Mercurial > gnulib
view m4/expl.m4 @ 40177:dcd889592b62
dtoastr,ftoastr,ldtoastr: port to c-strtod changes
Decouple these modules from c-strtod. Nowadays it’s reasonable to
assume the C99 signatures for strtod and strtold. Programs that
require stricter adherence to C99 should also use the strtod and
strtold modules as needed, and we no longer need the
HAVE_C99_STRTOLD macro.
* NEWS: Mention this.
* lib/ftoastr.c (STRTOF) [LENGTH == 3]: Assume strtold.
* m4/c-strtod.m4 (gl_C_STRTOLD): Do not define HAVE_C99_STRTOLD.
* modules/dtoastr, modules/ftoastr, modules/ldtoastr:
(Files): Remove m4/c-strtod.m4.
(configure.ac): Do not require gl_C99_STRTOLD, which no longer
exists.
author | Paul Eggert <eggert@cs.ucla.edu> |
---|---|
date | Sat, 02 Feb 2019 13:01:55 -0800 |
parents | cccb8f07c744 |
children |
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# expl.m4 serial 12 dnl Copyright (C) 2010-2019 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_EXPL], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles dnl Persuade glibc <math.h> to declare expl(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) EXPL_LIBM= AC_CACHE_CHECK([whether expl() can be used without linking with libm], [gl_cv_func_expl_no_libm], [ AC_LINK_IFELSE( [AC_LANG_PROGRAM( [[#ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include <math.h> long double (*funcptr) (long double) = expl; long double x;]], [[return funcptr (x) > 1.5 || expl (x) > 1.5;]])], [gl_cv_func_expl_no_libm=yes], [gl_cv_func_expl_no_libm=no]) ]) if test $gl_cv_func_expl_no_libm = no; then AC_CACHE_CHECK([whether expl() can be used with libm], [gl_cv_func_expl_in_libm], [ save_LIBS="$LIBS" LIBS="$LIBS -lm" AC_LINK_IFELSE( [AC_LANG_PROGRAM( [[#ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include <math.h> long double (*funcptr) (long double) = expl; long double x;]], [[return funcptr (x) > 1.5 || expl (x) > 1.5;]])], [gl_cv_func_expl_in_libm=yes], [gl_cv_func_expl_in_libm=no]) LIBS="$save_LIBS" ]) if test $gl_cv_func_expl_in_libm = yes; then EXPL_LIBM=-lm fi fi dnl On Haiku 2017 the system's native expl() is just a stub: it returns 0.0 dnl and prints "__expl not implemented" for all arguments. dnl On OpenBSD 5.4 the system's native expl() is buggy: dnl it returns 'nan' for small values. Test for this anomaly. if test $gl_cv_func_expl_no_libm = yes \ || test $gl_cv_func_expl_in_libm = yes; then AC_CACHE_CHECK([whether expl() breaks with small values], [gl_cv_func_expl_buggy], [save_LIBS="$LIBS" LIBS="$EXPL_LIBM" AC_RUN_IFELSE( [AC_LANG_PROGRAM( [[#include <math.h>]], [[volatile long double x1 = -1.0; volatile long double x2 = -0.8; volatile long double x3 = -0.4; return expl(x1) == 0.0 || isnan(expl(x1)) || isnan(expl(x2)) || isnan(expl(x3)); ]]) ], [gl_cv_func_expl_buggy=no], [gl_cv_func_expl_buggy=yes], [case $host_os in haiku* | openbsd*) gl_cv_func_expl_buggy="guessing yes" ;; # Guess no on native Windows. mingw*) gl_cv_func_expl_buggy="guessing no" ;; *) gl_cv_func_expl_buggy="guessing no" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_expl_buggy" in *yes) gl_cv_func_expl_in_libm=no gl_cv_func_expl_no_libm=no ;; esac fi if test $gl_cv_func_expl_no_libm = yes \ || test $gl_cv_func_expl_in_libm = yes; then dnl Also check whether it's declared. dnl Mac OS X 10.3 has expl() in libc but doesn't declare it in <math.h>. AC_CHECK_DECL([expl], , [HAVE_DECL_EXPL=0], [[#include <math.h>]]) if test $REPLACE_EXPL = 0; then AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether expl works], [gl_cv_func_expl_works], [ save_LIBS="$LIBS" LIBS="$LIBS $EXPL_LIBM" AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #ifndef __NO_MATH_INLINES # define __NO_MATH_INLINES 1 /* for glibc */ #endif #include <float.h> #include <math.h> /* Override the values of <float.h>, like done in float.in.h. */ #if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__) # undef LDBL_MANT_DIG # define LDBL_MANT_DIG 64 # undef LDBL_MIN_EXP # define LDBL_MIN_EXP (-16381) # undef LDBL_MAX_EXP # define LDBL_MAX_EXP 16384 #endif #if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__) # undef LDBL_MANT_DIG # define LDBL_MANT_DIG 64 # undef LDBL_MIN_EXP # define LDBL_MIN_EXP (-16381) # undef LDBL_MAX_EXP # define LDBL_MAX_EXP 16384 #endif #if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__ # undef LDBL_MIN_EXP # define LDBL_MIN_EXP DBL_MIN_EXP #endif #if defined __sgi && (LDBL_MANT_DIG >= 106) # undef LDBL_MANT_DIG # define LDBL_MANT_DIG 106 # if defined __GNUC__ # undef LDBL_MIN_EXP # define LDBL_MIN_EXP DBL_MIN_EXP # endif #endif #undef expl extern #ifdef __cplusplus "C" #endif long double expl (long double); static long double dummy (long double x) { return 0; } int main (int argc, char *argv[]) { long double (* volatile my_expl) (long double) = argc ? expl : dummy; int result = 0; /* This test fails on NetBSD 8.0. */ { const long double TWO_LDBL_MANT_DIG = /* 2^LDBL_MANT_DIG */ (long double) (1U << ((LDBL_MANT_DIG - 1) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 1) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 2) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 3) / 5)) * (long double) (1U << ((LDBL_MANT_DIG - 1 + 4) / 5)); long double x = 11.358L; long double err = (my_expl (x) * my_expl (- x) - 1.0L) * TWO_LDBL_MANT_DIG; if (!(err >= -100.0L && err <= 100.0L)) result |= 1; } return result; } ]])], [gl_cv_func_expl_works=yes], [gl_cv_func_expl_works=no], [case "$host_os" in # Guess yes on glibc systems. *-gnu* | gnu*) gl_cv_func_expl_works="guessing yes" ;; # Guess yes on native Windows. mingw*) gl_cv_func_expl_works="guessing yes" ;; # If we don't know, assume the worst. *) gl_cv_func_expl_works="guessing no" ;; esac ]) LIBS="$save_LIBS" ]) case "$gl_cv_func_expl_works" in *yes) ;; *) REPLACE_EXPL=1 ;; esac fi else HAVE_DECL_EXPL=0 HAVE_EXPL=0 fi if test $HAVE_EXPL = 0 || test $REPLACE_EXPL = 1; then dnl Find libraries needed to link lib/expl.c. if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then AC_REQUIRE([gl_FUNC_EXP]) EXPL_LIBM="$EXP_LIBM" else AC_REQUIRE([gl_FUNC_ISNANL]) AC_REQUIRE([gl_FUNC_ROUNDL]) AC_REQUIRE([gl_FUNC_LDEXPL]) EXPL_LIBM= dnl Append $ISNANL_LIBM to EXPL_LIBM, avoiding gratuitous duplicates. case " $EXPL_LIBM " in *" $ISNANL_LIBM "*) ;; *) EXPL_LIBM="$EXPL_LIBM $ISNANL_LIBM" ;; esac dnl Append $ROUNDL_LIBM to EXPL_LIBM, avoiding gratuitous duplicates. case " $EXPL_LIBM " in *" $ROUNDL_LIBM "*) ;; *) EXPL_LIBM="$EXPL_LIBM $ROUNDL_LIBM" ;; esac dnl Append $LDEXPL_LIBM to EXPL_LIBM, avoiding gratuitous duplicates. case " $EXPL_LIBM " in *" $LDEXPL_LIBM "*) ;; *) EXPL_LIBM="$EXPL_LIBM $LDEXPL_LIBM" ;; esac fi fi AC_SUBST([EXPL_LIBM]) ])