[svn-r9809] Purpose: bug fix

Description:  For HP-UX11.00, compiler's casting from 'long double' to most of
integers.  A macro was hard set in config/hpux11.00 before.

Solution:  Let configure detect this case and set the macro.

Platforms tested:  kelgia, fuss, modi4.  These systems are mainly concerned.

1 files changed, 31 insertions, 5 deletions

diff --git a/configure.in b/configure.in
index 3dfacbc..898bd18 100644
--- a/configure.in
+++ b/configure.in
@@ -2509,13 +2509,39 @@ fi
 
 dnl -----------------------------------------------------------------------
 dnl Set flag to indicate that the machine can handle conversion from 
-dnl long double to integers.  (This flag should be set "yes" for all 
-dnl machines except all SGIs and HP-UX 11.00, where some conversions are
+dnl long double to integers.  This flag should be set "yes" for all 
+dnl machines except all SGIs and HP-UX 11.00.  For SGIs, some conversions are
 dnl incorrect and its cache value is set "no" in its config/irix6.x and 
-dnl irix5.x and config/hpux11.00 files.) 
-dnl
+dnl irix5.x.  For HP-UX 11.00, the compiler has 'floating exception'
+dnl when converting 'long double' to all integers except 'unsigned long long'.
+dnl Other HP-UX systems are unknown yet. (1/8/05 - SLU)
+
 AC_MSG_CHECKING([if accurately converting from long double to integers works])
-AC_CACHE_VAL([hdf5_cv_sw_ldouble_to_integer_works], [hdf5_cv_sw_ldouble_to_integer_works=yes])
+
+AC_CACHE_VAL([hdf5_cv_sw_ldouble_to_integer_works],
+    [AC_TRY_RUN([
+    int main(void)
+    {
+        void *align;
+        long double ld= 9701917572145405952.00L;
+        unsigned char v1;
+        short v2;
+        unsigned int v3;
+        int  ret = 0;
+
+        align = (void*)malloc(sizeof(long double));
+        memcpy(align, &ld, sizeof(long double));
+
+        /*For HU-UX11.00, there's floating exception(core dump) when doing some of casting
+         *from 'long double' to integers*/
+        v1=(unsigned char)(*((long double*)align));
+        v2=(short)(*((long double*)align));
+        v3=(unsigned int)(*((long double*)align));
+
+done:
+        exit(ret);
+    }
+    ], [hdf5_cv_sw_ldouble_to_integer_works=yes], [hdf5_cv_sw_ldouble_to_integer_works=no],)])
 
 if test ${hdf5_cv_sw_ldouble_to_integer_works} = "yes"; then
   AC_DEFINE([SW_LDOUBLE_TO_INTEGER_WORKS], [1],