diff options
Diffstat (limited to 'configure.in')
| -rw-r--r-- | configure.in | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/configure.in b/configure.in index 358b5ce..e70346d 100644 --- a/configure.in +++ b/configure.in @@ -3157,6 +3157,71 @@ else fi dnl ---------------------------------------------------------------------- +dnl Set the flag to indicate that the machine can accurately convert +dnl '(unsigned) long long' to 'long double' values. (This flag should be set for +dnl all machines, except for Mac OS 10.4, when the bit sequences are 003fff..., +dnl 007fff..., 00ffff..., 01ffff..., ..., 7fffff..., the converted values are twice +dnl as big as they should be. +dnl +AC_MSG_CHECKING([if correctly converting (unsigned) long long to long double values]) + +if test ${ac_cv_sizeof_long_double} = 0; then + hdf5_llong_to_ldouble_correct=${hdf5_llong_to_ldouble_correct=no} +else + AC_CACHE_VAL([hdf5_llong_to_ldouble_correct], + [AC_TRY_RUN([ + int main(void) + { + long double ld; + long long ll; + unsigned long long ull; + unsigned char s[16]; + int flag=0, ret=0; + + /*Determine if long double has 16 byte in size, 11 bit exponent, and + *the bias is 0x3ff */ + if(sizeof(long double) == 16) { + ld = 1.0L; + memcpy(s, &ld, 16); + if(s[0]==0x3f && s[1]==0xf0 && s[2]==0x00 && s[3]==0x00 && + s[4]==0x00 && s[5]==0x00 && s[6]==0x00 && s[7]==0x00) + flag = 1; + } + + if(flag==1 && sizeof(long long)==8) { + ll = 0x01ffffffffffffffLL; + ld = (long double)ll; + memcpy(s, &ld, 16); + /*Check if the bit sequence is as supposed to be*/ + if(s[0]!=0x43 || s[1]!=0x7f || s[2]!=0xff || s[3]!=0xff || + s[4]!=0xff || s[5]!=0xff || s[6]!=0xff || s[7]!=0xff || + s[8]!=0xf0 || s[9]!=0x00 || s[10]!=0x00 || s[11]!=0x00) + ret = 1; + } + if(flag==1 && sizeof(unsigned long long)==8) { + ull = 0x01ffffffffffffffULL; + ld = (long double)ull; + memcpy(s, &ld, 16); + if(s[0]!=0x43 || s[1]!=0x7f || s[2]!=0xff || s[3]!=0xff || + s[4]!=0xff || s[5]!=0xff || s[6]!=0xff || s[7]!=0xff || + s[8]!=0xf0 || s[9]!=0x00 || s[10]!=0x00 || s[11]!=0x00) + ret = 1; + } + done: + exit(ret); + } + ], [hdf5_llong_to_ldouble_correct=yes], [hdf5_llong_to_ldouble_correct=no],)]) +fi + +if test ${hdf5_llong_to_ldouble_correct} = "yes"; then + AC_DEFINE([LLONG_TO_LDOUBLE_CORRECT], [1], + [Define if your system can convert (unsigned) long long to long double values correctly.]) + 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 |