X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fisnanl.m4;h=25daecaedc3c24c0d4347a213b31dedd12aed0be;hb=217ec874c8e4610ce407f0204c4e3fe30b7c76ec;hp=a02ded78b84fe900a745415dba181bf9f3aad7d2;hpb=9fa5cba96b009df44348336ff6a4c091a2f859c5;p=gnulib.git diff --git a/m4/isnanl.m4 b/m4/isnanl.m4 index a02ded78b..25daecaed 100644 --- a/m4/isnanl.m4 +++ b/m4/isnanl.m4 @@ -1,11 +1,12 @@ -# isnanl.m4 serial 5 -dnl Copyright (C) 2007 Free Software Foundation, Inc. +# isnanl.m4 serial 12 +dnl Copyright (C) 2007-2010 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. AC_DEFUN([gl_FUNC_ISNANL], [ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) ISNANL_LIBM= gl_HAVE_ISNANL_NO_LIBM if test $gl_cv_func_isnanl_no_libm = no; then @@ -27,12 +28,9 @@ AC_DEFUN([gl_FUNC_ISNANL], else gl_func_isnanl=no fi - if test $gl_func_isnanl = yes; then - AC_DEFINE([HAVE_ISNANL], 1, - [Define if the isnan(long double) function is available.]) - else - AC_LIBOBJ([isnanl]) - gl_LONG_DOUBLE_EXPONENT_LOCATION + if test $gl_func_isnanl != yes; then + HAVE_ISNANL=0 + gl_BUILD_ISNANL fi AC_SUBST([ISNANL_LIBM]) ]) @@ -49,14 +47,20 @@ AC_DEFUN([gl_FUNC_ISNANL_NO_LIBM], esac fi if test $gl_func_isnanl_no_libm = yes; then - AC_DEFINE([HAVE_ISNANL_IN_LIBC], 1, + AC_DEFINE([HAVE_ISNANL_IN_LIBC], [1], [Define if the isnan(long double) function is available in libc.]) else - AC_LIBOBJ([isnanl]) - gl_LONG_DOUBLE_EXPONENT_LOCATION + gl_BUILD_ISNANL fi ]) +dnl Pull in replacement isnanl definition. It does not need -lm. +AC_DEFUN([gl_BUILD_ISNANL], +[ + AC_LIBOBJ([isnanl]) + gl_LONG_DOUBLE_EXPONENT_LOCATION +]) + dnl Test whether isnanl() can be used without libm. AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM], [ @@ -64,7 +68,10 @@ AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM], [gl_cv_func_isnanl_no_libm], [ AC_TRY_LINK([#include - #ifdef isnan + #if __GNUC__ >= 4 + # undef isnanl + # define isnanl(x) __builtin_isnanl ((long double)(x)) + #elif defined isnan # undef isnanl # define isnanl(x) isnan ((long double)(x)) #endif @@ -84,7 +91,10 @@ AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM], save_LIBS="$LIBS" LIBS="$LIBS -lm" AC_TRY_LINK([#include - #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 @@ -98,10 +108,13 @@ 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]) - AC_REQUIRE([AC_C_BIGENDIAN]) + AC_REQUIRE([gl_BIGENDIAN]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether isnanl works], [gl_cv_func_isnanl_works], [ @@ -109,7 +122,10 @@ AC_DEFUN([gl_FUNC_ISNANL_WORKS], #include #include #include -#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 @@ -117,16 +133,30 @@ AC_DEFUN([gl_FUNC_ISNANL_WORKS], ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) typedef union { unsigned int word[NWORDS]; long double value; } memory_long_double; +/* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the + runtime type conversion. */ +#ifdef __sgi +static long double NaNl () +{ + double zero = 0.0; + return zero / zero; +} +#else +# define NaNl() (0.0L / 0.0L) +#endif int main () { memory_long_double m; unsigned int i; + if (!isnanl (NaNl ())) + return 1; + /* The isnanl function should be immune against changes in the sign bit and in the mantissa bits. The xor operation twiddles a bit that can only be a sign bit or a mantissa bit (since the exponent never extends to bit 31). */ - m.value = 0.0L / 0.0L; + m.value = NaNl (); m.word[NWORDS / 2] ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1); for (i = 0; i < NWORDS; i++) m.word[i] |= 1; @@ -213,96 +243,3 @@ int main () ]) ]) ]) - -AC_DEFUN([gl_LONG_DOUBLE_EXPONENT_LOCATION], -[ - AC_REQUIRE([AC_C_BIGENDIAN]) - AC_CACHE_CHECK([where to find the exponent in a 'long double'], - [gl_cv_cc_long_double_expbit0], - [ - AC_TRY_RUN([ -#include -#include -#include -#include -#define NWORDS \ - ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) -typedef union { long double value; unsigned int word[NWORDS]; } - memory_long_double; -static unsigned int ored_words[NWORDS]; -static unsigned int anded_words[NWORDS]; -static void add_to_ored_words (long double x) -{ - memory_long_double m; - size_t i; - /* Clear it first, in case - sizeof (long double) < sizeof (memory_long_double). */ - memset (&m, 0, sizeof (memory_long_double)); - m.value = x; - for (i = 0; i < NWORDS; i++) - { - ored_words[i] |= m.word[i]; - anded_words[i] &= m.word[i]; - } -} -int main () -{ - size_t j; - FILE *fp = fopen ("conftest.out", "w"); - if (fp == NULL) - return 1; - for (j = 0; j < NWORDS; j++) - anded_words[j] = ~ (unsigned int) 0; - add_to_ored_words (0.25L); - add_to_ored_words (0.5L); - add_to_ored_words (1.0L); - add_to_ored_words (2.0L); - add_to_ored_words (4.0L); - /* Remove bits that are common (e.g. if representation of the first mantissa - bit is explicit). */ - for (j = 0; j < NWORDS; j++) - ored_words[j] &= ~anded_words[j]; - /* Now find the nonzero word. */ - for (j = 0; j < NWORDS; j++) - if (ored_words[j] != 0) - break; - if (j < NWORDS) - { - size_t i; - for (i = j + 1; i < NWORDS; i++) - if (ored_words[i] != 0) - { - fprintf (fp, "unknown"); - return (fclose (fp) != 0); - } - for (i = 0; ; i++) - if ((ored_words[j] >> i) & 1) - { - fprintf (fp, "word %d bit %d", (int) j, (int) i); - return (fclose (fp) != 0); - } - } - fprintf (fp, "unknown"); - return (fclose (fp) != 0); -} - ], - [gl_cv_cc_long_double_expbit0=`cat conftest.out`], - [gl_cv_cc_long_double_expbit0="unknown"], - [ - dnl When cross-compiling, we don't know. It depends on the - dnl ABI and compiler version. There are too many cases. - gl_cv_cc_long_double_expbit0="unknown" - ]) - rm -f conftest.out - ]) - case "$gl_cv_cc_long_double_expbit0" in - word*bit*) - word=`echo "$gl_cv_cc_long_double_expbit0" | sed -e 's/word //' -e 's/ bit.*//'` - bit=`echo "$gl_cv_cc_long_double_expbit0" | sed -e 's/word.*bit //'` - AC_DEFINE_UNQUOTED([LDBL_EXPBIT0_WORD], [$word], - [Define as the word index where to find the exponent of 'long double'.]) - AC_DEFINE_UNQUOTED([LDBL_EXPBIT0_BIT], [$bit], - [Define as the bit index in the word where to find bit 0 of the exponent of 'long double'.]) - ;; - esac -])