndims=%d - datactx.ndims=%d", ndims, datactx.ndims);
 
         /* Assume entire data space to be printed */
-        if (datactx.ndims > 0)
-            for (i = 0; i < (size_t)datactx.ndims; i++)
-                datactx.p_min_idx[i] = 0;
-
         H5Sget_simple_extent_dims(space, total_size, NULL);
-        if (datactx.ndims > 0)
-            init_acc_pos(&datactx, total_size);
+        init_acc_pos(datactx.ndims, total_size, datactx.acc, datactx.pos, datactx.p_min_idx);
+
         datactx.need_prefix = TRUE;
 
         if (NULL != (region_buf = (void *)HDcalloc(nsize, (size_t)ndims))) {
@@ -3927,64 +4135,7 @@ h5tools_dump_data(FILE *stream, const h5tool_format_t *info, h5tools_context_t *
                     H5TOOLS_GOTO_DONE_NO_RET();
                 }
             }
-            for (i = 0; i < ndims; i++, datactx.cur_elmt++, elmt_counter++) {
-                void *memref = region_buf + i * nsize;
-
-                H5TOOLS_DEBUG("reference loop:%d with curr_pos=%ld", i, curr_pos);
-
-                datactx.need_prefix = TRUE;
-                h5tools_str_reset(&buffer);
-                H5TOOLS_DEBUG("reference loop - h5tools_str_sprint with H5T_STD_REF_DSETREG:%d", i);
-                h5tools_str_sprint(&buffer, &outputformat, obj_id, f_type, memref, &datactx);
-                h5tools_render_element(stream, &outputformat, &datactx, &buffer, &curr_pos, (size_t)ncols, (hsize_t)0, (hsize_t)0);
-
-                if (!h5tools_is_zero(memref, H5Tget_size(f_type))) {
-                    if (nsize == H5R_OBJ_REF_BUF_SIZE) {
-                        if ((region_id = H5Rdereference2(obj_id, H5P_DEFAULT, H5R_OBJECT, memref)) >= 0) {
-                            datactx.indent_level++;
-                            h5tools_dump_data(stream, &outputformat, &datactx, region_id, TRUE);
-                            datactx.indent_level--;
-                        }
-                    }
-                    else {
-                        if ((region_id = H5Rdereference2(obj_id, H5P_DEFAULT, H5R_DATASET_REGION, memref)) >= 0) {
-                            if ((region_space = H5Rget_region(obj_id, H5R_DATASET_REGION, memref)) >= 0) {
-                                H5S_sel_type region_type;
-
-                                region_type = H5Sget_select_type(region_space);
-                                if(region_type == H5S_SEL_POINTS) {
-                                    /* Print point information */
-                                    H5TOOLS_DEBUG("H5S_SEL_POINTS H5R_DATASET_REGION");
-                                    h5tools_dump_region_data_points(
-                                                           region_space, region_id, stream, &outputformat, &datactx,
-                                                           &buffer, &curr_pos, ncols, (hsize_t)i, elmt_counter);
-                                }
-                                else if(region_type == H5S_SEL_HYPERSLABS) {
-                                    /* Print block information */
-                                    H5TOOLS_DEBUG("H5S_SEL_HYPERSLABS H5R_DATASET_REGION");
-                                    h5tools_dump_region_data_blocks(
-                                                           region_space, region_id, stream, &outputformat, &datactx,
-                                                           &buffer, &curr_pos, ncols, (hsize_t)i, elmt_counter);
-                                }
-                                else
-                                    H5TOOLS_INFO("invalid region type");
-                                if(H5Sclose(region_space) < 0)
-                                    H5TOOLS_INFO("H5Sclose H5R_DATASET_REGION failed");
-                            } /* end if (region_space >= 0) */
-                            else
-                                H5TOOLS_INFO("H5Rget_region H5R_DATASET_REGION failed");
-                            if(H5Dclose(region_id) < 0)
-                                H5TOOLS_INFO("H5Dclose H5R_DATASET_REGION failed");
-                        } /* if (region_id >= 0) */
-                        else {
-                            /* if (region_id < 0) - could mean that no reference was written do not throw failure */
-                            H5Epush2(H5tools_ERR_STACK_g, __FILE__, FUNC, __LINE__, H5tools_ERR_CLS_g, H5E_tools_g, H5E_tools_min_id_g, "H5Rdereference failed");
-                        }
-                    }
-                } /* end else to if (h5tools_is_zero(... */
-
-                H5TOOLS_DEBUG("finished reference loop:%d",i);
-            } /* end for(i = 0; i < ndims; i++, datactx->cur_elmt++, elmt_counter++) */
+            h5tools_dump_reference(stream, &outputformat, &datactx, obj_id, f_type, region_buf, ndims);
             HDfree(region_buf);
         }
         ctx->indent_level--;
diff --git a/tools/lib/h5tools_dump.h b/tools/lib/h5tools_dump.h
index f2fdb4e..67c3e5f 100644
--- a/tools/lib/h5tools_dump.h
+++ b/tools/lib/h5tools_dump.h
@@ -36,56 +36,53 @@ H5TOOLS_DLLVAR table_t *h5dump_type_table;  /*type table reference for datatype
 /* Definitions of useful routines */
 H5TOOLS_DLL void    h5tools_dump_init(void);
 
-H5TOOLS_DLL int     h5tools_dump_dset(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, hid_t dset);
-H5TOOLS_DLL int     h5tools_dump_mem(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, hid_t obj_id);
-H5TOOLS_DLL int     h5tools_dump_simple_data(FILE *stream, const h5tool_format_t *info, hid_t container,
-                            h5tools_context_t *ctx/*in,out*/, unsigned flags,
-                            hsize_t nelmts, hid_t type, void *_mem);
-H5TOOLS_DLL void    h5tools_dump_datatype(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, hid_t type);
-H5TOOLS_DLL void    h5tools_dump_dataspace(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, hid_t space);
-H5TOOLS_DLL void    h5tools_dump_attribute(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, const char *attr_name, hid_t attr_id);
-H5TOOLS_DLL void    h5tools_dump_oid(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, hid_t oid);
-H5TOOLS_DLL void    h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, hid_t dcpl, hid_t type_id, hid_t obj_id);
-H5TOOLS_DLL void    h5tools_dump_comment(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/, hid_t obj_id);
-H5TOOLS_DLL void    h5tools_dump_data(FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx, hid_t obj_id, int obj_data);
+H5TOOLS_DLL int     h5tools_dump_dset(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t dset);
+H5TOOLS_DLL int     h5tools_dump_mem(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t obj_id);
+H5TOOLS_DLL int     h5tools_dump_simple_data(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t container, unsigned flags, hsize_t nelmts, hid_t type, void *_mem);
+H5TOOLS_DLL void    h5tools_dump_datatype(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t type);
+H5TOOLS_DLL void    h5tools_dump_dataspace(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t space);
+H5TOOLS_DLL void    h5tools_dump_attribute(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            const char *attr_name, hid_t attr_id);
+H5TOOLS_DLL void    h5tools_dump_oid(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t oid);
+H5TOOLS_DLL void    h5tools_dump_dcpl(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t dcpl, hid_t type_id, hid_t obj_id);
+H5TOOLS_DLL void    h5tools_dump_comment(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            hid_t obj_id);
+H5TOOLS_DLL void    h5tools_dump_data(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+                            hid_t obj_id, int obj_data);
+H5TOOLS_DLL void    h5tools_dump_reference(FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx,
+                            hid_t container, hid_t f_type, unsigned char *region_buf, int ndims);
+H5TOOLS_DLL hbool_t h5tools_dump_region_attribute(hid_t region_id,
+                            FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            h5tools_str_t *buffer, hsize_t *curr_pos, size_t ncols, hsize_t region_elmt_counter, hsize_t elmt_counter);
 
 H5TOOLS_DLL hbool_t h5tools_dump_region_data_points(hid_t region_space, hid_t region_id,
-                            FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/,
-                            h5tools_str_t *buffer/*string into which to render */,
-                            hsize_t *curr_pos/*total data element position*/,
-                            size_t ncols, hsize_t region_elmt_counter/*element counter*/,
-                            hsize_t elmt_counter);
+                            FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            h5tools_str_t *buffer, hsize_t *curr_pos, size_t ncols, hsize_t region_elmt_counter, hsize_t elmt_counter);
 
 H5TOOLS_DLL hbool_t h5tools_dump_region_data_blocks(hid_t region_space, hid_t region_id,
-                            FILE *stream, const h5tool_format_t *info,
-                            h5tools_context_t *ctx/*in,out*/,
-                            h5tools_str_t *buffer/*string into which to render */,
-                            hsize_t *curr_pos/*total data element position*/,
-                            size_t ncols, hsize_t region_elmt_counter/*element counter*/,
-                            hsize_t elmt_counter);
+                            FILE *stream, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+                            h5tools_str_t *buffer, hsize_t *curr_pos, size_t ncols, hsize_t region_elmt_counter, hsize_t elmt_counter);
 
-H5TOOLS_DLL int     h5tools_print_datatype(FILE *stream, h5tools_str_t *buffer/*in,out*/,
-                            const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+H5TOOLS_DLL int     h5tools_print_datatype(FILE *stream,
+                            h5tools_str_t *buffer/*in,out*/, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
                             hid_t type, int object_search);
 H5TOOLS_DLL int     h5tools_print_dataspace(h5tools_str_t *buffer/*in,out*/,
                             hid_t space);
-H5TOOLS_DLL int     h5tools_print_enum(FILE *stream, h5tools_str_t *buffer/*in,out*/,
-                            const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+H5TOOLS_DLL int     h5tools_print_enum(FILE *stream,
+                            h5tools_str_t *buffer/*in,out*/, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
                             hid_t type);
-H5TOOLS_DLL void    h5tools_print_fill_value(h5tools_str_t *buffer/*in,out*/,
-                            const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
+H5TOOLS_DLL void    h5tools_print_fill_value(
+                            h5tools_str_t *buffer/*in,out*/, const h5tool_format_t *info, h5tools_context_t *ctx/*in,out*/,
                             hid_t dcpl, hid_t type_id, hid_t obj_id);
 H5TOOLS_DLL void    h5tools_print_packed_bits(h5tools_str_t *buffer/*in,out*/, hid_t type);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/tools/lib/h5tools_error.h b/tools/lib/h5tools_error.h
index 4e2e935..764fb91 100644
--- a/tools/lib/h5tools_error.h
+++ b/tools/lib/h5tools_error.h
@@ -101,14 +101,16 @@ do {
  * H5TOOLS_PUSH_ERROR macro, used to push an error to an error stack. Not meant to
  * be called directly.
  */
-#define H5TOOLS_PUSH_ERROR(estack_id, err_cls, maj_err_id, min_err_id, ...)                          \
-do {                                                                                                 \
-    if (estack_id >= 0 && err_cls >= 0)                                                              \
-        H5Epush2(estack_id, __FILE__, FUNC, __LINE__, err_cls, maj_err_id, min_err_id, __VA_ARGS__); \
-    else {                                                                                           \
-        HDfprintf(stderr, __VA_ARGS__);                                                              \
-        HDfprintf(stderr, "\n");                                                                     \
-    }                                                                                                \
+#define H5TOOLS_PUSH_ERROR(estack_id, err_cls, maj_err_id, min_err_id, ...)                              \
+do {                                                                                                     \
+    if (enable_error_stack > 0) {                                                                        \
+        if (estack_id >= 0 && err_cls >= 0)                                                              \
+            H5Epush2(estack_id, __FILE__, FUNC, __LINE__, err_cls, maj_err_id, min_err_id, __VA_ARGS__); \
+        else {                                                                                           \
+            HDfprintf(stderr, __VA_ARGS__);                                                              \
+            HDfprintf(stderr, "\n");                                                                     \
+        }                                                                                                \
+    }                                                                                                    \
 } while(0)
 
 /*
@@ -167,30 +169,30 @@ do {
 
 #ifdef H5_TOOLS_DEBUG
 
-#define H5TOOLS_START_DEBUG(...)                                                                 \
-do {                                                                                             \
-    H5tools_INDENT_g += 2;                                                                       \
+#define H5TOOLS_START_DEBUG(...)                                                                     \
+do {                                                                                                 \
+    H5tools_INDENT_g += 2;                                                                           \
     HDfprintf(stderr, "%*sENTER %s:%d in %s()...", H5tools_INDENT_g, "", __FILE__, __LINE__, FUNC);  \
-    HDfprintf(stderr, __VA_ARGS__);                                                              \
-    HDfprintf(stderr, "\n");                                                                     \
-    HDfflush(stderr);                                                                            \
+    HDfprintf(stderr, __VA_ARGS__);                                                                  \
+    HDfprintf(stderr, "\n");                                                                         \
+    HDfflush(stderr);                                                                                \
 } while(0)
 
-#define H5TOOLS_DEBUG(...)                                                                       \
-do {                                                                                             \
+#define H5TOOLS_DEBUG(...)                                                                           \
+do {                                                                                                 \
     HDfprintf(stderr, "%*s %s:%d in %s()...", H5tools_INDENT_g, "", __FILE__, __LINE__, FUNC);       \
-    HDfprintf(stderr, __VA_ARGS__);                                                              \
-    HDfprintf(stderr, "\n");                                                                     \
-    HDfflush(stderr);                                                                            \
+    HDfprintf(stderr, __VA_ARGS__);                                                                  \
+    HDfprintf(stderr, "\n");                                                                         \
+    HDfflush(stderr);                                                                                \
 } while(0)
 
-#define H5TOOLS_ENDDEBUG(...)                                                                    \
-do {                                                                                             \
+#define H5TOOLS_ENDDEBUG(...)                                                                        \
+do {                                                                                                 \
     HDfprintf(stderr, "%*sEXIT %s:%d in %s()...", H5tools_INDENT_g, "", __FILE__, __LINE__, FUNC);   \
-    HDfprintf(stderr, __VA_ARGS__);                                                              \
-    HDfprintf(stderr, "\n");                                                                     \
-    H5tools_INDENT_g -= 2;                                                                       \
-    HDfflush(stderr);                                                                            \
+    HDfprintf(stderr, __VA_ARGS__);                                                                  \
+    HDfprintf(stderr, "\n");                                                                         \
+    H5tools_INDENT_g -= 2;                                                                           \
+    HDfflush(stderr);                                                                                \
 } while(0)
 
 #else
diff --git a/tools/lib/h5tools_str.c b/tools/lib/h5tools_str.c
index 798c025..3843ee4 100644
--- a/tools/lib/h5tools_str.c
+++ b/tools/lib/h5tools_str.c
@@ -278,16 +278,12 @@ h5tools_str_fmt(h5tools_str_t *str/*in,out*/, size_t start, const char *fmt)
  * Purpose: Renders the line prefix value into string STR.
  *
  * Return:  Success:    Pointer to the prefix.
- *
  *          Failure:    NULL
- *
- * Programmer:  Robb Matzke
- *              Thursday, July 23, 1998
  *-------------------------------------------------------------------------
  */
 char *
-h5tools_str_prefix(h5tools_str_t *str/*in,out*/, const h5tool_format_t *info,
-    hsize_t elmtno, unsigned ndims, h5tools_context_t *ctx)
+h5tools_str_prefix(h5tools_str_t *str/*in,out*/, const h5tool_format_t *info, hsize_t elmtno,
+        h5tools_context_t *ctx)
 {
     size_t    i = 0;
     hsize_t   curr_pos = elmtno;
@@ -297,28 +293,16 @@ h5tools_str_prefix(h5tools_str_t *str/*in,out*/, const h5tool_format_t *info,
     H5TOOLS_DEBUG("elmtno=%ld, ctx->ndims=%d", elmtno, ctx->ndims);
     h5tools_str_reset(str);
 
-    H5TOOLS_DEBUG("ndims=%d", ndims);
-    if(ndims > 0) {
-        /*
-         * Calculate the number of elements represented by a unit change in a
-         * certain index position.
-         */
-        for(i = 0; i < (size_t) ndims; i++) {
-            H5TOOLS_DEBUG("curr_pos=%ld - ctx->acc[%d]=%ld", curr_pos, i, ctx->acc[i]);
-            ctx->pos[i] = curr_pos / ctx->acc[i];
-            curr_pos -= ctx->acc[i] * ctx->pos[i];
-            H5TOOLS_DEBUG("curr_pos=%ld - ctx->pos[%d]=%ld - ctx->acc[%d]=%ld", curr_pos, i, ctx->pos[i], i, ctx->acc[i]);
-        }
+    curr_pos = calc_acc_pos(ctx->ndims, elmtno, ctx->acc, ctx->pos);
+    if(ctx->ndims > 0) {
         HDassert(curr_pos == 0);
 
         /* Print the index values */
-        for(i = 0; i < (size_t) ndims; i++) {
+        for(i = 0; i < (size_t) ctx->ndims; i++) {
             if (i)
                 h5tools_str_append(str, "%s", OPT(info->idx_sep, ","));
 
-            h5tools_str_append(str, OPT(info->idx_n_fmt, HSIZE_T_FORMAT),
-                    (hsize_t) ctx->pos[i]);
-
+            h5tools_str_append(str, OPT(info->idx_n_fmt, HSIZE_T_FORMAT), (hsize_t) ctx->pos[i]);
         }
     }
     else        /* Scalar */
@@ -338,52 +322,38 @@ h5tools_str_prefix(h5tools_str_t *str/*in,out*/, const h5tool_format_t *info,
  *
  * Return:  Success:    Pointer to the prefix.
  *          Failure:    NULL
- *
- * In/Out:
- *      h5tools_context_t *ctx
- *      h5tools_str_t     *str
  *-------------------------------------------------------------------------
  */
 char *
-h5tools_str_region_prefix(h5tools_str_t *str, const h5tool_format_t *info,
-        hsize_t elmtno, hsize_t *ptdata, unsigned ndims, hsize_t max_idx[],
-        h5tools_context_t *ctx)
+h5tools_str_region_prefix(h5tools_str_t *str/*in,out*/, const h5tool_format_t *info, hsize_t elmtno,
+        hsize_t *ptdata, h5tools_context_t *ctx)
 {
     size_t    i = 0;
     hsize_t   curr_pos = elmtno;
-    hsize_t   p_prod[H5S_MAX_RANK];
 
-    h5tools_str_reset(str);
+    H5TOOLS_START_DEBUG("");
 
-    if(ndims > 0) {
-        /*
-         * Calculate the number of elements represented by a unit change in a
-         * certain index position.
-         */
-        for(i = ndims - 1, p_prod[ndims - 1] = 1; i > 0; --i)
-            p_prod[i - 1] = (max_idx[i]) * p_prod[i];
+    H5TOOLS_DEBUG("elmtno=%ld, ctx->ndims=%d", elmtno, ctx->ndims);
+    h5tools_str_reset(str);
 
-        for(i = 0; i < (size_t) ndims; i++) {
-            if(curr_pos > 0) {
-                ctx->pos[i] = curr_pos / p_prod[i];
-                curr_pos -= p_prod[i] * ctx->pos[i];
-            }
-            else
-                ctx->pos[i] = 0;
-            ctx->pos[i] += (unsigned long) ptdata[ctx->sm_pos+i];
-        }
+    curr_pos = calc_acc_pos(ctx->ndims, elmtno, ctx->acc, ctx->pos);
+    if(ctx->ndims > 0) {
+        HDassert(curr_pos == 0);
 
         /* Print the index values */
-        for(i = 0; i < (size_t) ndims; i++) {
-            if(i)
+        for(i = 0; i < (size_t) ctx->ndims; i++) {
+            ctx->pos[i] += (unsigned long) ptdata[ctx->sm_pos+i];
+            if (i)
                 h5tools_str_append(str, "%s", OPT(info->idx_sep, ","));
 
             h5tools_str_append(str, OPT(info->idx_n_fmt, HSIZE_T_FORMAT), (hsize_t) ctx->pos[i]);
-
         }
-    } /* if (ndims > 0) */
+    }
     else        /* Scalar */
-        h5tools_str_append(str, OPT(info->idx_n_fmt, HSIZE_T_FORMAT), (hsize_t) 0);
+        h5tools_str_append(str, OPT(info->idx_n_fmt, HSIZE_T_FORMAT), (hsize_t)0);
+    H5TOOLS_DEBUG("str=%s", str->s);
+
+    H5TOOLS_ENDDEBUG("");
 
     /* Add prefix and suffix to the index */
     return h5tools_str_fmt(str, (size_t)0, OPT(info->idx_fmt, "%s: "));
@@ -1276,7 +1246,6 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
                 break;
         } /* end switch */
     }
-    H5TOOLS_DEBUG("switch done");
 
     ret_value = h5tools_str_fmt(str, start, OPT(info->elmt_fmt, "%s"));
 
diff --git a/tools/lib/h5tools_str.h b/tools/lib/h5tools_str.h
index 3f922bb..d27aa95 100644
--- a/tools/lib/h5tools_str.h
+++ b/tools/lib/h5tools_str.h
@@ -31,13 +31,12 @@ H5TOOLS_DLL char    *h5tools_str_reset(h5tools_str_t *str);
 H5TOOLS_DLL char    *h5tools_str_trunc(h5tools_str_t *str, size_t size);
 H5TOOLS_DLL char    *h5tools_str_fmt(h5tools_str_t *str, size_t start, const char *fmt);
 H5TOOLS_DLL char    *h5tools_str_prefix(h5tools_str_t *str, const h5tool_format_t *info,
-                        hsize_t elmtno, unsigned ndims, h5tools_context_t *ctx);
+                        hsize_t elmtno, h5tools_context_t *ctx);
 /*
  * new functions needed to display region reference data
  */
 H5TOOLS_DLL char    *h5tools_str_region_prefix(h5tools_str_t *str, const h5tool_format_t *info,
-                                   hsize_t elmtno, hsize_t *ptdata, unsigned ndims,
-                                   hsize_t max_idx[], h5tools_context_t *ctx);
+                                   hsize_t elmtno, hsize_t *ptdata, h5tools_context_t *ctx);
 H5TOOLS_DLL void     h5tools_str_dump_space_slabs(h5tools_str_t *, hid_t, const h5tool_format_t *, h5tools_context_t *ctx);
 H5TOOLS_DLL void     h5tools_str_dump_space_blocks(h5tools_str_t *, hid_t, const h5tool_format_t *);
 H5TOOLS_DLL void     h5tools_str_dump_space_points(h5tools_str_t *, hid_t, const h5tool_format_t *);
diff --git a/tools/lib/h5tools_utils.c b/tools/lib/h5tools_utils.c
index 8de7f80..27c5ad1 100644
--- a/tools/lib/h5tools_utils.c
+++ b/tools/lib/h5tools_utils.c
@@ -1048,7 +1048,7 @@ h5tools_getenv_update_hyperslab_bufsize(void)
 {
     const char *env_str = NULL;
     long hyperslab_bufsize_mb;
-    int ret_value = 1;
+    int  ret_value = 1;
 
     /* check if environment variable is set for the hyperslab buffer size */
     if (NULL != (env_str = HDgetenv ("H5TOOLS_BUFSIZE"))) {
@@ -1067,6 +1067,55 @@ done:
     return ret_value;
 }
 
+#ifdef H5_HAVE_ROS3_VFD
+/*----------------------------------------------------------------------------
+ *
+ * Function: h5tools_parse_ros3_fapl_tuple
+ *
+ * Purpose:  A convenience function that parses a string containing a tuple
+ *           of S3 VFD credential information and then passes the result to
+ *           `h5tools_populate_ros3_fapl()` in order to setup a valid
+ *           configuration for the S3 VFD.
+ *
+ * Return:   SUCCEED/FAIL
+ *
+ *----------------------------------------------------------------------------
+ */
+herr_t
+h5tools_parse_ros3_fapl_tuple(const char *tuple_str, int delim,
+    H5FD_ros3_fapl_t *fapl_config_out)
+{
+    const char  *ccred[3];
+    unsigned     nelems     = 0;
+    char        *start      = NULL;
+    char        *s3cred_src = NULL;
+    char       **s3cred     = NULL;
+    herr_t       ret_value  = SUCCEED;
+
+    /* Attempt to parse S3 credentials tuple */
+    if (parse_tuple(tuple_str, delim, &s3cred_src, &nelems, &s3cred) < 0)
+        H5TOOLS_GOTO_ERROR(FAIL, "failed to parse S3 VFD info tuple");
+
+    /* Sanity-check tuple count */
+    if (nelems != 3)
+        H5TOOLS_GOTO_ERROR(FAIL, "invalid S3 VFD credentials");
+
+    ccred[0] = (const char *)s3cred[0];
+    ccred[1] = (const char *)s3cred[1];
+    ccred[2] = (const char *)s3cred[2];
+
+    if (0 == h5tools_populate_ros3_fapl(fapl_config_out, ccred))
+        H5TOOLS_GOTO_ERROR(FAIL, "failed to populate S3 VFD FAPL config");
+
+done:
+    if (s3cred)
+        HDfree(s3cred);
+    if (s3cred_src)
+        HDfree(s3cred_src);
+
+    return ret_value;
+}
+
 
 /*----------------------------------------------------------------------------
  *
@@ -1130,7 +1179,6 @@ done:
  *
  *----------------------------------------------------------------------------
  */
-#ifdef H5_HAVE_ROS3_VFD
 int
 h5tools_populate_ros3_fapl(H5FD_ros3_fapl_t  *fa,
                            const char       **values)
@@ -1254,73 +1302,72 @@ h5tools_populate_ros3_fapl(H5FD_ros3_fapl_t  *fa,
 
 done:
     return ret_value;
-
 } /* h5tools_populate_ros3_fapl */
 #endif /* H5_HAVE_ROS3_VFD */
 
-
-/*-----------------------------------------------------------------------------
- *
- * Function: h5tools_set_configured_fapl
- *
- * Purpose: prepare fapl_id with the given property list, according to
- *          VFD prototype.
+#ifdef H5_HAVE_LIBHDFS
+/*----------------------------------------------------------------------------
  *
- * Return: 0 on failure, 1 on success
+ * Function: h5tools_parse_hdfs_fapl_tuple
  *
- * Programmer: Jacob Smith
- *             2018-05-21
+ * Purpose:  A convenience function that parses a string containing a tuple
+ *           of HDFS VFD configuration information.
  *
- * Changes: None.
+ * Return:   SUCCEED/FAIL
  *
- *-----------------------------------------------------------------------------
+ *----------------------------------------------------------------------------
  */
-int
-h5tools_set_configured_fapl(hid_t      fapl_id,
-                           const char  vfd_name[],
-                           void       *fapl_t_ptr)
+herr_t
+h5tools_parse_hdfs_fapl_tuple(const char *tuple_str, int delim,
+    H5FD_hdfs_fapl_t *fapl_config_out)
 {
-    int ret_value = 1;
-
-    if (fapl_id < 0) {
-        return 0;
+    unsigned long   k         = 0;
+    unsigned        nelems    = 0;
+    char           *props_src = NULL;
+    char          **props     = NULL;
+    herr_t          ret_value = SUCCEED;
+
+    /* Attempt to parse HDFS configuration tuple */
+    if (parse_tuple(tuple_str, delim, &props_src, &nelems, &props) < 0)
+        H5TOOLS_GOTO_ERROR(FAIL, "failed to parse HDFS VFD configuration tuple");
+
+    /* Sanity-check tuple count */
+    if (nelems != 5)
+        H5TOOLS_GOTO_ERROR(FAIL, "invalid HDFS VFD configuration");
+
+    /* Populate fapl configuration structure with given properties.
+     * WARNING: No error-checking is done on length of input strings...
+     *          Silent overflow is possible, albeit unlikely.
+     */
+    if (HDstrncmp(props[0], "", 1)) {
+        HDstrncpy(fapl_config_out->namenode_name, (const char *)props[0], HDstrlen(props[0]));
     }
-
-    if (!strcmp("", vfd_name)) {
-        goto done;
-
-#ifdef H5_HAVE_ROS3_VFD
-    } else if (!strcmp("ros3", vfd_name)) {
-        if ((fapl_id == H5P_DEFAULT) ||
-            (fapl_t_ptr == NULL) ||
-            (FAIL == H5Pset_fapl_ros3(
-                fapl_id,
-                (H5FD_ros3_fapl_t *)fapl_t_ptr)))
-        {
-            ret_value = 0;
-            goto done;
-        }
-#endif /* H5_HAVE_ROS3_VFD */
-
-#ifdef H5_HAVE_LIBHDFS
-    } else if (!strcmp("hdfs", vfd_name)) {
-        if ((fapl_id == H5P_DEFAULT) ||
-            (fapl_t_ptr == NULL) ||
-            (FAIL == H5Pset_fapl_hdfs(
-                fapl_id,
-                (H5FD_hdfs_fapl_t *)fapl_t_ptr)))
-        {
-            ret_value = 0;
-            goto done;
-        }
-#endif /* H5_HAVE_LIBHDFS */
-
-    } else {
-        ret_value = 0; /* unrecognized fapl type "name" */
+    if (HDstrncmp(props[1], "", 1)) {
+        k = strtoul((const char *)props[1], NULL, 0);
+        if (errno == ERANGE)
+            H5TOOLS_GOTO_ERROR(FAIL, "supposed port number wasn't");
+        fapl_config_out->namenode_port = (int32_t)k;
+    }
+    if (HDstrncmp(props[2], "", 1)) {
+        HDstrncpy(fapl_config_out->kerberos_ticket_cache, (const char *)props[2], HDstrlen(props[2]));
+    }
+    if (HDstrncmp(props[3], "", 1)) {
+        HDstrncpy(fapl_config_out->user_name, (const char *)props[3], HDstrlen(props[3]));
+    }
+    if (HDstrncmp(props[4], "", 1)) {
+        k = HDstrtoul((const char *)props[4], NULL, 0);
+        if (errno == ERANGE)
+            H5TOOLS_GOTO_ERROR(FAIL, "supposed buffersize number wasn't");
+        fapl_config_out->stream_buffer_size = (int32_t)k;
     }
 
 done:
-    return ret_value;
+    if (props)
+        HDfree(props);
+    if (props_src)
+        HDfree(props_src);
 
-} /* h5tools_set_configured_fapl() */
+    return ret_value;
+}
+#endif /* H5_HAVE_LIBHDFS */
 
diff --git a/tools/lib/h5tools_utils.h b/tools/lib/h5tools_utils.h
index 812854f..5daa5d2 100644
--- a/tools/lib/h5tools_utils.h
+++ b/tools/lib/h5tools_utils.h
@@ -172,10 +172,15 @@ H5TOOLS_DLL void h5tools_setprogname(const char*progname);
 H5TOOLS_DLL int h5tools_getstatus(void);
 H5TOOLS_DLL void h5tools_setstatus(int d_status);
 H5TOOLS_DLL int h5tools_getenv_update_hyperslab_bufsize(void);
-H5TOOLS_DLL int h5tools_set_configured_fapl(hid_t fapl_id, const char vfd_name[], void *fapl_t_ptr);
 #ifdef H5_HAVE_ROS3_VFD
+H5TOOLS_DLL herr_t h5tools_parse_ros3_fapl_tuple(const char *tuple_str, int delim,
+    H5FD_ros3_fapl_t *fapl_config_out);
 H5TOOLS_DLL int h5tools_populate_ros3_fapl(H5FD_ros3_fapl_t *fa, const char **values);
 #endif /* H5_HAVE_ROS3_VFD */
+#ifdef H5_HAVE_LIBHDFS
+H5TOOLS_DLL herr_t h5tools_parse_hdfs_fapl_tuple(const char *tuple_str, int delim,
+    H5FD_hdfs_fapl_t *fapl_config_out);
+#endif
 
 #ifdef __cplusplus
 }
diff --git a/tools/lib/io_timer.c b/tools/lib/io_timer.c
index 472824b..5c0c31d 100644
--- a/tools/lib/io_timer.c
+++ b/tools/lib/io_timer.c
@@ -23,7 +23,6 @@
  */
 
 #include "H5private.h"
-#include "hdf5.h"
 
 #include "io_timer.h"