X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fisnand.m4;h=ee05e0f93ce4b4670ea465818fac30e80b68ecab;hb=5191b3546cfb6c163228c23f214e325ddf60d46f;hp=7783b424e618ee7add26ae5fd60be04bb6898ada;hpb=3e4b5182b4adda8d229d96e307a44a75eda086d3;p=gnulib.git diff --git a/m4/isnand.m4 b/m4/isnand.m4 index 7783b424e..ee05e0f93 100644 --- a/m4/isnand.m4 +++ b/m4/isnand.m4 @@ -1,144 +1,96 @@ -# isnand.m4 serial 2 -dnl Copyright (C) 2007-2008 Free Software Foundation, Inc. +# isnand.m4 serial 11 +dnl Copyright (C) 2007-2013 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. +dnl Check how to get or define isnand(). + +AC_DEFUN([gl_FUNC_ISNAND], +[ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + ISNAND_LIBM= + gl_HAVE_ISNAND_NO_LIBM + if test $gl_cv_func_isnand_no_libm = no; then + gl_HAVE_ISNAND_IN_LIBM + if test $gl_cv_func_isnand_in_libm = yes; then + ISNAND_LIBM=-lm + fi + fi + dnl The variable gl_func_isnand set here is used by isnan.m4. + if test $gl_cv_func_isnand_no_libm = yes \ + || test $gl_cv_func_isnand_in_libm = yes; then + gl_func_isnand=yes + else + gl_func_isnand=no + HAVE_ISNAND=0 + fi + AC_SUBST([ISNAND_LIBM]) +]) + dnl Check how to get or define isnand() without linking with libm. AC_DEFUN([gl_FUNC_ISNAND_NO_LIBM], [ - AC_CACHE_CHECK([whether isnan(double) can be used without linking with libm], - [gl_cv_func_isnand_no_libm], - [ - AC_TRY_LINK([#include - #if __GNUC__ >= 4 - # undef isnand - # define isnand(x) __builtin_isnan ((double)(x)) - #else - # undef isnand - # define isnand(x) isnan ((double)(x)) - #endif - double x;], - [return isnand (x);], - [gl_cv_func_isnand_no_libm=yes], - [gl_cv_func_isnand_no_libm=no]) - ]) + gl_HAVE_ISNAND_NO_LIBM + gl_func_isnand_no_libm=$gl_cv_func_isnand_no_libm if test $gl_cv_func_isnand_no_libm = yes; then - AC_DEFINE([HAVE_ISNAND_IN_LIBC], 1, + AC_DEFINE([HAVE_ISNAND_IN_LIBC], [1], [Define if the isnan(double) function is available in libc.]) - else - AC_LIBOBJ([isnand]) - gl_DOUBLE_EXPONENT_LOCATION fi ]) -AC_DEFUN([gl_DOUBLE_EXPONENT_LOCATION], +dnl Prerequisites of replacement isnand definition. It does not need -lm. +AC_DEFUN([gl_PREREQ_ISNAND], [ - AC_CACHE_CHECK([where to find the exponent in a 'double'], - [gl_cv_cc_double_expbit0], + AC_REQUIRE([gl_DOUBLE_EXPONENT_LOCATION]) +]) + +dnl Test whether isnand() can be used with libm. + +AC_DEFUN([gl_HAVE_ISNAND_IN_LIBM], +[ + AC_CACHE_CHECK([whether isnan(double) can be used with libm], + [gl_cv_func_isnand_in_libm], [ - AC_TRY_RUN([ -#include -#include -#include -#include -#define NWORDS \ - ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) -typedef union { double value; unsigned int word[NWORDS]; } memory_double; -static unsigned int ored_words[NWORDS]; -static unsigned int anded_words[NWORDS]; -static void add_to_ored_words (double x) -{ - memory_double m; - size_t i; - /* Clear it first, in case sizeof (double) < sizeof (memory_double). */ - memset (&m, 0, sizeof (memory_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 (0.25); - add_to_ored_words (0.5); - add_to_ored_words (1.0); - add_to_ored_words (2.0); - add_to_ored_words (4.0); - /* 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_double_expbit0=`cat conftest.out`], - [gl_cv_cc_double_expbit0="unknown"], - [ - dnl On ARM, there are two 'double' floating-point formats, used by - dnl different sets of instructions: The older FPA instructions assume - dnl that they are stored in big-endian word order, while the words - dnl (like integer types) are stored in little-endian byte order. - dnl The newer VFP instructions assume little-endian order consistenly. - AC_EGREP_CPP([mixed_endianness], [ -#if defined arm || defined __arm || defined __arm__ - mixed_endianness -#endif - ], - [gl_cv_cc_double_expbit0="unknown"], - [ - pushdef([AC_MSG_CHECKING],[:])dnl - pushdef([AC_MSG_RESULT],[:])dnl - pushdef([AC_MSG_RESULT_UNQUOTED],[:])dnl - AC_C_BIGENDIAN( - [gl_cv_cc_double_expbit0="word 0 bit 20"], - [gl_cv_cc_double_expbit0="word 1 bit 20"], - [gl_cv_cc_double_expbit0="unknown"]) - popdef([AC_MSG_RESULT_UNQUOTED])dnl - popdef([AC_MSG_RESULT])dnl - popdef([AC_MSG_CHECKING])dnl - ]) - ]) - rm -f conftest.out + save_LIBS="$LIBS" + LIBS="$LIBS -lm" + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include + #if __GNUC__ >= 4 + # undef isnand + # define isnand(x) __builtin_isnan ((double)(x)) + #elif defined isnan + # undef isnand + # define isnand(x) isnan ((double)(x)) + #endif + double x;]], + [[return isnand (x);]])], + [gl_cv_func_isnand_in_libm=yes], + [gl_cv_func_isnand_in_libm=no]) + LIBS="$save_LIBS" + ]) +]) + +AC_DEFUN([gl_HAVE_ISNAND_NO_LIBM], +[ + AC_CACHE_CHECK([whether isnan(double) can be used without linking with libm], + [gl_cv_func_isnand_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include + #if __GNUC__ >= 4 + # undef isnand + # define isnand(x) __builtin_isnan ((double)(x)) + #else + # undef isnand + # define isnand(x) isnan ((double)(x)) + #endif + double x;]], + [[return isnand (x);]])], + [gl_cv_func_isnand_no_libm=yes], + [gl_cv_func_isnand_no_libm=no]) ]) - case "$gl_cv_cc_double_expbit0" in - word*bit*) - word=`echo "$gl_cv_cc_double_expbit0" | sed -e 's/word //' -e 's/ bit.*//'` - bit=`echo "$gl_cv_cc_double_expbit0" | sed -e 's/word.*bit //'` - AC_DEFINE_UNQUOTED([DBL_EXPBIT0_WORD], [$word], - [Define as the word index where to find the exponent of 'double'.]) - AC_DEFINE_UNQUOTED([DBL_EXPBIT0_BIT], [$bit], - [Define as the bit index in the word where to find bit 0 of the exponent of 'double'.]) - ;; - esac ])