Assume C99 fixed sized ints exist, use them (#470)

* Committing clang-format changes

* Assume C99 fixed sized ints exist, use them

* Assume H5_SIZEOF_LONG_DOUBLE != 0, `long double` has existed since C89

Note, this is only assuming that `long double` exists, no assumptions about its size have been touched.  Didn't remove any code that does things like test if `long double` and `double` have different sizes.

* Committing clang-format changes

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

27 files changed, 199 insertions, 506 deletions

diff --git a/c++/src/H5PredType.cpp b/c++/src/H5PredType.cpp
index 72d560d..c407c33 100644
--- a/c++/src/H5PredType.cpp
+++ b/c++/src/H5PredType.cpp
@@ -406,31 +406,29 @@ PredType::makePredTypes()
     MIPS_F32_ = new PredType(H5T_MIPS_F32);
     MIPS_F64_ = new PredType(H5T_MIPS_F64);
 
-    NATIVE_CHAR_   = new PredType(H5T_NATIVE_CHAR);
-    NATIVE_INT_    = new PredType(H5T_NATIVE_INT);
-    NATIVE_FLOAT_  = new PredType(H5T_NATIVE_FLOAT);
-    NATIVE_SCHAR_  = new PredType(H5T_NATIVE_SCHAR);
-    NATIVE_UCHAR_  = new PredType(H5T_NATIVE_UCHAR);
-    NATIVE_SHORT_  = new PredType(H5T_NATIVE_SHORT);
-    NATIVE_USHORT_ = new PredType(H5T_NATIVE_USHORT);
-    NATIVE_UINT_   = new PredType(H5T_NATIVE_UINT);
-    NATIVE_LONG_   = new PredType(H5T_NATIVE_LONG);
-    NATIVE_ULONG_  = new PredType(H5T_NATIVE_ULONG);
-    NATIVE_LLONG_  = new PredType(H5T_NATIVE_LLONG);
-    NATIVE_ULLONG_ = new PredType(H5T_NATIVE_ULLONG);
-    NATIVE_DOUBLE_ = new PredType(H5T_NATIVE_DOUBLE);
-#if H5_SIZEOF_LONG_DOUBLE != 0
+    NATIVE_CHAR_    = new PredType(H5T_NATIVE_CHAR);
+    NATIVE_INT_     = new PredType(H5T_NATIVE_INT);
+    NATIVE_FLOAT_   = new PredType(H5T_NATIVE_FLOAT);
+    NATIVE_SCHAR_   = new PredType(H5T_NATIVE_SCHAR);
+    NATIVE_UCHAR_   = new PredType(H5T_NATIVE_UCHAR);
+    NATIVE_SHORT_   = new PredType(H5T_NATIVE_SHORT);
+    NATIVE_USHORT_  = new PredType(H5T_NATIVE_USHORT);
+    NATIVE_UINT_    = new PredType(H5T_NATIVE_UINT);
+    NATIVE_LONG_    = new PredType(H5T_NATIVE_LONG);
+    NATIVE_ULONG_   = new PredType(H5T_NATIVE_ULONG);
+    NATIVE_LLONG_   = new PredType(H5T_NATIVE_LLONG);
+    NATIVE_ULLONG_  = new PredType(H5T_NATIVE_ULLONG);
+    NATIVE_DOUBLE_  = new PredType(H5T_NATIVE_DOUBLE);
     NATIVE_LDOUBLE_ = new PredType(H5T_NATIVE_LDOUBLE);
-#endif
-    NATIVE_B8_     = new PredType(H5T_NATIVE_B8);
-    NATIVE_B16_    = new PredType(H5T_NATIVE_B16);
-    NATIVE_B32_    = new PredType(H5T_NATIVE_B32);
-    NATIVE_B64_    = new PredType(H5T_NATIVE_B64);
-    NATIVE_OPAQUE_ = new PredType(H5T_NATIVE_OPAQUE);
-    NATIVE_HSIZE_  = new PredType(H5T_NATIVE_HSIZE);
-    NATIVE_HSSIZE_ = new PredType(H5T_NATIVE_HSSIZE);
-    NATIVE_HERR_   = new PredType(H5T_NATIVE_HERR);
-    NATIVE_HBOOL_  = new PredType(H5T_NATIVE_HBOOL);
+    NATIVE_B8_      = new PredType(H5T_NATIVE_B8);
+    NATIVE_B16_     = new PredType(H5T_NATIVE_B16);
+    NATIVE_B32_     = new PredType(H5T_NATIVE_B32);
+    NATIVE_B64_     = new PredType(H5T_NATIVE_B64);
+    NATIVE_OPAQUE_  = new PredType(H5T_NATIVE_OPAQUE);
+    NATIVE_HSIZE_   = new PredType(H5T_NATIVE_HSIZE);
+    NATIVE_HSSIZE_  = new PredType(H5T_NATIVE_HSSIZE);
+    NATIVE_HERR_    = new PredType(H5T_NATIVE_HERR);
+    NATIVE_HBOOL_   = new PredType(H5T_NATIVE_HBOOL);
 
     NATIVE_INT8_   = new PredType(H5T_NATIVE_INT8);
     NATIVE_UINT8_  = new PredType(H5T_NATIVE_UINT8);
diff --git a/fortran/src/H5_f.c b/fortran/src/H5_f.c
index d245cae..0277e5c 100644
--- a/fortran/src/H5_f.c
+++ b/fortran/src/H5_f.c
@@ -118,24 +118,20 @@ h5init_types_c(hid_t_f *types, hid_t_f *floatingtypes, hid_t_f *integertypes)
         if ((types[6] = (hid_t_f)H5Tcopy(H5T_NATIVE_DOUBLE)) < 0)
             return ret_value;
     } /* end if */
-#if H5_SIZEOF_LONG_DOUBLE != 0
     else if (sizeof(real_f) == sizeof(long double)) {
         if ((types[6] = (hid_t_f)H5Tcopy(H5T_NATIVE_LDOUBLE)) < 0)
             return ret_value;
     } /* end else */
-#endif
 
     /* Find appropriate size to store Fortran DOUBLE */
     if (sizeof(double_f) == sizeof(double)) {
         if ((types[7] = (hid_t_f)H5Tcopy(H5T_NATIVE_DOUBLE)) < 0)
             return ret_value;
     } /*end if */
-#if H5_SIZEOF_LONG_DOUBLE != 0
     else if (sizeof(double_f) == sizeof(long double)) {
         if ((types[7] = (hid_t_f)H5Tcopy(H5T_NATIVE_LDOUBLE)) < 0)
             return ret_value;
     } /*end else */
-#endif
 #ifdef H5_HAVE_FLOAT128
     else if (sizeof(double_f) == sizeof(__float128)) {
         if ((types[7] = H5Tcopy(H5T_NATIVE_FLOAT)) < 0)
@@ -169,12 +165,10 @@ h5init_types_c(hid_t_f *types, hid_t_f *floatingtypes, hid_t_f *integertypes)
         if ((types[11] = (hid_t_f)H5Tcopy(H5T_NATIVE_DOUBLE)) < 0)
             return ret_value;
     } /*end if */
-#if H5_SIZEOF_LONG_DOUBLE != 0
     else if (sizeof(real_C_FLOAT_f) == sizeof(long double)) {
         if ((types[11] = (hid_t_f)H5Tcopy(H5T_NATIVE_LDOUBLE)) < 0)
             return ret_value;
     } /*end else */
-#endif
     /*
      * FIND H5T_NATIVE_REAL_C_DOUBLE
      */
@@ -186,12 +180,10 @@ h5init_types_c(hid_t_f *types, hid_t_f *floatingtypes, hid_t_f *integertypes)
         if ((types[12] = (hid_t_f)H5Tcopy(H5T_NATIVE_DOUBLE)) < 0)
             return ret_value;
     } /*end if */
-#if H5_SIZEOF_LONG_DOUBLE != 0
     else if (sizeof(real_C_DOUBLE_f) == sizeof(long double)) {
         if ((types[12] = (hid_t_f)H5Tcopy(H5T_NATIVE_LDOUBLE)) < 0)
             return ret_value;
     } /*end else */
-#endif
     /*
      * FIND H5T_NATIVE_REAL_C_LONG_DOUBLE
      */
diff --git a/hl/fortran/src/H5LTfc.c b/hl/fortran/src/H5LTfc.c
index e87a9d3..4cb9265 100644
--- a/hl/fortran/src/H5LTfc.c
+++ b/hl/fortran/src/H5LTfc.c
@@ -319,11 +319,9 @@ h5ltset_attribute_c(hid_t_f *loc_id, size_t_f *namelen, _fcd dsetname, size_t_f
         else if ((size_t)*sizeof_val == sizeof(double))
             ret = H5LT_set_attribute_numerical(c_loc_id, c_name, c_attrname, c_size, H5T_NATIVE_DOUBLE,
                                                (const double *)buf);
-#if H5_SIZEOF_LONG_DOUBLE != 0
         else if ((size_t)*sizeof_val == sizeof(long double))
             ret = H5LT_set_attribute_numerical(c_loc_id, c_name, c_attrname, c_size, H5T_NATIVE_LDOUBLE,
                                                (const long double *)buf);
-#endif
         else
             goto done;
     }
@@ -413,10 +411,8 @@ h5ltget_attribute_c(hid_t_f *loc_id, size_t_f *namelen, _fcd dsetname, size_t_f
             ret = H5LTget_attribute(c_loc_id, c_name, c_attrname, H5T_NATIVE_FLOAT, buf);
         else if ((size_t)*sizeof_val == sizeof(double))
             ret = H5LTget_attribute(c_loc_id, c_name, c_attrname, H5T_NATIVE_DOUBLE, buf);
-#if H5_SIZEOF_LONG_DOUBLE != 0
         else if ((size_t)*sizeof_val == sizeof(long double))
             ret = H5LTget_attribute(c_loc_id, c_name, c_attrname, H5T_NATIVE_LDOUBLE, buf);
-#endif
         else
             goto done;
     }
diff --git a/hl/src/H5LT.c b/hl/src/H5LT.c
index 58a1b16..238bbf2 100644
--- a/hl/src/H5LT.c
+++ b/hl/src/H5LT.c
@@ -2529,11 +2529,9 @@ H5LT_dtype_to_text(hid_t dtype, char *dt_str, H5LT_lang_t lang, size_t *slen, hb
             }
             else if (H5Tequal(dtype, H5T_NATIVE_DOUBLE)) {
                 HDsnprintf(dt_str, *slen, "H5T_NATIVE_DOUBLE");
-#if H5_SIZEOF_LONG_DOUBLE != 0
             }
             else if (H5Tequal(dtype, H5T_NATIVE_LDOUBLE)) {
                 HDsnprintf(dt_str, *slen, "H5T_NATIVE_LDOUBLE");
-#endif
             }
             else {
                 HDsnprintf(dt_str, *slen, "undefined float");
diff --git a/java/src/jni/h5util.c b/java/src/jni/h5util.c
index 2550ad9..7313c28 100644
--- a/java/src/jni/h5util.c
+++ b/java/src/jni/h5util.c
@@ -237,7 +237,7 @@ h5str_convert(JNIEnv *env, char **in_str, hid_t container, hid_t tid, void *out_
                     HDmemcpy(cptr, &tmp_double, sizeof(double));
                     break;
                 }
-#if H5_SIZEOF_LONG_DOUBLE != 0 && H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
                 case sizeof(long double): {
                     long double tmp_ldouble = 0.0;
 
@@ -816,7 +816,7 @@ h5str_sprintf(JNIEnv *env, h5str_t *out_str, hid_t container, hid_t tid, void *i
 
                     break;
                 }
-#if H5_SIZEOF_LONG_DOUBLE != 0 && H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
                 case sizeof(long double): {
                     long double tmp_ldouble = 0.0;
 
diff --git a/src/H5HGprivate.h b/src/H5HGprivate.h
index d8e6b46..5deae88 100644
--- a/src/H5HGprivate.h
+++ b/src/H5HGprivate.h
@@ -50,7 +50,7 @@ typedef struct H5HG_heap_t H5HG_heap_t;
 
 /* Size of encoded global heap ID */
 /* (size of file address + 32-bit integer) */
-#define H5HG_HEAP_ID_SIZE(F) ((size_t)H5F_SIZEOF_ADDR(F) + H5_SIZEOF_UINT32_T)
+#define H5HG_HEAP_ID_SIZE(F) ((size_t)H5F_SIZEOF_ADDR(F) + sizeof(uint32_t))
 
 /* Main global heap routines */
 H5_DLL herr_t H5HG_insert(H5F_t *f, size_t size, const void *obj, H5HG_t *hobj /*out*/);
diff --git a/src/H5Rint.c b/src/H5Rint.c
index e1a5dcd..7ee4ecc 100644
--- a/src/H5Rint.c
+++ b/src/H5Rint.c
@@ -1150,7 +1150,7 @@ H5R__encode_obj_token(const H5O_token_t *obj_token, size_t token_size, unsigned
         /* Encode token */
         H5MM_memcpy(p, obj_token, token_size);
     }
-    *nalloc = token_size + H5_SIZEOF_UINT8_T;
+    *nalloc = token_size + sizeof(uint8_t);
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5R__encode_obj_token() */
@@ -1178,7 +1178,7 @@ H5R__decode_obj_token(const unsigned char *buf, size_t *nbytes, H5O_token_t *obj
     HDassert(token_size);
 
     /* Don't decode if buffer size isn't big enough */
-    if (*nbytes < H5_SIZEOF_UINT8_T)
+    if (*nbytes < sizeof(uint8_t))
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "Buffer size is too small")
 
     /* Get token size */
@@ -1192,7 +1192,7 @@ H5R__decode_obj_token(const unsigned char *buf, size_t *nbytes, H5O_token_t *obj
     /* Decode token */
     H5MM_memcpy(obj_token, p, *token_size);
 
-    *nbytes = (size_t)(*token_size + H5_SIZEOF_UINT8_T);
+    *nbytes = (size_t)(*token_size + sizeof(uint8_t));
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1225,7 +1225,7 @@ H5R__encode_region(H5S_t *space, unsigned char *buf, size_t *nalloc)
                     "Cannot determine amount of space needed for serializing selection")
 
     /* Don't encode if buffer size isn't big enough or buffer is empty */
-    if (buf && *nalloc >= ((size_t)buf_size + 2 * H5_SIZEOF_UINT32_T)) {
+    if (buf && *nalloc >= ((size_t)buf_size + 2 * sizeof(uint32_t))) {
         int rank;
         p = (uint8_t *)buf;
 
@@ -1241,7 +1241,7 @@ H5R__encode_region(H5S_t *space, unsigned char *buf, size_t *nalloc)
         if (H5S_SELECT_SERIALIZE(space, (unsigned char **)&p) < 0)
             HGOTO_ERROR(H5E_REFERENCE, H5E_CANTENCODE, FAIL, "can't serialize selection")
     } /* end if */
-    *nalloc = (size_t)buf_size + 2 * H5_SIZEOF_UINT32_T;
+    *nalloc = (size_t)buf_size + 2 * sizeof(uint32_t);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1272,16 +1272,16 @@ H5R__decode_region(const unsigned char *buf, size_t *nbytes, H5S_t **space_ptr)
     HDassert(space_ptr);
 
     /* Don't decode if buffer size isn't big enough */
-    if (*nbytes < (2 * H5_SIZEOF_UINT32_T))
+    if (*nbytes < (2 * sizeof(uint32_t)))
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "Buffer size is too small")
 
     /* Decode the selection size */
     UINT32DECODE(p, buf_size);
-    buf_size += H5_SIZEOF_UINT32_T;
+    buf_size += sizeof(uint32_t);
 
     /* Decode the extent rank */
     UINT32DECODE(p, rank);
-    buf_size += H5_SIZEOF_UINT32_T;
+    buf_size += sizeof(uint32_t);
 
     /* Don't decode if buffer size isn't big enough */
     if (*nbytes < buf_size)
diff --git a/src/H5Rpkg.h b/src/H5Rpkg.h
index ee5fb71..09144f9 100644
--- a/src/H5Rpkg.h
+++ b/src/H5Rpkg.h
@@ -43,7 +43,7 @@
 #define H5R_REF_ATTRNAME(x) ((x)->info.attr.name)
 
 /* Header size */
-#define H5R_ENCODE_HEADER_SIZE (2 * H5_SIZEOF_UINT8_T)
+#define H5R_ENCODE_HEADER_SIZE (2 * sizeof(uint8_t))
 
 /****************************/
 /* Package Private Typedefs */
diff --git a/src/H5T.c b/src/H5T.c
index 19a3d39..461e6b9 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -423,31 +423,29 @@ hid_t H5T_C_S1_g = FAIL;
 
 hid_t H5T_FORTRAN_S1_g = FAIL;
 
-hid_t H5T_NATIVE_SCHAR_g  = FAIL;
-hid_t H5T_NATIVE_UCHAR_g  = FAIL;
-hid_t H5T_NATIVE_SHORT_g  = FAIL;
-hid_t H5T_NATIVE_USHORT_g = FAIL;
-hid_t H5T_NATIVE_INT_g    = FAIL;
-hid_t H5T_NATIVE_UINT_g   = FAIL;
-hid_t H5T_NATIVE_LONG_g   = FAIL;
-hid_t H5T_NATIVE_ULONG_g  = FAIL;
-hid_t H5T_NATIVE_LLONG_g  = FAIL;
-hid_t H5T_NATIVE_ULLONG_g = FAIL;
-hid_t H5T_NATIVE_FLOAT_g  = FAIL;
-hid_t H5T_NATIVE_DOUBLE_g = FAIL;
-#if H5_SIZEOF_LONG_DOUBLE != 0
+hid_t H5T_NATIVE_SCHAR_g   = FAIL;
+hid_t H5T_NATIVE_UCHAR_g   = FAIL;
+hid_t H5T_NATIVE_SHORT_g   = FAIL;
+hid_t H5T_NATIVE_USHORT_g  = FAIL;
+hid_t H5T_NATIVE_INT_g     = FAIL;
+hid_t H5T_NATIVE_UINT_g    = FAIL;
+hid_t H5T_NATIVE_LONG_g    = FAIL;
+hid_t H5T_NATIVE_ULONG_g   = FAIL;
+hid_t H5T_NATIVE_LLONG_g   = FAIL;
+hid_t H5T_NATIVE_ULLONG_g  = FAIL;
+hid_t H5T_NATIVE_FLOAT_g   = FAIL;
+hid_t H5T_NATIVE_DOUBLE_g  = FAIL;
 hid_t H5T_NATIVE_LDOUBLE_g = FAIL;
-#endif
-hid_t H5T_NATIVE_B8_g     = FAIL;
-hid_t H5T_NATIVE_B16_g    = FAIL;
-hid_t H5T_NATIVE_B32_g    = FAIL;
-hid_t H5T_NATIVE_B64_g    = FAIL;
-hid_t H5T_NATIVE_OPAQUE_g = FAIL;
-hid_t H5T_NATIVE_HADDR_g  = FAIL;
-hid_t H5T_NATIVE_HSIZE_g  = FAIL;
-hid_t H5T_NATIVE_HSSIZE_g = FAIL;
-hid_t H5T_NATIVE_HERR_g   = FAIL;
-hid_t H5T_NATIVE_HBOOL_g  = FAIL;
+hid_t H5T_NATIVE_B8_g      = FAIL;
+hid_t H5T_NATIVE_B16_g     = FAIL;
+hid_t H5T_NATIVE_B32_g     = FAIL;
+hid_t H5T_NATIVE_B64_g     = FAIL;
+hid_t H5T_NATIVE_OPAQUE_g  = FAIL;
+hid_t H5T_NATIVE_HADDR_g   = FAIL;
+hid_t H5T_NATIVE_HSIZE_g   = FAIL;
+hid_t H5T_NATIVE_HSSIZE_g  = FAIL;
+hid_t H5T_NATIVE_HERR_g    = FAIL;
+hid_t H5T_NATIVE_HBOOL_g   = FAIL;
 
 hid_t H5T_NATIVE_INT8_g        = FAIL;
 hid_t H5T_NATIVE_UINT8_g       = FAIL;
@@ -483,21 +481,19 @@ hid_t H5T_NATIVE_UINT_FAST64_g  = FAIL;
  * datatype or C structures, which are different from the alignments for memory
  * address below this group of variables.
  */
-size_t H5T_NATIVE_SCHAR_COMP_ALIGN_g  = 0;
-size_t H5T_NATIVE_UCHAR_COMP_ALIGN_g  = 0;
-size_t H5T_NATIVE_SHORT_COMP_ALIGN_g  = 0;
-size_t H5T_NATIVE_USHORT_COMP_ALIGN_g = 0;
-size_t H5T_NATIVE_INT_COMP_ALIGN_g    = 0;
-size_t H5T_NATIVE_UINT_COMP_ALIGN_g   = 0;
-size_t H5T_NATIVE_LONG_COMP_ALIGN_g   = 0;
-size_t H5T_NATIVE_ULONG_COMP_ALIGN_g  = 0;
-size_t H5T_NATIVE_LLONG_COMP_ALIGN_g  = 0;
-size_t H5T_NATIVE_ULLONG_COMP_ALIGN_g = 0;
-size_t H5T_NATIVE_FLOAT_COMP_ALIGN_g  = 0;
-size_t H5T_NATIVE_DOUBLE_COMP_ALIGN_g = 0;
-#if H5_SIZEOF_LONG_DOUBLE != 0
+size_t H5T_NATIVE_SCHAR_COMP_ALIGN_g   = 0;
+size_t H5T_NATIVE_UCHAR_COMP_ALIGN_g   = 0;
+size_t H5T_NATIVE_SHORT_COMP_ALIGN_g   = 0;
+size_t H5T_NATIVE_USHORT_COMP_ALIGN_g  = 0;
+size_t H5T_NATIVE_INT_COMP_ALIGN_g     = 0;
+size_t H5T_NATIVE_UINT_COMP_ALIGN_g    = 0;
+size_t H5T_NATIVE_LONG_COMP_ALIGN_g    = 0;
+size_t H5T_NATIVE_ULONG_COMP_ALIGN_g   = 0;
+size_t H5T_NATIVE_LLONG_COMP_ALIGN_g   = 0;
+size_t H5T_NATIVE_ULLONG_COMP_ALIGN_g  = 0;
+size_t H5T_NATIVE_FLOAT_COMP_ALIGN_g   = 0;
+size_t H5T_NATIVE_DOUBLE_COMP_ALIGN_g  = 0;
 size_t H5T_NATIVE_LDOUBLE_COMP_ALIGN_g = 0;
-#endif
 
 size_t H5T_POINTER_COMP_ALIGN_g     = 0;
 size_t H5T_HVL_COMP_ALIGN_g         = 0;
@@ -509,21 +505,19 @@ size_t H5T_REF_COMP_ALIGN_g         = 0;
  * Alignment constraints for native types. These are initialized at run time
  * in H5Tinit.c
  */
-size_t H5T_NATIVE_SCHAR_ALIGN_g  = 0;
-size_t H5T_NATIVE_UCHAR_ALIGN_g  = 0;
-size_t H5T_NATIVE_SHORT_ALIGN_g  = 0;
-size_t H5T_NATIVE_USHORT_ALIGN_g = 0;
-size_t H5T_NATIVE_INT_ALIGN_g    = 0;
-size_t H5T_NATIVE_UINT_ALIGN_g   = 0;
-size_t H5T_NATIVE_LONG_ALIGN_g   = 0;
-size_t H5T_NATIVE_ULONG_ALIGN_g  = 0;
-size_t H5T_NATIVE_LLONG_ALIGN_g  = 0;
-size_t H5T_NATIVE_ULLONG_ALIGN_g = 0;
-size_t H5T_NATIVE_FLOAT_ALIGN_g  = 0;
-size_t H5T_NATIVE_DOUBLE_ALIGN_g = 0;
-#if H5_SIZEOF_LONG_DOUBLE != 0
+size_t H5T_NATIVE_SCHAR_ALIGN_g   = 0;
+size_t H5T_NATIVE_UCHAR_ALIGN_g   = 0;
+size_t H5T_NATIVE_SHORT_ALIGN_g   = 0;
+size_t H5T_NATIVE_USHORT_ALIGN_g  = 0;
+size_t H5T_NATIVE_INT_ALIGN_g     = 0;
+size_t H5T_NATIVE_UINT_ALIGN_g    = 0;
+size_t H5T_NATIVE_LONG_ALIGN_g    = 0;
+size_t H5T_NATIVE_ULONG_ALIGN_g   = 0;
+size_t H5T_NATIVE_LLONG_ALIGN_g   = 0;
+size_t H5T_NATIVE_ULLONG_ALIGN_g  = 0;
+size_t H5T_NATIVE_FLOAT_ALIGN_g   = 0;
+size_t H5T_NATIVE_DOUBLE_ALIGN_g  = 0;
 size_t H5T_NATIVE_LDOUBLE_ALIGN_g = 0;
-#endif
 
 /*
  * Alignment constraints for C9x types. These are initialized at run time in
@@ -760,42 +754,40 @@ DESCRIPTION
 herr_t
 H5T__init_package(void)
 {
-    H5T_t *native_schar  = NULL; /* Datatype structure for native signed char */
-    H5T_t *native_uchar  = NULL; /* Datatype structure for native unsigned char */
-    H5T_t *native_short  = NULL; /* Datatype structure for native short */
-    H5T_t *native_ushort = NULL; /* Datatype structure for native unsigned short */
-    H5T_t *native_int    = NULL; /* Datatype structure for native int */
-    H5T_t *native_uint   = NULL; /* Datatype structure for native unsigned int */
-    H5T_t *native_long   = NULL; /* Datatype structure for native long */
-    H5T_t *native_ulong  = NULL; /* Datatype structure for native unsigned long */
-    H5T_t *native_llong  = NULL; /* Datatype structure for native long long */
-    H5T_t *native_ullong = NULL; /* Datatype structure for native unsigned long long */
-    H5T_t *native_float  = NULL; /* Datatype structure for native float */
-    H5T_t *native_double = NULL; /* Datatype structure for native double */
-#if H5_SIZEOF_LONG_DOUBLE != 0
-    H5T_t *native_ldouble = NULL; /* Datatype structure for native long double */
-#endif
-    H5T_t * std_u8le  = NULL; /* Datatype structure for unsigned 8-bit little-endian integer */
-    H5T_t * std_u8be  = NULL; /* Datatype structure for unsigned 8-bit big-endian integer */
-    H5T_t * std_u16le = NULL; /* Datatype structure for unsigned 16-bit little-endian integer */
-    H5T_t * std_u16be = NULL; /* Datatype structure for unsigned 16-bit big-endian integer */
-    H5T_t * std_u32le = NULL; /* Datatype structure for unsigned 32-bit little-endian integer */
-    H5T_t * std_u32be = NULL; /* Datatype structure for unsigned 32-bit big-endian integer */
-    H5T_t * std_u64le = NULL; /* Datatype structure for unsigned 64-bit little-endian integer */
-    H5T_t * std_u64be = NULL; /* Datatype structure for unsigned 64-bit big-endian integer */
-    H5T_t * dt        = NULL;
-    H5T_t * fixedpt   = NULL; /* Datatype structure for native int */
-    H5T_t * floatpt   = NULL; /* Datatype structure for native float */
-    H5T_t * string    = NULL; /* Datatype structure for C string */
-    H5T_t * bitfield  = NULL; /* Datatype structure for bitfield */
-    H5T_t * compound  = NULL; /* Datatype structure for compound objects */
-    H5T_t * enum_type = NULL; /* Datatype structure for enum objects */
-    H5T_t * vlen      = NULL; /* Datatype structure for vlen objects */
-    H5T_t * array     = NULL; /* Datatype structure for array objects */
-    H5T_t * objref    = NULL; /* Datatype structure for deprecated reference objects */
-    H5T_t * regref    = NULL; /* Datatype structure for deprecated region references */
-    H5T_t * ref       = NULL; /* Datatype structure for opaque references */
-    hsize_t dim[1]    = {1};  /* Dimension info for array datatype */
+    H5T_t * native_schar   = NULL; /* Datatype structure for native signed char */
+    H5T_t * native_uchar   = NULL; /* Datatype structure for native unsigned char */
+    H5T_t * native_short   = NULL; /* Datatype structure for native short */
+    H5T_t * native_ushort  = NULL; /* Datatype structure for native unsigned short */
+    H5T_t * native_int     = NULL; /* Datatype structure for native int */
+    H5T_t * native_uint    = NULL; /* Datatype structure for native unsigned int */
+    H5T_t * native_long    = NULL; /* Datatype structure for native long */
+    H5T_t * native_ulong   = NULL; /* Datatype structure for native unsigned long */
+    H5T_t * native_llong   = NULL; /* Datatype structure for native long long */
+    H5T_t * native_ullong  = NULL; /* Datatype structure for native unsigned long long */
+    H5T_t * native_float   = NULL; /* Datatype structure for native float */
+    H5T_t * native_double  = NULL; /* Datatype structure for native double */
+    H5T_t * native_ldouble = NULL; /* Datatype structure for native long double */
+    H5T_t * std_u8le       = NULL; /* Datatype structure for unsigned 8-bit little-endian integer */
+    H5T_t * std_u8be       = NULL; /* Datatype structure for unsigned 8-bit big-endian integer */
+    H5T_t * std_u16le      = NULL; /* Datatype structure for unsigned 16-bit little-endian integer */
+    H5T_t * std_u16be      = NULL; /* Datatype structure for unsigned 16-bit big-endian integer */
+    H5T_t * std_u32le      = NULL; /* Datatype structure for unsigned 32-bit little-endian integer */
+    H5T_t * std_u32be      = NULL; /* Datatype structure for unsigned 32-bit big-endian integer */
+    H5T_t * std_u64le      = NULL; /* Datatype structure for unsigned 64-bit little-endian integer */
+    H5T_t * std_u64be      = NULL; /* Datatype structure for unsigned 64-bit big-endian integer */
+    H5T_t * dt             = NULL;
+    H5T_t * fixedpt        = NULL; /* Datatype structure for native int */
+    H5T_t * floatpt        = NULL; /* Datatype structure for native float */
+    H5T_t * string         = NULL; /* Datatype structure for C string */
+    H5T_t * bitfield       = NULL; /* Datatype structure for bitfield */
+    H5T_t * compound       = NULL; /* Datatype structure for compound objects */
+    H5T_t * enum_type      = NULL; /* Datatype structure for enum objects */
+    H5T_t * vlen           = NULL; /* Datatype structure for vlen objects */
+    H5T_t * array          = NULL; /* Datatype structure for array objects */
+    H5T_t * objref         = NULL; /* Datatype structure for deprecated reference objects */
+    H5T_t * regref         = NULL; /* Datatype structure for deprecated region references */
+    H5T_t * ref            = NULL; /* Datatype structure for opaque references */
+    hsize_t dim[1]         = {1};  /* Dimension info for array datatype */
     herr_t  status;
     hbool_t copied_dtype =
         TRUE; /* Flag to indicate whether datatype was copied or allocated (for error cleanup) */
@@ -843,10 +835,8 @@ H5T__init_package(void)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype object")
     if (NULL == (native_double = (H5T_t *)H5I_object(H5T_NATIVE_DOUBLE_g)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype object")
-#if H5_SIZEOF_LONG_DOUBLE != 0
     if (NULL == (native_ldouble = (H5T_t *)H5I_object(H5T_NATIVE_LDOUBLE_g)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype object")
-#endif
 
     /*------------------------------------------------------------
      * Derived native types
@@ -1116,7 +1106,6 @@ H5T__init_package(void)
         H5T__register_int(H5T_PERS_HARD, "flt_dbl", native_float, native_double, H5T__conv_float_double);
     status |=
         H5T__register_int(H5T_PERS_HARD, "dbl_flt", native_double, native_float, H5T__conv_double_float);
-#if H5_SIZEOF_LONG_DOUBLE != 0
     status |=
         H5T__register_int(H5T_PERS_HARD, "flt_ldbl", native_float, native_ldouble, H5T__conv_float_ldouble);
     status |=
@@ -1125,7 +1114,6 @@ H5T__init_package(void)
         H5T__register_int(H5T_PERS_HARD, "ldbl_flt", native_ldouble, native_float, H5T__conv_ldouble_float);
     status |=
         H5T__register_int(H5T_PERS_HARD, "ldbl_dbl", native_ldouble, native_double, H5T__conv_ldouble_double);
-#endif /* H5_SIZEOF_LONG_DOUBLE != 0 */
 
     /* from long long */
     status |=
@@ -1663,31 +1651,29 @@ H5T_top_term_package(void)
 
             H5T_FORTRAN_S1_g = FAIL;
 
-            H5T_NATIVE_SCHAR_g  = FAIL;
-            H5T_NATIVE_UCHAR_g  = FAIL;
-            H5T_NATIVE_SHORT_g  = FAIL;
-            H5T_NATIVE_USHORT_g = FAIL;
-            H5T_NATIVE_INT_g    = FAIL;
-            H5T_NATIVE_UINT_g   = FAIL;
-            H5T_NATIVE_LONG_g   = FAIL;
-            H5T_NATIVE_ULONG_g  = FAIL;
-            H5T_NATIVE_LLONG_g  = FAIL;
-            H5T_NATIVE_ULLONG_g = FAIL;
-            H5T_NATIVE_FLOAT_g  = FAIL;
-            H5T_NATIVE_DOUBLE_g = FAIL;
-#if H5_SIZEOF_LONG_DOUBLE != 0
+            H5T_NATIVE_SCHAR_g   = FAIL;
+            H5T_NATIVE_UCHAR_g   = FAIL;
+            H5T_NATIVE_SHORT_g   = FAIL;
+            H5T_NATIVE_USHORT_g  = FAIL;
+            H5T_NATIVE_INT_g     = FAIL;
+            H5T_NATIVE_UINT_g    = FAIL;
+            H5T_NATIVE_LONG_g    = FAIL;
+            H5T_NATIVE_ULONG_g   = FAIL;
+            H5T_NATIVE_LLONG_g   = FAIL;
+            H5T_NATIVE_ULLONG_g  = FAIL;
+            H5T_NATIVE_FLOAT_g   = FAIL;
+            H5T_NATIVE_DOUBLE_g  = FAIL;
             H5T_NATIVE_LDOUBLE_g = FAIL;
-#endif
-            H5T_NATIVE_B8_g     = FAIL;
-            H5T_NATIVE_B16_g    = FAIL;
-            H5T_NATIVE_B32_g    = FAIL;
-            H5T_NATIVE_B64_g    = FAIL;
-            H5T_NATIVE_OPAQUE_g = FAIL;
-            H5T_NATIVE_HADDR_g  = FAIL;
-            H5T_NATIVE_HSIZE_g  = FAIL;
-            H5T_NATIVE_HSSIZE_g = FAIL;
-            H5T_NATIVE_HERR_g   = FAIL;
-            H5T_NATIVE_HBOOL_g  = FAIL;
+            H5T_NATIVE_B8_g      = FAIL;
+            H5T_NATIVE_B16_g     = FAIL;
+            H5T_NATIVE_B32_g     = FAIL;
+            H5T_NATIVE_B64_g     = FAIL;
+            H5T_NATIVE_OPAQUE_g  = FAIL;
+            H5T_NATIVE_HADDR_g   = FAIL;
+            H5T_NATIVE_HSIZE_g   = FAIL;
+            H5T_NATIVE_HSSIZE_g  = FAIL;
+            H5T_NATIVE_HERR_g    = FAIL;
+            H5T_NATIVE_HBOOL_g   = FAIL;
 
             H5T_NATIVE_INT8_g        = FAIL;
             H5T_NATIVE_UINT8_g       = FAIL;
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 273bb23..c796c00 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -7009,14 +7009,12 @@ H5T__conv_float_double(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t ne
  *
  *-------------------------------------------------------------------------
  */
-#if H5_SIZEOF_LONG_DOUBLE != 0
 herr_t
 H5T__conv_float_ldouble(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts, size_t buf_stride,
                         size_t H5_ATTR_UNUSED bkg_stride, void *buf, void H5_ATTR_UNUSED *bkg)
 {
     H5T_CONV_fF(FLOAT, LDOUBLE, float, long double, -, -);
 }
-#endif /* H5_SIZEOF_LONG_DOUBLE != 0 */
 
 /*-------------------------------------------------------------------------
  * Function:    H5T__conv_double_float
@@ -7051,14 +7049,12 @@ H5T__conv_double_float(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t ne
  *
  *-------------------------------------------------------------------------
  */
-#if H5_SIZEOF_LONG_DOUBLE != 0
 herr_t
 H5T__conv_double_ldouble(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts, size_t buf_stride,
                          size_t H5_ATTR_UNUSED bkg_stride, void *buf, void H5_ATTR_UNUSED *bkg)
 {
     H5T_CONV_fF(DOUBLE, LDOUBLE, double, long double, -, -);
 }
-#endif /* H5_SIZEOF_LONG_DOUBLE != 0 */
 
 /*-------------------------------------------------------------------------
  * Function:    H5T__conv_ldouble_float
@@ -7073,14 +7069,12 @@ H5T__conv_double_ldouble(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t
  *
  *-------------------------------------------------------------------------
  */
-#if H5_SIZEOF_LONG_DOUBLE != 0
 herr_t
 H5T__conv_ldouble_float(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts, size_t buf_stride,
                         size_t H5_ATTR_UNUSED bkg_stride, void *buf, void H5_ATTR_UNUSED *bkg)
 {
     H5T_CONV_Ff(LDOUBLE, FLOAT, long double, float, -FLT_MAX, FLT_MAX);
 }
-#endif /* H5_SIZEOF_LONG_DOUBLE != 0 */
 
 /*-------------------------------------------------------------------------
  * Function:    H5T__conv_ldouble_double
@@ -7095,14 +7089,12 @@ H5T__conv_ldouble_float(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t n
  *
  *-------------------------------------------------------------------------
  */
-#if H5_SIZEOF_LONG_DOUBLE != 0
 herr_t
 H5T__conv_ldouble_double(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts, size_t buf_stride,
                          size_t H5_ATTR_UNUSED bkg_stride, void *buf, void H5_ATTR_UNUSED *bkg)
 {
     H5T_CONV_Ff(LDOUBLE, DOUBLE, long double, double, -DBL_MAX, DBL_MAX);
 }
-#endif /* H5_SIZEOF_LONG_DOUBLE != 0 */
 
 /*-------------------------------------------------------------------------
  * Function:    H5T__conv_schar_float
diff --git a/src/H5Tnative.c b/src/H5Tnative.c
index 2688b23..c9a2907 100644
--- a/src/H5Tnative.c
+++ b/src/H5Tnative.c
@@ -718,9 +718,7 @@ H5T__get_native_float(size_t size, H5T_direction_t direction, size_t *struct_ali
     enum match_type {          /* The different kinds of floating point types we can match */
                       H5T_NATIVE_FLOAT_MATCH_FLOAT,
                       H5T_NATIVE_FLOAT_MATCH_DOUBLE,
-#if H5_SIZEOF_LONG_DOUBLE != 0
                       H5T_NATIVE_FLOAT_MATCH_LDOUBLE,
-#endif
                       H5T_NATIVE_FLOAT_MATCH_UNKNOWN
     } match          = H5T_NATIVE_FLOAT_MATCH_UNKNOWN;
     H5T_t *ret_value = NULL; /* Return value */
@@ -738,24 +736,16 @@ H5T__get_native_float(size_t size, H5T_direction_t direction, size_t *struct_ali
             match       = H5T_NATIVE_FLOAT_MATCH_DOUBLE;
             native_size = sizeof(double);
         }
-#if H5_SIZEOF_LONG_DOUBLE != 0
         else if (size <= sizeof(long double)) {
             match       = H5T_NATIVE_FLOAT_MATCH_LDOUBLE;
             native_size = sizeof(long double);
         }
-#endif
         else { /* If not match, return the biggest datatype */
-#if H5_SIZEOF_LONG_DOUBLE != 0
             match       = H5T_NATIVE_FLOAT_MATCH_LDOUBLE;
             native_size = sizeof(long double);
-#else
-            match       = H5T_NATIVE_FLOAT_MATCH_DOUBLE;
-            native_size = sizeof(double);
-#endif
         }
     }
     else {
-#if H5_SIZEOF_LONG_DOUBLE != 0
         if (size > sizeof(double)) {
             match       = H5T_NATIVE_FLOAT_MATCH_LDOUBLE;
             native_size = sizeof(long double);
@@ -768,16 +758,6 @@ H5T__get_native_float(size_t size, H5T_direction_t direction, size_t *struct_ali
             match       = H5T_NATIVE_FLOAT_MATCH_FLOAT;
             native_size = sizeof(float);
         }
-#else
-        if (size > sizeof(float)) {
-            match = H5T_NATIVE_FLOAT_MATCH_DOUBLE;
-            native_size = sizeof(double);
-        }
-        else {
-            match = H5T_NATIVE_FLOAT_MATCH_FLOAT;
-            native_size = sizeof(float);
-        }
-#endif
     }
 
     /* Set the appropriate native floating point information */
@@ -792,12 +772,11 @@ H5T__get_native_float(size_t size, H5T_direction_t direction, size_t *struct_ali
             align = H5T_NATIVE_DOUBLE_COMP_ALIGN_g;
             break;
 
-#if H5_SIZEOF_LONG_DOUBLE != 0
         case H5T_NATIVE_FLOAT_MATCH_LDOUBLE:
             tid   = H5T_NATIVE_LDOUBLE;
             align = H5T_NATIVE_LDOUBLE_COMP_ALIGN_g;
             break;
-#endif
+
         case H5T_NATIVE_FLOAT_MATCH_UNKNOWN:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "Unknown native floating-point match")
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index 51ecaca..19593dd 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -401,9 +401,7 @@ H5_DLLVAR size_t H5T_NATIVE_LONG_COMP_ALIGN_g;
 H5_DLLVAR size_t H5T_NATIVE_LLONG_COMP_ALIGN_g;
 H5_DLLVAR size_t H5T_NATIVE_FLOAT_COMP_ALIGN_g;
 H5_DLLVAR size_t H5T_NATIVE_DOUBLE_COMP_ALIGN_g;
-#if H5_SIZEOF_LONG_DOUBLE != 0
 H5_DLLVAR size_t H5T_NATIVE_LDOUBLE_COMP_ALIGN_g;
-#endif
 
 H5_DLLVAR size_t H5T_POINTER_COMP_ALIGN_g;
 H5_DLLVAR size_t H5T_HVL_COMP_ALIGN_g;
@@ -429,9 +427,7 @@ H5_DLLVAR size_t H5T_NATIVE_LLONG_ALIGN_g;
 H5_DLLVAR size_t H5T_NATIVE_ULLONG_ALIGN_g;
 H5_DLLVAR size_t H5T_NATIVE_FLOAT_ALIGN_g;
 H5_DLLVAR size_t H5T_NATIVE_DOUBLE_ALIGN_g;
-#if H5_SIZEOF_LONG_DOUBLE != 0
 H5_DLLVAR size_t H5T_NATIVE_LDOUBLE_ALIGN_g;
-#endif
 
 /* C9x alignment constraints */
 H5_DLLVAR size_t H5T_NATIVE_INT8_ALIGN_g;
@@ -468,10 +464,8 @@ H5_DLLVAR float  H5T_NATIVE_FLOAT_POS_INF_g;
 H5_DLLVAR float  H5T_NATIVE_FLOAT_NEG_INF_g;
 H5_DLLVAR double H5T_NATIVE_DOUBLE_POS_INF_g;
 H5_DLLVAR double H5T_NATIVE_DOUBLE_NEG_INF_g;
-#if H5_SIZEOF_LONG_DOUBLE != 0
 H5_DLLVAR double H5T_NATIVE_LDOUBLE_POS_INF_g;
 H5_DLLVAR double H5T_NATIVE_LDOUBLE_NEG_INF_g;
-#endif
 
 /* Declare extern the free lists for H5T_t's and H5T_shared_t's */
 H5FL_EXTERN(H5T_t);
diff --git a/src/H5Tpublic.h b/src/H5Tpublic.h
index bb5b0ef..911efdf 100644
--- a/src/H5Tpublic.h
+++ b/src/H5Tpublic.h
@@ -803,13 +803,11 @@ H5_DLLVAR hid_t H5T_VAX_F64_g;
  * C-style \Code{double}
  */
 #define H5T_NATIVE_DOUBLE (H5OPEN H5T_NATIVE_DOUBLE_g)
-#if H5_SIZEOF_LONG_DOUBLE != 0
 /**
  * \ingroup PDTNAT
  * C-style \Code{long double}
  */
 #define H5T_NATIVE_LDOUBLE (H5OPEN H5T_NATIVE_LDOUBLE_g)
-#endif
 /**
  * \ingroup PDTNAT
  * HDF5 8-bit bitfield based on native types
@@ -872,9 +870,7 @@ H5_DLLVAR hid_t H5T_NATIVE_LLONG_g;
 H5_DLLVAR hid_t H5T_NATIVE_ULLONG_g;
 H5_DLLVAR hid_t H5T_NATIVE_FLOAT_g;
 H5_DLLVAR hid_t H5T_NATIVE_DOUBLE_g;
-#if H5_SIZEOF_LONG_DOUBLE != 0
 H5_DLLVAR hid_t H5T_NATIVE_LDOUBLE_g;
-#endif
 H5_DLLVAR hid_t H5T_NATIVE_B8_g;
 H5_DLLVAR hid_t H5T_NATIVE_B16_g;
 H5_DLLVAR hid_t H5T_NATIVE_B32_g;
diff --git a/src/H5Tref.c b/src/H5Tref.c
index cac8cf6..511c531 100644
--- a/src/H5Tref.c
+++ b/src/H5Tref.c
@@ -309,8 +309,8 @@ H5T__ref_set_loc(H5T_t *dt, H5VL_object_t *file, H5T_loc_t loc)
                     HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "can't get encode size")
 
                 /* Size on disk, memory size is different */
-                dt->shared->size = MAX(H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE + cont_info.blob_id_size,
-                                       ref_encode_size);
+                dt->shared->size =
+                    MAX(sizeof(uint32_t) + H5R_ENCODE_HEADER_SIZE + cont_info.blob_id_size, ref_encode_size);
                 dt->shared->u.atomic.prec = 8 * dt->shared->size;
 
                 /* Set up the function pointers to access the information on
@@ -778,7 +778,7 @@ H5T__ref_disk_isnull(const H5VL_object_t *src_file, const void *src_buf, hbool_t
         H5VL_blob_specific_args_t vol_cb_args; /* Arguments to VOL callback */
 
         /* Skip the size / header */
-        p = (const uint8_t *)src_buf + H5R_ENCODE_HEADER_SIZE + H5_SIZEOF_UINT32_T;
+        p = (const uint8_t *)src_buf + H5R_ENCODE_HEADER_SIZE + sizeof(uint32_t);
 
         /* Set up VOL callback arguments */
         vol_cb_args.op_type             = H5VL_BLOB_ISNULL;
@@ -819,7 +819,7 @@ H5T__ref_disk_setnull(H5VL_object_t *dst_file, void *dst_buf, void *bg_buf)
     /* TODO Should get rid of bg stuff */
     if (p_bg) {
         /* Skip the size / header */
-        p_bg += (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE);
+        p_bg += (sizeof(uint32_t) + H5R_ENCODE_HEADER_SIZE);
 
         /* Set up VOL callback arguments */
         vol_cb_args.op_type = H5VL_BLOB_DELETE;
@@ -929,8 +929,8 @@ H5T__ref_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t H5_ATTR_
     blob_size -= H5R_ENCODE_HEADER_SIZE;
 
     /* Skip the size */
-    p += H5_SIZEOF_UINT32_T;
-    HDassert(src_size > (H5R_ENCODE_HEADER_SIZE + H5_SIZEOF_UINT32_T));
+    p += sizeof(uint32_t);
+    HDassert(src_size > (H5R_ENCODE_HEADER_SIZE + sizeof(uint32_t)));
 
     /* Retrieve blob */
     if (H5VL_blob_get(src_file, p, q, blob_size, NULL) < 0)
@@ -974,9 +974,9 @@ H5T__ref_disk_write(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
         size_t                    p_buf_size_left = dst_size;
 
         /* Skip the size / header */
-        p_bg += (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE);
-        HDassert(p_buf_size_left > (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE));
-        p_buf_size_left -= (H5_SIZEOF_UINT32_T + H5R_ENCODE_HEADER_SIZE);
+        p_bg += (sizeof(uint32_t) + H5R_ENCODE_HEADER_SIZE);
+        HDassert(p_buf_size_left > (sizeof(uint32_t) + H5R_ENCODE_HEADER_SIZE));
+        p_buf_size_left -= (sizeof(uint32_t) + H5R_ENCODE_HEADER_SIZE);
 
         /* Set up VOL callback arguments */
         vol_cb_args.op_type = H5VL_BLOB_DELETE;
@@ -991,12 +991,12 @@ H5T__ref_disk_write(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
     p += H5R_ENCODE_HEADER_SIZE;
     q += H5R_ENCODE_HEADER_SIZE;
     src_size -= H5R_ENCODE_HEADER_SIZE;
-    buf_size_left -= H5_SIZEOF_UINT32_T;
+    buf_size_left -= sizeof(uint32_t);
 
     /* Set the size */
     UINT32ENCODE(q, src_size);
-    HDassert(buf_size_left > H5_SIZEOF_UINT32_T);
-    buf_size_left -= H5_SIZEOF_UINT32_T;
+    HDassert(buf_size_left > sizeof(uint32_t));
+    buf_size_left -= sizeof(uint32_t);
 
     /* Store blob */
     if (H5VL_blob_put(dst_file, p, src_size, q, NULL) < 0)
diff --git a/src/H5Ztrans.c b/src/H5Ztrans.c
index ab7e9be..ea532cf 100644
--- a/src/H5Ztrans.c
+++ b/src/H5Ztrans.c
@@ -150,7 +150,6 @@ static void       H5Z__xform_reduce_tree(H5Z_node *tree);
             HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Unexpected type conversion operation")                \
     }
 
-#if H5_SIZEOF_LONG_DOUBLE != 0
 #if CHAR_MIN >= 0
 #define H5Z_XFORM_TYPE_OP(RESL, RESR, TYPE, OP, SIZE)                                                        \
     {                                                                                                        \
@@ -212,65 +211,6 @@ static void       H5Z__xform_reduce_tree(H5Z_node *tree);
             H5Z_XFORM_DO_OP1((RESL), (RESR), long double, OP, (SIZE))                                        \
     }
 #endif /* CHAR_MIN >= 0 */
-#else
-#if CHAR_MIN >= 0
-#define H5Z_XFORM_TYPE_OP(RESL, RESR, TYPE, OP, SIZE)                                                        \
-    {                                                                                                        \
-        if ((TYPE) == H5T_NATIVE_CHAR)                                                                       \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), char, OP, (SIZE))                                               \
-        else if ((TYPE) == H5T_NATIVE_SCHAR)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), signed char, OP, (SIZE))                                        \
-        else if ((TYPE) == H5T_NATIVE_SHORT)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), short, OP, (SIZE))                                              \
-        else if ((TYPE) == H5T_NATIVE_USHORT)                                                                \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned short, OP, (SIZE))                                     \
-        else if ((TYPE) == H5T_NATIVE_INT)                                                                   \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), int, OP, (SIZE))                                                \
-        else if ((TYPE) == H5T_NATIVE_UINT)                                                                  \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned int, OP, (SIZE))                                       \
-        else if ((TYPE) == H5T_NATIVE_LONG)                                                                  \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), long, OP, (SIZE))                                               \
-        else if ((TYPE) == H5T_NATIVE_ULONG)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned long, OP, (SIZE))                                      \
-        else if ((TYPE) == H5T_NATIVE_LLONG)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), long long, OP, (SIZE))                                          \
-        else if ((TYPE) == H5T_NATIVE_ULLONG)                                                                \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned long long, OP, (SIZE))                                 \
-        else if ((TYPE) == H5T_NATIVE_FLOAT)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), float, OP, (SIZE))                                              \
-        else if ((TYPE) == H5T_NATIVE_DOUBLE)                                                                \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), double, OP, (SIZE))                                             \
-    }
-#else /* CHAR_MIN >= 0 */
-#define H5Z_XFORM_TYPE_OP(RESL, RESR, TYPE, OP, SIZE)                                                        \
-    {                                                                                                        \
-        if ((TYPE) == H5T_NATIVE_CHAR)                                                                       \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), char, OP, (SIZE))                                               \
-        else if ((TYPE) == H5T_NATIVE_UCHAR)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned char, OP, (SIZE))                                      \
-        else if ((TYPE) == H5T_NATIVE_SHORT)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), short, OP, (SIZE))                                              \
-        else if ((TYPE) == H5T_NATIVE_USHORT)                                                                \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned short, OP, (SIZE))                                     \
-        else if ((TYPE) == H5T_NATIVE_INT)                                                                   \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), int, OP, (SIZE))                                                \
-        else if ((TYPE) == H5T_NATIVE_UINT)                                                                  \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned int, OP, (SIZE))                                       \
-        else if ((TYPE) == H5T_NATIVE_LONG)                                                                  \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), long, OP, (SIZE))                                               \
-        else if ((TYPE) == H5T_NATIVE_ULONG)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned long, OP, (SIZE))                                      \
-        else if ((TYPE) == H5T_NATIVE_LLONG)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), long long, OP, (SIZE))                                          \
-        else if ((TYPE) == H5T_NATIVE_ULLONG)                                                                \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), unsigned long long, OP, (SIZE))                                 \
-        else if ((TYPE) == H5T_NATIVE_FLOAT)                                                                 \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), float, OP, (SIZE))                                              \
-        else if ((TYPE) == H5T_NATIVE_DOUBLE)                                                                \
-            H5Z_XFORM_DO_OP1((RESL), (RESR), double, OP, (SIZE))                                             \
-    }
-#endif /* CHAR_MIN >= 0 */
-#endif /*H5_SIZEOF_LONG_DOUBLE */
 
 #define H5Z_XFORM_DO_OP3(OP)                                                                                 \
     {                                                                                                        \
@@ -1056,10 +996,8 @@ H5Z_xform_eval(H5Z_data_xform_t *data_xform_prop, void *array, size_t array_size
             H5Z_XFORM_DO_OP5(float, array_size)
         else if (array_type == H5T_NATIVE_DOUBLE)
             H5Z_XFORM_DO_OP5(double, array_size)
-#if H5_SIZEOF_LONG_DOUBLE != 0
         else if (array_type == H5T_NATIVE_LDOUBLE)
             H5Z_XFORM_DO_OP5(long double, array_size)
-#endif
 
     } /* end if */
     /* Otherwise, do the full data transform */
@@ -1267,11 +1205,9 @@ H5Z__xform_find_type(const H5T_t *type)
     /* Check for DOUBLE type */
     else if ((tmp = (H5T_t *)H5I_object(H5T_NATIVE_DOUBLE)) && 0 == H5T_cmp(type, tmp, FALSE))
         HGOTO_DONE(H5T_NATIVE_DOUBLE)
-#if H5_SIZEOF_LONG_DOUBLE != 0
     /* Check for LONGDOUBLE type */
     else if ((tmp = (H5T_t *)H5I_object(H5T_NATIVE_LDOUBLE)) && 0 == H5T_cmp(type, tmp, FALSE))
         HGOTO_DONE(H5T_NATIVE_LDOUBLE)
-#endif
     else
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "could not find matching type")
 
diff --git a/src/H5detect.c b/src/H5detect.c
index e8cded7..022cb55 100644
--- a/src/H5detect.c
+++ b/src/H5detect.c
@@ -1412,7 +1412,7 @@ detect_C99_floats(void)
      */
     DETECT_F(double, LDOUBLE, d_g[nd_g]);
     nd_g++;
-#elif H5_SIZEOF_LONG_DOUBLE != 0
+#else
     DETECT_F(long double, LDOUBLE, d_g[nd_g]);
     nd_g++;
 #endif
diff --git a/src/H5trace.c b/src/H5trace.c
index 0797f65..baf6a10 100644
--- a/src/H5trace.c
+++ b/src/H5trace.c
@@ -1622,10 +1622,8 @@ H5_trace_args(H5RS_str_t *rs, const char *type, va_list ap)
                                     H5RS_acat(rs, "H5T_NATIVE_FLOAT");
                                 else if (obj == H5T_NATIVE_DOUBLE_g)
                                     H5RS_acat(rs, "H5T_NATIVE_DOUBLE");
-#if H5_SIZEOF_LONG_DOUBLE != 0
                                 else if (obj == H5T_NATIVE_LDOUBLE_g)
                                     H5RS_acat(rs, "H5T_NATIVE_LDOUBLE");
-#endif
                                 else if (obj == H5T_IEEE_F32BE_g)
                                     H5RS_acat(rs, "H5T_IEEE_F32BE");
                                 else if (obj == H5T_IEEE_F32LE_g)
diff --git a/test/dt_arith.c b/test/dt_arith.c
index 4cdb020..7e96d29 100644
--- a/test/dt_arith.c
+++ b/test/dt_arith.c
@@ -68,9 +68,7 @@ typedef enum dtype_t {
     INT_ULLONG,
     FLT_FLOAT,
     FLT_DOUBLE,
-#if H5_SIZEOF_LONG_DOUBLE != 0
     FLT_LDOUBLE,
-#endif
     OTHER
 } dtype_t;
 
@@ -457,10 +455,8 @@ reset_hdf5(void)
     SET_ALIGNMENT(ULLONG, H5_SIZEOF_LONG_LONG);
     SET_ALIGNMENT(FLOAT, H5_SIZEOF_FLOAT);
     SET_ALIGNMENT(DOUBLE, H5_SIZEOF_DOUBLE);
-#if H5_SIZEOF_LONG_DOUBLE != 0
     SET_ALIGNMENT(LDOUBLE, H5_SIZEOF_LONG_DOUBLE);
 #endif
-#endif
 }
 
 /*-------------------------------------------------------------------------
@@ -2704,7 +2700,7 @@ my_isnan(dtype_t type, void *val)
         double x = 0.0;
         HDmemcpy(&x, val, sizeof(double));
         retval = (x != x);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     }
     else if (FLT_LDOUBLE == type) {
         long double x = 0.0L;
@@ -2732,7 +2728,7 @@ my_isnan(dtype_t type, void *val)
 
             HDmemcpy(&x, val, sizeof(double));
             HDsnprintf(s, sizeof(s), "%g", x);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
         }
         else if (FLT_LDOUBLE == type) {
             long double x = 0.0L;
@@ -2898,7 +2894,7 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
     else if (H5Tequal(src, H5T_NATIVE_DOUBLE)) {
         src_type_name = "double";
         src_type      = FLT_DOUBLE;
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     }
     else if (H5Tequal(src, H5T_NATIVE_LDOUBLE)) {
         src_type_name = "long double";
@@ -2917,7 +2913,7 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
     else if (H5Tequal(dst, H5T_NATIVE_DOUBLE)) {
         dst_type_name = "double";
         dst_type      = FLT_DOUBLE;
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     }
     else if (H5Tequal(dst, H5T_NATIVE_LDOUBLE)) {
         dst_type_name = "long double";
@@ -3000,7 +2996,7 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
             else if (src_type == FLT_DOUBLE) {
                 INIT_FP_NORM(double, DBL_MAX, DBL_MIN, DBL_MAX_10_EXP, DBL_MIN_10_EXP, src_size, dst_size,
                              buf, saved, nelmts);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
             }
             else if (src_type == FLT_LDOUBLE) {
                 INIT_FP_NORM(long double, LDBL_MAX, LDBL_MIN, LDBL_MAX_10_EXP, LDBL_MIN_10_EXP, src_size,
@@ -3019,7 +3015,7 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
             else if (src_type == FLT_DOUBLE) {
                 INIT_FP_DENORM(double, DBL_MANT_DIG, src_size, src_nbits, sendian, dst_size, buf, saved,
                                nelmts);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
             }
             else if (src_type == FLT_LDOUBLE) {
                 INIT_FP_DENORM(long double, LDBL_MANT_DIG, src_size, src_nbits, sendian, dst_size, buf, saved,
@@ -3037,7 +3033,7 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
             }
             else if (src_type == FLT_DOUBLE) {
                 INIT_FP_SPECIAL(src_size, src_nbits, sendian, DBL_MANT_DIG, dst_size, buf, saved, nelmts);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
             }
             else if (src_type == FLT_LDOUBLE) {
                 INIT_FP_SPECIAL(src_size, src_nbits, sendian, LDBL_MANT_DIG, dst_size, buf, saved, nelmts);
@@ -3133,7 +3129,6 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
          * last few unused bytes may have garbage in them.  Clean them out with
          * 0s before compare the values.
          */
-#if H5_SIZEOF_LONG_DOUBLE != 0
         if (sendian == H5T_ORDER_LE && dst_type == FLT_LDOUBLE) {
             size_t q;
 
@@ -3142,7 +3137,6 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
                 hw[q]                 = 0x00;
             }
         }
-#endif
 
         /* Are the two results the same? */
         for (k = (dst_size - (dst_nbits / 8)); k < dst_size; k++)
@@ -3163,7 +3157,7 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
         else if (FLT_DOUBLE == dst_type && my_isnan(dst_type, buf + j * sizeof(double)) &&
                  my_isnan(dst_type, hw)) {
             continue;
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
         }
         else if (FLT_LDOUBLE == dst_type && my_isnan(dst_type, buf + j * sizeof(long double)) &&
                  my_isnan(dst_type, hw)) {
@@ -3217,7 +3211,7 @@ test_conv_flt_1(const char *name, int run_test, hid_t src, hid_t dst)
                     continue; /* all overflowed, no error */
                 check_mant[0] = HDfrexp(x, check_expo + 0);
                 check_mant[1] = HDfrexp(hw_d, check_expo + 1);
-#if H5_SIZEOF_LONG_DOUBLE != 0 && (H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE)
+#if (H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE)
             }
             else {
                 long double x = 0.0L;
@@ -3506,7 +3500,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
     else if (H5Tequal(src, H5T_NATIVE_DOUBLE)) {
         src_type_name = "double";
         src_type      = FLT_DOUBLE;
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     }
     else if (H5Tequal(src, H5T_NATIVE_LDOUBLE)) {
         src_type_name = "long double";
@@ -3566,7 +3560,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
     else if (H5Tequal(dst, H5T_NATIVE_DOUBLE)) {
         dst_type_name = "double";
         dst_type      = FLT_DOUBLE;
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     }
     else if (H5Tequal(dst, H5T_NATIVE_LDOUBLE)) {
         dst_type_name = "long double";
@@ -3590,11 +3584,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
     if ((INT_SCHAR == src_type || INT_UCHAR == src_type || INT_SHORT == src_type || INT_USHORT == src_type ||
          INT_INT == src_type || INT_UINT == src_type || INT_LONG == src_type || INT_ULONG == src_type ||
          INT_LLONG == src_type || INT_ULLONG == src_type) &&
-        (FLT_FLOAT != dst_type && FLT_DOUBLE != dst_type
-#if H5_SIZEOF_LONG_DOUBLE != 0
-         && FLT_LDOUBLE != dst_type
-#endif
-         )) {
+        (FLT_FLOAT != dst_type && FLT_DOUBLE != dst_type && FLT_LDOUBLE != dst_type)) {
         HDsnprintf(str, sizeof(str), "Testing %s %s -> %s conversions", name, src_type_name, dst_type_name);
         HDprintf("%-70s", str);
         H5_FAILED();
@@ -3602,11 +3592,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
         goto error;
     }
 
-    if ((FLT_FLOAT == src_type || FLT_DOUBLE == src_type
-#if H5_SIZEOF_LONG_DOUBLE != 0
-         || FLT_LDOUBLE == src_type
-#endif
-         ) &&
+    if ((FLT_FLOAT == src_type || FLT_DOUBLE == src_type || FLT_LDOUBLE == src_type) &&
         (INT_SCHAR != dst_type && INT_UCHAR != dst_type && INT_SHORT != dst_type && INT_USHORT != dst_type &&
          INT_INT != dst_type && INT_UINT != dst_type && INT_LONG != dst_type && INT_ULONG != dst_type &&
          INT_LLONG != dst_type && INT_ULLONG != dst_type)) {
@@ -3738,7 +3724,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
         else {
             INIT_FP_SPECIAL(src_size, src_nbits, sendian, DBL_MANT_DIG, dst_size, buf, saved, nelmts);
         }
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     }
     else if (src_type == FLT_LDOUBLE) {
         if (run_test == TEST_NORMAL) {
@@ -3763,11 +3749,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
 
     /* Check the results from the library against hardware */
     for (j = 0; j < nelmts; j++) {
-        if (FLT_FLOAT == src_type || FLT_DOUBLE == src_type
-#if H5_SIZEOF_LONG_DOUBLE != 0
-            || FLT_LDOUBLE == src_type
-#endif
-        )
+        if (FLT_FLOAT == src_type || FLT_DOUBLE == src_type || FLT_LDOUBLE == src_type)
             if (my_isnan(src_type, saved + j * src_size))
                 continue;
 
@@ -3874,7 +3856,6 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDassert(0 && "Unknown type");
                     break;
             }
-#if H5_SIZEOF_LONG_DOUBLE != 0
         }
         else if (FLT_LDOUBLE == dst_type) {
             hw = (unsigned char *)&hw_ldouble;
@@ -3927,7 +3908,6 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDassert(0 && "Unknown type");
                     break;
             }
-#endif
         }
         else if (INT_SCHAR == dst_type) {
             hw = (unsigned char *)&hw_schar;
@@ -3940,12 +3920,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_schar = (signed char)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_schar = (signed char)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -3973,12 +3951,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_uchar = (unsigned char)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_uchar = (unsigned char)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4006,12 +3982,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_short = (short)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_short = (short)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4039,12 +4013,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_ushort = (unsigned short)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_ushort = (unsigned short)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4072,12 +4044,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_int = (int)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_int = (int)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4105,12 +4075,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_uint = (unsigned int)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_uint = (unsigned int)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4138,12 +4106,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_long = (long)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_long = (long)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4171,12 +4137,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_ulong = (unsigned long)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_ulong = (unsigned long)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4204,12 +4168,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_llong = (long long)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_llong = (long long)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4237,12 +4199,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                     HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                     hw_ullong = (unsigned long long)(*((double *)aligned));
                     break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 case FLT_LDOUBLE:
                     HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                     hw_ullong = (unsigned long long)(*((long double *)aligned));
                     break;
-#endif
                 case INT_SCHAR:
                 case INT_UCHAR:
                 case INT_SHORT:
@@ -4269,14 +4229,12 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
          * bytes may have garbage in them.  Clean them out with 0s before compare
          * the values.
          */
-#if H5_SIZEOF_LONG_DOUBLE != 0
         if (dendian == H5T_ORDER_LE && dst_type == FLT_LDOUBLE) {
             size_t q;
 
             for (q = dst_nbits / 8; q < dst_size; q++)
                 buf[j * dst_size + q] = 0x00;
         }
-#endif
 
         /* Are the two results the same? */
         for (k = (dst_size - (dst_nbits / 8)); k < dst_size; k++)
@@ -4315,11 +4273,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
          * Try to follow the except_func callback function to check if the
          * desired value was set.
          */
-        if ((FLT_FLOAT == src_type || FLT_DOUBLE == src_type
-#if H5_SIZEOF_LONG_DOUBLE != 0
-             || FLT_LDOUBLE == src_type
-#endif
-             ) &&
+        if ((FLT_FLOAT == src_type || FLT_DOUBLE == src_type || FLT_LDOUBLE == src_type) &&
             (INT_SCHAR == dst_type || INT_SHORT == dst_type || INT_INT == dst_type || INT_LONG == dst_type ||
              INT_LLONG == dst_type)) {
             if (0 == H5T__bit_get_d(src_bits, src_nbits - 1, (size_t)1) &&
@@ -4359,11 +4313,7 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
             }
         }
 
-        if ((FLT_FLOAT == src_type || FLT_DOUBLE == src_type
-#if H5_SIZEOF_LONG_DOUBLE != 0
-             || FLT_LDOUBLE == src_type
-#endif
-             ) &&
+        if ((FLT_FLOAT == src_type || FLT_DOUBLE == src_type || FLT_LDOUBLE == src_type) &&
             (INT_UCHAR == dst_type || INT_USHORT == dst_type || INT_UINT == dst_type ||
              INT_ULONG == dst_type || INT_ULLONG == dst_type)) {
             if (H5T__bit_get_d(src_bits, src_nbits - 1, (size_t)1)) {
@@ -4462,12 +4412,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                 HDmemcpy(aligned, saved + j * sizeof(double), sizeof(double));
                 HDprintf(" %29f\n", *((double *)aligned));
                 break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
             case FLT_LDOUBLE:
                 HDmemcpy(aligned, saved + j * sizeof(long double), sizeof(long double));
                 HDprintf(" %29Lf\n", *((long double *)aligned));
                 break;
-#endif
             case OTHER:
             default:
                 HDassert(0 && "Unknown type");
@@ -4527,12 +4475,10 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
                 HDmemcpy(aligned, buf + j * sizeof(double), sizeof(double));
                 HDprintf(" %29f\n", *((double *)aligned));
                 break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
             case FLT_LDOUBLE:
                 HDmemcpy(aligned, buf + j * sizeof(long double), sizeof(long double));
                 HDprintf(" %29Lf\n", *((long double *)aligned));
                 break;
-#endif
             case OTHER:
             default:
                 HDassert(0 && "Unknown type");
@@ -4580,11 +4526,9 @@ test_conv_int_fp(const char *name, int run_test, hid_t src, hid_t dst)
             case FLT_DOUBLE:
                 HDprintf(" %29f\n", *((double *)((void *)hw)));
                 break;
-#if H5_SIZEOF_LONG_DOUBLE != 0
             case FLT_LDOUBLE:
                 HDprintf(" %29Lf\n", *((long double *)((void *)hw)));
                 break;
-#endif
             case OTHER:
             default:
                 HDassert(0 && "Unknown type");
@@ -4923,16 +4867,14 @@ run_fp_tests(const char *name)
     if (!HDstrcmp(name, "noop")) {
         nerrors += test_conv_flt_1("noop", TEST_NOOP, H5T_NATIVE_FLOAT, H5T_NATIVE_FLOAT);
         nerrors += test_conv_flt_1("noop", TEST_NOOP, H5T_NATIVE_DOUBLE, H5T_NATIVE_DOUBLE);
-#if H5_SIZEOF_LONG_DOUBLE != 0
         nerrors += test_conv_flt_1("noop", TEST_NOOP, H5T_NATIVE_LDOUBLE, H5T_NATIVE_LDOUBLE);
-#endif
         goto done;
     }
 
     /*Test normalized values.  TEST_NORMAL indicates normalized values.*/
     nerrors += test_conv_flt_1(name, TEST_NORMAL, H5T_NATIVE_FLOAT, H5T_NATIVE_DOUBLE);
     nerrors += test_conv_flt_1(name, TEST_NORMAL, H5T_NATIVE_DOUBLE, H5T_NATIVE_FLOAT);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     nerrors += test_conv_flt_1(name, TEST_NORMAL, H5T_NATIVE_FLOAT, H5T_NATIVE_LDOUBLE);
     nerrors += test_conv_flt_1(name, TEST_NORMAL, H5T_NATIVE_DOUBLE, H5T_NATIVE_LDOUBLE);
     nerrors += test_conv_flt_1(name, TEST_NORMAL, H5T_NATIVE_LDOUBLE, H5T_NATIVE_FLOAT);
@@ -4942,7 +4884,7 @@ run_fp_tests(const char *name)
     /*Test denormalized values.  TEST_DENORM indicates denormalized values.*/
     nerrors += test_conv_flt_1(name, TEST_DENORM, H5T_NATIVE_FLOAT, H5T_NATIVE_DOUBLE);
     nerrors += test_conv_flt_1(name, TEST_DENORM, H5T_NATIVE_DOUBLE, H5T_NATIVE_FLOAT);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     nerrors += test_conv_flt_1(name, TEST_DENORM, H5T_NATIVE_FLOAT, H5T_NATIVE_LDOUBLE);
     nerrors += test_conv_flt_1(name, TEST_DENORM, H5T_NATIVE_DOUBLE, H5T_NATIVE_LDOUBLE);
 #ifndef H5_DISABLE_SOME_LDOUBLE_CONV
@@ -4955,11 +4897,7 @@ run_fp_tests(const char *name)
                    "float");
         HDprintf("%-70s", str);
         SKIPPED();
-#if H5_SIZEOF_LONG_DOUBLE != 0
         HDputs("    Test skipped due to the conversion problem on IBM ppc64le cpu.");
-#else
-        HDputs("    Test skipped due to disabled long double.");
-#endif
     }
 #endif
 
@@ -4969,7 +4907,7 @@ run_fp_tests(const char *name)
     /*Test special values, +/-0, +/-infinity, +/-QNaN, +/-SNaN.*/
     nerrors += test_conv_flt_1(name, TEST_SPECIAL, H5T_NATIVE_FLOAT, H5T_NATIVE_DOUBLE);
     nerrors += test_conv_flt_1(name, TEST_SPECIAL, H5T_NATIVE_DOUBLE, H5T_NATIVE_FLOAT);
-#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_DOUBLE != H5_SIZEOF_DOUBLE
     nerrors += test_conv_flt_1(name, TEST_SPECIAL, H5T_NATIVE_FLOAT, H5T_NATIVE_LDOUBLE);
     nerrors += test_conv_flt_1(name, TEST_SPECIAL, H5T_NATIVE_DOUBLE, H5T_NATIVE_LDOUBLE);
 #ifndef H5_DISABLE_SOME_LDOUBLE_CONV
@@ -4983,11 +4921,7 @@ run_fp_tests(const char *name)
                    "float or double");
         HDprintf("%-70s", str);
         SKIPPED();
-#if H5_SIZEOF_LONG_DOUBLE != 0
         HDputs("    Test skipped due to the conversion problem on IBM ppc64le cpu.");
-#else
-        HDputs("    Test skipped due to disabled long double.");
-#endif
     }
 #endif
 #endif
@@ -5068,11 +5002,7 @@ run_int_fp_conv(const char *name)
                    "long double");
         HDprintf("%-70s", str);
         SKIPPED();
-#if H5_SIZEOF_LONG_DOUBLE != 0
         HDputs("    Test skipped due to the special algorithm of hardware conversion.");
-#else
-        HDputs("    Test skipped due to disabled long double.");
-#endif
     }
 #endif
 #endif /* H5_SIZEOF_LONG!=H5_SIZEOF_INT */
@@ -5193,14 +5123,10 @@ run_fp_int_conv(const char *name)
                        "signed and unsigned char, short, int, long");
             HDprintf("%-70s", str);
             SKIPPED();
-#if H5_SIZEOF_LONG_DOUBLE != 0
             HDputs("    Test skipped due to the conversion problem on IBM ppc64le cpu.");
-#else
-            HDputs("    Test skipped due to disabled long double.");
-#endif
 #endif
         }
-#if H5_SIZEOF_LONG != H5_SIZEOF_INT && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG != H5_SIZEOF_INT
 #ifndef H5_LDOUBLE_TO_LONG_SPECIAL
         if (test_values != TEST_SPECIAL && test_values != TEST_NORMAL) {
             nerrors += test_conv_int_fp(name, test_values, H5T_NATIVE_LDOUBLE, H5T_NATIVE_LONG);
@@ -5220,35 +5146,27 @@ run_fp_int_conv(const char *name)
                        "(unsigned) long");
             HDprintf("%-70s", str);
             SKIPPED();
-#if H5_SIZEOF_LONG_DOUBLE != 0
             HDputs("    Test skipped due to the special algorithm of hardware conversion.");
-#else
-            HDputs("    Test skipped due to disabled long double.");
-#endif
         }
 #endif
-#endif /*H5_SIZEOF_LONG!=H5_SIZEOF_INT && H5_SIZEOF_LONG_DOUBLE!=0 */
+#endif /*H5_SIZEOF_LONG!=H5_SIZEOF_INT */
 
-#if H5_SIZEOF_LONG_LONG != H5_SIZEOF_LONG && H5_SIZEOF_LONG_DOUBLE != 0
+#if H5_SIZEOF_LONG_LONG != H5_SIZEOF_LONG
 #ifdef H5_LDOUBLE_TO_LLONG_ACCURATE
         nerrors += test_conv_int_fp(name, test_values, H5T_NATIVE_LDOUBLE, H5T_NATIVE_LLONG);
-#else /*H5_LDOUBLE_TO_LLONG_ACCURATE*/
+#else  /*H5_LDOUBLE_TO_LLONG_ACCURATE*/
         {
             char str[256]; /*string        */
 
             HDsnprintf(str, sizeof(str), "Testing %s %s -> %s conversions", name, "long double", "long long");
             HDprintf("%-70s", str);
             SKIPPED();
-#if H5_SIZEOF_LONG_DOUBLE != 0
             HDputs("    Test skipped due to hardware conversion error.");
-#else
-            HDputs("    Test skipped due to disabled long double.");
-#endif
         }
 #endif /*H5_LDOUBLE_TO_LLONG_ACCURATE*/
 #if defined(H5_LDOUBLE_TO_LLONG_ACCURATE)
         nerrors += test_conv_int_fp(name, test_values, H5T_NATIVE_LDOUBLE, H5T_NATIVE_ULLONG);
-#else /*H5_LDOUBLE_TO_LLONG_ACCURATE*/
+#else  /*H5_LDOUBLE_TO_LLONG_ACCURATE*/
         {
             char str[256]; /*string        */
 
@@ -5256,11 +5174,7 @@ run_fp_int_conv(const char *name)
                        "unsigned long long");
             HDprintf("%-70s", str);
             SKIPPED();
-#if H5_SIZEOF_LONG_DOUBLE != 0
             HDputs("    Test skipped due to hardware conversion error.");
-#else
-            HDputs("    Test skipped due to disabled long double.");
-#endif
         }
 #endif /*H5_LDOUBLE_TO_LLONG_ACCURATE*/
 #endif
diff --git a/test/dtransform.c b/test/dtransform.c
index b721a59..5d1c04f 100644
--- a/test/dtransform.c
+++ b/test/dtransform.c
@@ -359,9 +359,7 @@ main(void)
     TEST_TYPE_CONTIG(dxpl_id_utrans_inv, unsigned long long, H5T_NATIVE_ULLONG, "ullong", transformData, 0);
     TEST_TYPE_CONTIG(dxpl_id_c_to_f, float, H5T_NATIVE_FLOAT, "float", windchillFfloat, 1);
     TEST_TYPE_CONTIG(dxpl_id_c_to_f, double, H5T_NATIVE_DOUBLE, "double", windchillFfloat, 1);
-#if H5_SIZEOF_LONG_DOUBLE != 0
     TEST_TYPE_CONTIG(dxpl_id_c_to_f, long double, H5T_NATIVE_LDOUBLE, "ldouble", windchillFfloat, 1);
-#endif
 
     TEST_TYPE_CHUNK(dxpl_id_utrans_inv, char, H5T_NATIVE_CHAR, "char", transformData, 0);
     TEST_TYPE_CHUNK(dxpl_id_utrans_inv, unsigned char, H5T_NATIVE_UCHAR, "uchar", transformData, 0);
@@ -376,9 +374,7 @@ main(void)
     TEST_TYPE_CHUNK(dxpl_id_utrans_inv, unsigned long long, H5T_NATIVE_ULLONG, "ullong", transformData, 0);
     TEST_TYPE_CHUNK(dxpl_id_c_to_f, float, H5T_NATIVE_FLOAT, "float", windchillFfloat, 1);
     TEST_TYPE_CHUNK(dxpl_id_c_to_f, double, H5T_NATIVE_DOUBLE, "double", windchillFfloat, 1);
-#if H5_SIZEOF_LONG_DOUBLE != 0
     TEST_TYPE_CHUNK(dxpl_id_c_to_f, long double, H5T_NATIVE_LDOUBLE, "ldouble", windchillFfloat, 1);
-#endif
 
     if (test_copy(dxpl_id_c_to_f_copy, dxpl_id_polynomial_copy) < 0)
         TEST_ERROR;
diff --git a/test/dtypes.c b/test/dtypes.c
index 1c1a6ec..e9a2461 100644
--- a/test/dtypes.c
+++ b/test/dtypes.c
@@ -160,10 +160,8 @@ reset_hdf5(void)
     SET_ALIGNMENT(ULLONG, H5_SIZEOF_LONG_LONG);
     SET_ALIGNMENT(FLOAT, H5_SIZEOF_FLOAT);
     SET_ALIGNMENT(DOUBLE, H5_SIZEOF_DOUBLE);
-#if H5_SIZEOF_LONG_DOUBLE != 0
     SET_ALIGNMENT(LDOUBLE, H5_SIZEOF_LONG_DOUBLE);
 #endif
-#endif
 }
 
 /*-------------------------------------------------------------------------
diff --git a/test/tconfig.c b/test/tconfig.c
index 101de9a..8bd625f 100644
--- a/test/tconfig.c
+++ b/test/tconfig.c
@@ -114,30 +114,14 @@ test_config_ctypes(void)
     vrfy_cint_type(long, unsigned long, H5_SIZEOF_LONG);
     vrfy_ctype(float, H5_SIZEOF_FLOAT);
     vrfy_ctype(double, H5_SIZEOF_DOUBLE);
-#if H5_SIZEOF_LONG_DOUBLE > 0
     vrfy_ctype(long double, H5_SIZEOF_LONG_DOUBLE);
-#endif
 
     /* standard C99 basic types */
-#if H5_SIZEOF_LONG_LONG > 0
     vrfy_cint_type(long long, unsigned long long, H5_SIZEOF_LONG_LONG);
-#endif
-
-#if H5_SIZEOF_INT8_T > 0
     vrfy_cint_type(int8_t, uint8_t, H5_SIZEOF_INT8_T);
-#endif
-
-#if H5_SIZEOF_INT16_T > 0
     vrfy_cint_type(int16_t, uint16_t, H5_SIZEOF_INT16_T);
-#endif
-
-#if H5_SIZEOF_INT32_T > 0
     vrfy_cint_type(int32_t, uint32_t, H5_SIZEOF_INT32_T);
-#endif
-
-#if H5_SIZEOF_INT64_T > 0
     vrfy_cint_type(int64_t, uint64_t, H5_SIZEOF_INT64_T);
-#endif
 
     /* Some vendors have different sizes for the signed and unsigned */
     /* fast8_t.  Need to check them individually. */
diff --git a/tools/lib/h5diff_array.c b/tools/lib/h5diff_array.c
index e16a045..362a2f3 100644
--- a/tools/lib/h5diff_array.c
+++ b/tools/lib/h5diff_array.c
@@ -24,12 +24,8 @@
  *-------------------------------------------------------------------------
  */
 
-#define F_FORMAT "%-15g %-15g %-15g\n"
-
-#if H5_SIZEOF_LONG_DOUBLE != 0
-#define LD_FORMAT "%-15Lg %-15Lg %-15Lg\n"
-#endif
-
+#define F_FORMAT    "%-15g %-15g %-15g\n"
+#define LD_FORMAT   "%-15Lg %-15Lg %-15Lg\n"
 #define I_FORMAT    "%-15d %-15d %-15d\n"
 #define S_FORMAT    "%-16s %-17s\n"
 #define UI_FORMAT   "%-15u %-15u %-15u\n"
@@ -39,12 +35,8 @@
 #define ULLI_FORMAT "%-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "u %-15" H5_PRINTF_LL_WIDTH "u\n"
 
 /* with -p option */
-#define F_FORMAT_P "%-15.10g %-15.10g %-15.10g %-14.10g\n"
-
-#if H5_SIZEOF_LONG_DOUBLE != 0
-#define LD_FORMAT_P "%-15.10Lg %-15.10Lg %-15.10Lg %-14.10Lg\n"
-#endif
-
+#define F_FORMAT_P   "%-15.10g %-15.10g %-15.10g %-14.10g\n"
+#define LD_FORMAT_P  "%-15.10Lg %-15.10Lg %-15.10Lg %-14.10Lg\n"
 #define I_FORMAT_P   "%-15d %-15d %-15d %-14f\n"
 #define UI_FORMAT_P  "%-15u %-15u %-15u %-14f\n"
 #define LI_FORMAT_P  "%-15ld %-15ld %-15ld %-14f\n"
@@ -56,12 +48,8 @@
 #define SPACES "          "
 
 /* not comparable */
-#define F_FORMAT_P_NOTCOMP "%-15.10g %-15.10g %-15.10g not comparable\n"
-
-#if H5_SIZEOF_LONG_DOUBLE != 0
-#define LD_FORMAT_P_NOTCOMP "%-15.10Lg %-15.10Lg %-15.10Lg not comparable\n"
-#endif
-
+#define F_FORMAT_P_NOTCOMP   "%-15.10g %-15.10g %-15.10g not comparable\n"
+#define LD_FORMAT_P_NOTCOMP  "%-15.10Lg %-15.10Lg %-15.10Lg not comparable\n"
 #define I_FORMAT_P_NOTCOMP   "%-15d %-15d %-15d not comparable\n"
 #define UI_FORMAT_P_NOTCOMP  "%-15u %-15u %-15u not comparable\n"
 #define LI_FORMAT_P_NOTCOMP  "%-15ld %-15ld %-15ld not comparable\n"
@@ -145,9 +133,7 @@ static hsize_t character_compare_opt(unsigned char *mem1, unsigned char *mem2, h
                                      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(diff_opt_t *opts, hsize_t elemtno, size_t u);
@@ -162,10 +148,8 @@ static hsize_t diff_float_element(unsigned char *mem1, unsigned char *mem2, hsiz
                                   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_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx,
                                     diff_opt_t *opts);
-#endif
 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,
@@ -191,12 +175,7 @@ static hsize_t diff_ullong_element(unsigned char *mem1, unsigned char *mem2, hsi
  *-------------------------------------------------------------------------
  */
 
-#if H5_SIZEOF_LONG_DOUBLE != 0
 typedef enum dtype_t { FLT_FLOAT, FLT_DOUBLE, FLT_LDOUBLE } dtype_t;
-#else
-
-typedef enum dtype_t { FLT_FLOAT, FLT_DOUBLE } dtype_t;
-#endif
 
 /*-------------------------------------------------------------------------
  * XCAO, 11/10/2010
@@ -278,7 +257,6 @@ diff_array(void *_mem1, void *_mem2, diff_opt_t *opts, hid_t container1_id, hid_
                         return nfound;
                 } /* nelmts */
             }
-#if H5_SIZEOF_LONG_DOUBLE != 0
             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);
@@ -289,7 +267,6 @@ diff_array(void *_mem1, void *_mem2, diff_opt_t *opts, hid_t container1_id, hid_
                         return nfound;
                 } /* nelmts */
             }
-#endif
             break;
 
         case H5T_INTEGER:
@@ -2034,7 +2011,6 @@ diff_double_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx,
  * Return:   number of differences found
  *-------------------------------------------------------------------------
  */
-#if H5_SIZEOF_LONG_DOUBLE != 0
 
 static hsize_t
 diff_ldouble_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx, diff_opt_t *opts)
@@ -2200,7 +2176,6 @@ diff_ldouble_element(unsigned char *mem1, unsigned char *mem2, hsize_t elem_idx,
 
     return nfound;
 }
-#endif /* H5_SIZEOF_LONG_DOUBLE */
 
 /*-------------------------------------------------------------------------
  * Function: diff_schar_element
@@ -3203,7 +3178,6 @@ 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)
 {
@@ -3244,8 +3218,6 @@ equal_ldouble(long double value, long double expected, diff_opt_t *opts)
     return FALSE;
 }
 
-#endif /* #if H5_SIZEOF_LONG_DOUBLE !=0 */
-
 /*-------------------------------------------------------------------------
  * Function:    equal_float
  *
diff --git a/tools/lib/h5diff_util.c b/tools/lib/h5diff_util.c
index e487a12..c40de9d 100644
--- a/tools/lib/h5diff_util.c
+++ b/tools/lib/h5diff_util.c
@@ -133,10 +133,8 @@ print_type(hid_t type)
                 parallel_print("H5T_NATIVE_FLOAT");
             else if (H5Tequal(type, H5T_NATIVE_DOUBLE))
                 parallel_print("H5T_NATIVE_DOUBLE");
-#if H5_SIZEOF_LONG_DOUBLE != 0
             else if (H5Tequal(type, H5T_NATIVE_LDOUBLE))
                 parallel_print("H5T_NATIVE_LDOUBLE");
-#endif
             else
                 parallel_print("undefined float");
             break;
diff --git a/tools/lib/h5tools_str.c b/tools/lib/h5tools_str.c
index abc0058..3cd12bb 100644
--- a/tools/lib/h5tools_str.c
+++ b/tools/lib/h5tools_str.c
@@ -705,7 +705,6 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
 
                     HDmemcpy(&tempdouble, vp, sizeof(double));
                     h5tools_str_append(str, OPT(info->fmt_double, "%g"), tempdouble);
-#if H5_SIZEOF_LONG_DOUBLE != 0
                 }
                 else if (sizeof(long double) == nsize) {
                     /* if (H5Tequal(type, H5T_NATIVE_LDOUBLE)) */
@@ -713,7 +712,6 @@ h5tools_str_sprint(h5tools_str_t *str, const h5tool_format_t *info, hid_t contai
 
                     HDmemcpy(&templdouble, vp, sizeof(long double));
                     h5tools_str_append(str, "%Lg", templdouble);
-#endif
                 }
                 else {
                     size_t i;
diff --git a/tools/src/h5import/h5import.c b/tools/src/h5import/h5import.c
index 6517e43..7272dff 100644
--- a/tools/src/h5import/h5import.c
+++ b/tools/src/h5import/h5import.c
@@ -467,14 +467,12 @@ readIntegerData(FILE *strm, struct Input *in)
     H5DT_INT16  temp16;
     H5DT_INT32 *in32;
     H5DT_INT32  temp32;
-#ifdef H5_SIZEOF_LONG_LONG
     H5DT_INT64 *in64;
     H5DT_INT64  temp64;
     char        buffer[256];
-#endif
-    hsize_t len = 1;
-    hsize_t i;
-    int     j;
+    hsize_t     len = 1;
+    hsize_t     i;
+    int         j;
 
     const char *err1 = "Unable to get integer value from file.\n";
     const char *err2 = "Unrecognized input class type.\n";
@@ -589,7 +587,6 @@ readIntegerData(FILE *strm, struct Input *in)
             }
             break;
 
-#ifdef H5_SIZEOF_LONG_LONG
         case 64:
             in64 = (H5DT_INT64 *)in->data;
             switch (in->inputClass) {
@@ -626,7 +623,6 @@ readIntegerData(FILE *strm, struct Input *in)
                     return (-1);
             }
             break;
-#endif /* ifdef H5_SIZEOF_LONG_LONG */
 
         default:
             (void)HDfprintf(stderr, "%s", err3);
@@ -643,17 +639,15 @@ readUIntegerData(FILE *strm, struct Input *in)
     H5DT_UINT16  temp16;
     H5DT_UINT32 *in32;
     H5DT_UINT32  temp32;
-#ifdef H5_SIZEOF_LONG_LONG
     H5DT_UINT64 *in64;
     H5DT_UINT64  temp64;
     char         buffer[256];
-#endif
-    hsize_t     len = 1;
-    hsize_t     i;
-    int         j;
-    const char *err1 = "Unable to get unsigned integer value from file.\n";
-    const char *err2 = "Unrecognized input class type.\n";
-    const char *err3 = "Invalid input size.\n";
+    hsize_t      len = 1;
+    hsize_t      i;
+    int          j;
+    const char * err1 = "Unable to get unsigned integer value from file.\n";
+    const char * err2 = "Unrecognized input class type.\n";
+    const char * err3 = "Invalid input size.\n";
 
     for (j = 0; j < in->rank; j++)
         len *= in->sizeOfDimension[j];
@@ -760,7 +754,6 @@ readUIntegerData(FILE *strm, struct Input *in)
             }
             break;
 
-#ifdef H5_SIZEOF_LONG_LONG
         case 64:
             in64 = (H5DT_UINT64 *)in->data;
             switch (in->inputClass) {
@@ -797,7 +790,6 @@ readUIntegerData(FILE *strm, struct Input *in)
                     return (-1);
             }
             break;
-#endif /* ifdef H5_SIZEOF_LONG_LONG */
 
         default:
             (void)HDfprintf(stderr, "%s", err3);
@@ -2457,9 +2449,6 @@ validateConfigurationParameters(struct Input *in)
     const char *err4a = "OUTPUT-ARCHITECTURE cannot be STD if OUTPUT-CLASS is floating point (FP).\n";
     const char *err4b = "OUTPUT-ARCHITECTURE cannot be IEEE if OUTPUT-CLASS is integer (IN).\n";
     const char *err5  = "For OUTPUT-CLASS FP, valid values for OUTPUT-SIZE are (32, 64) .\n";
-#ifndef H5_SIZEOF_LONG_LONG
-    const char *err6 = "No support for reading 64-bit integer (INPUT-CLASS: IN, TEXTIN, UIN, TEXTUIN files\n";
-#endif
 
     /* for class STR other parameters are ignored */
     if (in->inputClass == 5) /* STR */
@@ -2505,13 +2494,6 @@ validateConfigurationParameters(struct Input *in)
             return (-1);
         }
 
-#ifndef H5_SIZEOF_LONG_LONG
-    if (in->inputSize == 64 &&
-        (in->inputClass == 0 || in->inputClass == 4 || in->inputClass == 6 || in->inputClass == 7)) {
-        (void)HDfprintf(stderr, "%s", err6);
-        return -1;
-    }
-#endif
     return (0);
 }
 
@@ -3250,7 +3232,6 @@ getInputClassType(struct Input *in, char *buffer)
 
         kindex = 3;
     }
-#if H5_SIZEOF_LONG_DOUBLE != 0
     else if (!HDstrcmp(buffer, "H5T_NATIVE_LDOUBLE")) {
         in->inputSize                      = H5_SIZEOF_LONG_DOUBLE;
         in->configOptionVector[INPUT_SIZE] = 1;
@@ -3263,7 +3244,6 @@ getInputClassType(struct Input *in, char *buffer)
 
         kindex = 3;
     }
-#endif
     else if (!HDstrcmp(buffer, "H5T_TIME: not yet implemented")) {
         kindex = -1;
     }
diff --git a/tools/test/h5diff/h5diffgentest.c b/tools/test/h5diff/h5diffgentest.c
index 8b23e27..5a0f7bf 100644
--- a/tools/test/h5diff/h5diffgentest.c
+++ b/tools/test/h5diff/h5diffgentest.c
@@ -442,7 +442,6 @@ test_basic(const char *fname1, const char *fname2, const char *fname3)
         write_dset(gid1, 2, dims2, "d2", H5T_NATIVE_DOUBLE, data14);
     }
 
-#if H5_SIZEOF_LONG_DOUBLE != 0
     {
 
         /*-------------------------------------------------------------------------
@@ -454,7 +453,6 @@ test_basic(const char *fname1, const char *fname2, const char *fname3)
 
         write_dset(gid1, 2, dims2, "ld", H5T_NATIVE_LDOUBLE, data15);
     }
-#endif
 
     /*-------------------------------------------------------------------------
      * NaNs in H5T_NATIVE_FLOAT
diff --git a/tools/test/h5import/h5importtest.c b/tools/test/h5import/h5importtest.c
index e49125b..7dbf762 100644
--- a/tools/test/h5import/h5importtest.c
+++ b/tools/test/h5import/h5importtest.c
@@ -46,11 +46,9 @@ main(void)
     int rowo4i = 11, colo4i = 21, plno4i = 51;
     int rowi4i = 1, coli4i = 2, plni4i = 5;
 
-#ifdef H5_SIZEOF_LONG_LONG
     long long row4i64[3], col4i64[4], pln4i64[5];
     long long rowo4i64 = (long long)11, colo4i64 = (long long)21, plno4i64 = (long long)51;
     long long rowi4i64 = (long long)1, coli4i64 = (long long)2, plni4i64 = (long long)5;
-#endif
 
     short b16i3[5][3][4];
     short row4i16[3], col4i16[4], pln4i16[5];
@@ -101,11 +99,9 @@ main(void)
     col4i[0] = colo4i;
     pln4i[0] = plno4i;
 
-#ifdef H5_SIZEOF_LONG_LONG
     row4i64[0] = rowo4i64;
     col4i64[0] = colo4i64;
     pln4i64[0] = plno4i64;
-#endif
 
     row4i16[0] = rowo4i16;
     col4i16[0] = colo4i16;
@@ -116,33 +112,27 @@ main(void)
     pln4i8[0] = plno4i8;
 
     for (i = 1; i < nrow; i++) {
-        row4[i]  = row4[i - 1] + rowi4;
-        row8[i]  = row8[i - 1] + rowi8;
-        row4i[i] = row4i[i - 1] + rowi4i;
-#ifdef H5_SIZEOF_LONG_LONG
+        row4[i]    = row4[i - 1] + rowi4;
+        row8[i]    = row8[i - 1] + rowi8;
+        row4i[i]   = row4i[i - 1] + rowi4i;
         row4i64[i] = row4i64[i - 1] + rowi4i64;
-#endif
         row4i16[i] = (short)(row4i16[i - 1] + rowi4i16);
         row4i8[i]  = (char)(row4i8[i - 1] + rowi4i8);
     }
 
     for (j = 1; j < ncol; j++) {
-        col4[j]  = col4[j - 1] + coli4;
-        col8[j]  = col8[j - 1] + coli8;
-        col4i[j] = col4i[j - 1] + coli4i;
-#ifdef H5_SIZEOF_LONG_LONG
+        col4[j]    = col4[j - 1] + coli4;
+        col8[j]    = col8[j - 1] + coli8;
+        col4i[j]   = col4i[j - 1] + coli4i;
         col4i64[j] = col4i64[j - 1] + coli4i64;
-#endif
         col4i16[j] = (short)(col4i16[j - 1] + coli4i16);
         col4i8[j]  = (char)(col4i8[j - 1] + coli4i8);
     }
     for (k = 1; k < npln; k++) {
-        pln4[k]  = pln4[k - 1] + plni4;
-        pln8[k]  = pln8[k - 1] + plni8;
-        pln4i[k] = pln4i[k - 1] + plni4i;
-#ifdef H5_SIZEOF_LONG_LONG
+        pln4[k]    = pln4[k - 1] + plni4;
+        pln8[k]    = pln8[k - 1] + plni8;
+        pln4i[k]   = pln4i[k - 1] + plni4i;
         pln4i64[k] = pln4i64[k - 1] + plni4i64;
-#endif
         pln4i16[k] = (short)(pln4i16[k - 1] + plni4i16);
         pln4i8[k]  = (char)(pln4i8[k - 1] + plni4i8);
     }