diff options
Diffstat (limited to 'm4/isnanl.m4')
| -rw-r--r-- | m4/isnanl.m4 | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/m4/isnanl.m4 b/m4/isnanl.m4 index a02ded78b8..c2bddc665a 100644 --- a/m4/isnanl.m4 +++ b/m4/isnanl.m4 @@ -1,5 +1,5 @@ -# isnanl.m4 serial 5 -dnl Copyright (C) 2007 Free Software Foundation, Inc. +# isnanl.m4 serial 6 +dnl Copyright (C) 2007-2008 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. @@ -64,7 +64,10 @@ AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM], [gl_cv_func_isnanl_no_libm], [ AC_TRY_LINK([#include <math.h> - #ifdef isnan + #if __GNUC__ >= 4 + # undef isnanl + # define isnanl(x) __builtin_isnanl ((long double)(x)) + #elif defined isnan # undef isnanl # define isnanl(x) isnan ((long double)(x)) #endif @@ -84,7 +87,10 @@ AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM], save_LIBS="$LIBS" LIBS="$LIBS -lm" AC_TRY_LINK([#include <math.h> - #ifdef isnan + #if __GNUC__ >= 4 + # undef isnanl + # define isnanl(x) __builtin_isnanl ((long double)(x)) + #elif defined isnan # undef isnanl # define isnanl(x) isnan ((long double)(x)) #endif @@ -98,6 +104,9 @@ AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM], dnl Test whether isnanl() recognizes all numbers which are neither finite nor dnl infinite. This test fails e.g. on NetBSD/i386 and on glibc/ia64. +dnl Also, the GCC >= 4.0 built-in __builtin_isnanl does not pass the tests +dnl - for pseudo-denormals on i686 and x86_64, +dnl - for pseudo-zeroes, unnormalized numbers, and pseudo-denormals on ia64. AC_DEFUN([gl_FUNC_ISNANL_WORKS], [ AC_REQUIRE([AC_PROG_CC]) @@ -109,7 +118,10 @@ AC_DEFUN([gl_FUNC_ISNANL_WORKS], #include <float.h> #include <limits.h> #include <math.h> -#ifdef isnan +#if __GNUC__ >= 4 +# undef isnanl +# define isnanl(x) __builtin_isnanl ((long double)(x)) +#elif defined isnan # undef isnanl # define isnanl(x) isnan ((long double)(x)) #endif |