diff options
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 51 |
1 files changed, 40 insertions, 11 deletions
diff --git a/configure.ac b/configure.ac index 7b944d92a..10368870f 100644 --- a/configure.ac +++ b/configure.ac @@ -252,6 +252,40 @@ AC_LANG(C) dnl Support unusual archivers. AM_PROG_AR +dnl Try to determine the double format +AC_MSG_CHECKING(format of `double') +AC_RUN_IFELSE([AC_LANG_PROGRAM([[ +#include <stdint.h> +]], [[ +union ieee_double_extract +{ + double d; + uint32_t x[2]; +} t; +t.d = 1.000000476837158203125; /* 1 + 1/2^21, which has manl = 2^31, + manh = 0, exp = 1023 and sig = 0 */ +if (t.x[0] == 2147483648UL && t.x[1] == 1072693248UL) + return 1; /* little endian */ +else if (t.x[0] == 1072693248UL && t.x[1] == 2147483648UL) + return 2; /* little endian swapped */ +else if (t.x[0] == 1024 && t.x[1] == 2147483648UL) + return 3; /* big endian */ +else + return 0; /* unknown */ +]])], + [mpfr_ieee_double=$?], + [mpfr_ieee_double=$?], + [mpfr_ieee_double=0]) +case "$mpfr_ieee_double" in + 1) AC_MSG_RESULT(little endian) + AC_DEFINE(HAVE_DOUBLE_IEEE_LITTLE_ENDIAN) ;; + 2) AC_MSG_RESULT(little endian swapped) + AC_DEFINE(HAVE_DOUBLE_IEEE_LITTLE_SWAPPED) ;; + 3) AC_MSG_RESULT(big endian) + AC_DEFINE(HAVE_DOUBLE_IEEE_BIG_ENDIAN) ;; + *) AC_MSG_ERROR(format of 'double' not recognized) ;; +esac + dnl For GCC, _Decimal64 was introduced in GCC 4.3 for some targets dnl (note that it is not guaranteed to be available because it may dnl be disabled in the GCC build). See: @@ -270,17 +304,12 @@ AC_ARG_ENABLE(decimal-float, AC_MSG_CHECKING(if compiler knows _Decimal64) AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[_Decimal64 x;]])], [AC_MSG_RESULT(yes) - if test "$use_gmp_build" != yes ; then - AC_MSG_ERROR([decimal float support requires --with-gmp-build]) - fi - AC_MSG_CHECKING(if _GMP_IEEE_FLOATS is defined) - AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ -#include "gmp.h" -#include "gmp-impl.h" -#ifndef _GMP_IEEE_FLOATS -#error "_GMP_IEEE_FLOATS is not defined" -#endif]])],[AC_MSG_RESULT(yes)],[AC_MSG_RESULT(no) - AC_MSG_ERROR([decimal float support requires _GMP_IEEE_FLOATS])]) + AC_MSG_CHECKING(if 'double' format is known) + case $mpfr_ieee_double in + 0) AC_MSG_RESULT(no) + AC_MSG_ERROR([unknown 'double' format]) ;; + *) AC_MSG_RESULT(yes) + esac ], [AC_MSG_RESULT(no) AC_MSG_ERROR([Compiler doesn't know _Decimal64 (ISO/IEC TR 24732). |