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-rw-r--r--configure.in57
1 files changed, 56 insertions, 1 deletions
diff --git a/configure.in b/configure.in
index f668717..3dfacbc 100644
--- a/configure.in
+++ b/configure.in
@@ -2685,7 +2685,7 @@ AC_CACHE_VAL([hdf5_cv_fp_to_ullong_right_maximum],
unsigned long long l2 = (unsigned long long)d1;
unsigned long long l3 = (unsigned long long)d2;
unsigned long long l4;
- unsigned long long l5 = 0x7fffffffffffffffLLU;
+ unsigned long long l5 = 0x7fffffffffffffffULL;
int ret = 0;
if(l1 <= l5 || l2 <= l5 || l3 <= l5)
@@ -2728,6 +2728,61 @@ else
fi
dnl ----------------------------------------------------------------------
+dnl Set the flag to indicate that the machine can convert from
+dnl 'unsigned long long' to 'long double' without precision loss.
+dnl (This flag should be set for all machines, except for FreeBSD(sleipnir)
+dnl where the last 2 bytes of mantissa are lost when compiler tries to do
+dnl the conversion.)
+dnl
+AC_MSG_CHECKING([if converting unsigned long long to long double with precision work])
+AC_CACHE_VAL([hdf5_cv_ullong_to_ldouble_precision_works],
+ [AC_TRY_RUN([
+ int main(void)
+ {
+ unsigned long long l = 0xa601e80bda85fcefULL;
+ long double ld;
+ unsigned char *c1, *c2;
+ int endian, size;
+ int tst_value = 1;
+ int i;
+ int ret = 0;
+
+ /* Determine this system's endianess */
+ c1 = (unsigned char*)calloc(1, sizeof(int));
+ memcpy(c1, &tst_value, sizeof(int));
+ if(c1[0]==1)
+ endian = 0; /* little endian */
+ else
+ endian = 1; /* big endian */
+
+ memset(&ld, 0, 12);
+ ld = (long double)l;
+
+ size = sizeof(long double);
+ c2 = (unsigned char*)malloc(size);
+ memcpy(c2, &ld, size);
+
+ /* Test if the last 2 bytes of mantissa are lost. Mainly for FreeBSD on Intel
+ * architecture(sleipnir) where it happens. */
+ if(endian==0 && c2[0]==0 && c2[1]==0) /*little endian*/
+ ret = 1;
+
+ free(c1);
+ free(c2);
+done:
+ exit(ret);
+ }
+ ], [hdf5_cv_ullong_to_ldouble_precision_works=yes], [hdf5_cv_ullong_to_ldouble_precision_works=no],)])
+
+if test ${hdf5_cv_ullong_to_ldouble_precision_works} = "yes"; then
+ AC_DEFINE([ULLONG_TO_LDOUBLE_PRECISION_WORKS], [1],
+ [Define if your system can convert unsigned long long to long double with correct precision.])
+ 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