[svn-r8425] Purpose:

    Bug fix (sorta)

Description:
    The SGI machines have problems accurately (and consistently) converting
unsigned long values to float and double values, so put in a bit of a hack in
the datatype conversion test code to allow them to get "close enough".  This
hack is enabled at configure time by a flag which should only be set on machines
with this problem.

Platforms tested:
    FreeBSD 4.9 (sleipnir)
    h5committest

6 files changed, 85 insertions, 24 deletions

diff --git a/config/irix6.x b/config/irix6.x
index 57cf186..dcdf91e 100644
--- a/config/irix6.x
+++ b/config/irix6.x
@@ -140,3 +140,8 @@ if test -z "$cxx_flags_set"; then
   PROFILE_CPPFLAGS=
   cxx_flags_set=yes
 fi
+
+# Hard set flag to indicate that the 'unsigned long long' to floating-point
+# value conversion are broken by the compilers (as of 4/27/04 - QAK)
+hdf5_cv_sw_ulong_to_fp_bottom_bit_works=${hdf5_cv_sw_ulong_to_fp_bottom_bit_works='no'}
+
diff --git a/configure b/configure
index aed1b1b..b2efb89 100755
--- a/configure
+++ b/configure
@@ -33263,6 +33263,28 @@ else
 echo "${ECHO_T}no" >&6
 fi
 
+echo "$as_me:$LINENO: checking if accurately converting unsigned long long to floating-point values works" >&5
+echo $ECHO_N "checking if accurately converting unsigned long long to floating-point values works... $ECHO_C" >&6
+if test "${hdf5_cv_sw_ulong_to_fp_bottom_bit_works+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  hdf5_cv_sw_ulong_to_fp_bottom_bit_works=yes
+fi
+
+
+if test ${hdf5_cv_sw_ulong_to_fp_bottom_bit_works} = "yes"; then
+
+cat >>confdefs.h <<\_ACEOF
+#define SW_ULONG_TO_FP_BOTTOM_BIT_WORKS 1
+_ACEOF
+
+  echo "$as_me:$LINENO: result: yes" >&5
+echo "${ECHO_T}yes" >&6
+else
+  echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6
+fi
+
 
 H5_VERSION="`cut -d' ' -f3 $srcdir/README.txt | head -1`"
 
diff --git a/configure.in b/configure.in
index 2b1a52f..dee22c2 100644
--- a/configure.in
+++ b/configure.in
@@ -2381,6 +2381,23 @@ else
 fi
 
 dnl ----------------------------------------------------------------------
+dnl Set the flag to indicate that the machine can accurately convert
+dnl 'unsigned long long' values to 'float' and 'double' values.
+dnl (This flag should be set for all machines, except for the SGIs, where
+dnl the cache value is set in the config/irix6.x config file)
+dnl
+AC_MSG_CHECKING([if accurately converting unsigned long long to floating-point values works])
+AC_CACHE_VAL([hdf5_cv_sw_ulong_to_fp_bottom_bit_works], [hdf5_cv_sw_ulong_to_fp_bottom_bit_works=yes])
+
+if test ${hdf5_cv_sw_ulong_to_fp_bottom_bit_works} = "yes"; then
+  AC_DEFINE([SW_ULONG_TO_FP_BOTTOM_BIT_WORKS], [1],
+            [Define if your system can accurately convert unsigned long long values to floating-point values.])
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
+fi
+
+dnl ----------------------------------------------------------------------
 dnl Set some variables for general configuration information to be saved
 dnl and installed with the libraries.
 dnl
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 78744d5..156e359 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -9369,9 +9369,9 @@ H5T_conv_i_f (hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, hsize_t nelmts,
 		     */
 			
                     /* Check 1st dropoff bit, see if it's set. */
-                    if(H5T_bit_get_d(int_buf, (first-dst.u.f.msize-1), 1)) {
+                    if(H5T_bit_get_d(int_buf, ((first-dst.u.f.msize)-1), 1)) {
                     	/* Check all bits after 1st dropoff bit, see if any of them is set. */
-                        if((first-dst.u.f.msize-1) > 0 && H5T_bit_get_d(int_buf, 0, (first-dst.u.f.msize-1)))
+                        if(((first-dst.u.f.msize)-1) > 0 && H5T_bit_get_d(int_buf, 0, ((first-dst.u.f.msize)-1)))
                             do_round = 1;
                         else {  /* The .50...0 case */
                             /* Check if the least significant bit is odd. */
diff --git a/src/H5config.h.in b/src/H5config.h.in
index 3a2924c..dffdb8a 100644
--- a/src/H5config.h.in
+++ b/src/H5config.h.in
@@ -501,6 +501,10 @@
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
+/* Define if your system can accurately convert unsigned long long values to
+   floating-point values. */
+#undef SW_ULONG_TO_FP_BOTTOM_BIT_WORKS
+
 /* Define if your system supports pthread_attr_setscope(&attribute,
    PTHREAD_SCOPE_SYSTEM) call. */
 #undef SYSTEM_SCOPE_THREADS
diff --git a/test/dtypes.c b/test/dtypes.c
index 27b4874..7e0b71b 100644
--- a/test/dtypes.c
+++ b/test/dtypes.c
@@ -4494,6 +4494,35 @@ test_conv_int_float(const char *name, hid_t src, hid_t dst)
                     }
                 }
             }
+/* On some machines (notably the SGI machines) unsigned long values
+ * are not converted to float or double values correctly, they are
+ * consistently off by the lowest bit being rounded oppositely to our
+ * software conversion routines output.  So, on those machines, we allow
+ * the converted value to be +/- 1 from the machine's value.  -QAK
+ */
+#ifndef H5_SW_ULONG_TO_FP_BOTTOM_BIT_WORKS
+            if(dst_size==sizeof(unsigned)) {
+                unsigned tmp_s, tmp_h;
+                HDmemcpy(&tmp_s,&buf[j*dst_size],sizeof(unsigned));
+                HDmemcpy(&tmp_h,&hw[0],sizeof(unsigned));
+                if((tmp_s+1)==tmp_h || (tmp_s-1)==tmp_h)
+                    continue; /*no error*/
+            } /* end if */
+            else if (dst_size==sizeof(unsigned long)) {
+                unsigned long tmp_s, tmp_h;
+                HDmemcpy(&tmp_s,&buf[j*dst_size],sizeof(unsigned long));
+                HDmemcpy(&tmp_h,&hw[0],sizeof(unsigned long));
+                if((tmp_s+1)==tmp_h || (tmp_s-1)==tmp_h)
+                    continue; /*no error*/
+            } /* end if */
+            else if (dst_size==sizeof(unsigned long long)) {
+                unsigned long long tmp_s, tmp_h;
+                HDmemcpy(&tmp_s,&buf[j*dst_size],sizeof(unsigned long long));
+                HDmemcpy(&tmp_h,&hw[0],sizeof(unsigned long long));
+                if((tmp_s+1)==tmp_h || (tmp_s-1)==tmp_h)
+                    continue; /*no error*/
+            } /* end if */
+#endif /* end H5_ULONG_FP_BOTTOM_BIT_WORKS */
 
 	    /* Print errors */
 	    if (0==fails_this_test++)
@@ -5546,26 +5575,16 @@ run_int_float_conv(const char *name)
     nerrors += test_conv_int_float(name, H5T_NATIVE_LONG, H5T_NATIVE_FLOAT);
     nerrors += test_conv_int_float(name, H5T_NATIVE_LONG, H5T_NATIVE_DOUBLE);
 
-    /* Temporarily disable these tests for software conversion.  They fail on 
-     * some systems(like modi4, premium, o2 and arabica)
-     */
-    if(!strcmp(name, "hw")) {
-        nerrors += test_conv_int_float(name, H5T_NATIVE_ULONG, H5T_NATIVE_FLOAT);
-        nerrors += test_conv_int_float(name, H5T_NATIVE_ULONG, H5T_NATIVE_DOUBLE);
-    }
+    nerrors += test_conv_int_float(name, H5T_NATIVE_ULONG, H5T_NATIVE_FLOAT);
+    nerrors += test_conv_int_float(name, H5T_NATIVE_ULONG, H5T_NATIVE_DOUBLE);
 #endif
 
 #if H5_SIZEOF_LONG_LONG!=H5_SIZEOF_LONG
     nerrors += test_conv_int_float(name, H5T_NATIVE_LLONG, H5T_NATIVE_FLOAT);
     nerrors += test_conv_int_float(name, H5T_NATIVE_LLONG, H5T_NATIVE_DOUBLE);
 
-    /* Temporarily disable these tests for software conversion.  They fail on 
-     * some systems(like modi4, premium, o2 and arabica)
-     */
-    if(!strcmp(name, "hw")) {
-        nerrors += test_conv_int_float(name, H5T_NATIVE_ULLONG, H5T_NATIVE_FLOAT);
-        nerrors += test_conv_int_float(name, H5T_NATIVE_ULLONG, H5T_NATIVE_DOUBLE);
-    }
+    nerrors += test_conv_int_float(name, H5T_NATIVE_ULLONG, H5T_NATIVE_FLOAT);
+    nerrors += test_conv_int_float(name, H5T_NATIVE_ULLONG, H5T_NATIVE_DOUBLE);
 #endif
 
     return nerrors;
@@ -5621,14 +5640,8 @@ run_float_int_conv(const char *name)
     nerrors += test_conv_int_float(name, H5T_NATIVE_FLOAT, H5T_NATIVE_LLONG);
     nerrors += test_conv_int_float(name, H5T_NATIVE_DOUBLE, H5T_NATIVE_LLONG);
 
-    /* Temporarily disable these two tests for software conversion because of 
-     * the bug in pgcc compiler.
-     * Will turn it back once the problem is solved.
-     */
-    if(!strcmp(name, "hw")) {
-        nerrors += test_conv_int_float(name, H5T_NATIVE_FLOAT, H5T_NATIVE_ULLONG);
-        nerrors += test_conv_int_float(name, H5T_NATIVE_DOUBLE, H5T_NATIVE_ULLONG);
-    }
+    nerrors += test_conv_int_float(name, H5T_NATIVE_FLOAT, H5T_NATIVE_ULLONG);
+    nerrors += test_conv_int_float(name, H5T_NATIVE_DOUBLE, H5T_NATIVE_ULLONG);
 #endif
     
     return nerrors;