Mercurial > gnulib
view m4/logbl.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 | b06060465f09 |
children |
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# logbl.m4 serial 5 dnl Copyright (C) 2012-2019 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_LOGBL], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) AC_REQUIRE([gl_FUNC_LOGB]) dnl Persuade glibc <math.h> to declare logbl(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) dnl Test whether logbl() exists and determine LOGBL_LIBM. We cannot assume dnl that logbl(), if it exists, is defined in the same library as logb(). dnl This is not the case on AIX >= 5.2, Solaris >= 10. gl_MATHFUNC([logbl], [long double], [(long double)]) if test $gl_cv_func_logbl_no_libm = yes \ || test $gl_cv_func_logbl_in_libm = yes; then save_LIBS="$LIBS" LIBS="$LIBS $LOGBL_LIBM" gl_FUNC_LOGBL_WORKS LIBS="$save_LIBS" case "$gl_cv_func_logbl_works" in *yes) ;; *) REPLACE_LOGBL=1 ;; esac else HAVE_LOGBL=0 fi if test $HAVE_LOGBL = 0 || test $REPLACE_LOGBL = 1; then dnl Find libraries needed to link lib/logbl.c. if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then LOGBL_LIBM="$LOGB_LIBM" else AC_REQUIRE([gl_FUNC_FREXPL]) AC_REQUIRE([gl_FUNC_ISNANL]) LOGBL_LIBM= dnl Append $FREXPL_LIBM to LOGBL_LIBM, avoiding gratuitous duplicates. case " $LOGBL_LIBM " in *" $FREXPL_LIBM "*) ;; *) LOGBL_LIBM="$LOGBL_LIBM $FREXPL_LIBM" ;; esac dnl Append $ISNANL_LIBM to LOGBL_LIBM, avoiding gratuitous duplicates. case " $LOGBL_LIBM " in *" $ISNANL_LIBM "*) ;; *) LOGBL_LIBM="$LOGBL_LIBM $ISNANL_LIBM" ;; esac fi fi AC_SUBST([LOGBL_LIBM]) ]) dnl Test whether logbl() works. dnl On glibc 2.11/powerpc, glibc 2.7/sparc, glibc 2.7/hppa, Solaris 10/SPARC, dnl Solaris 11.4/x86_64, the return value for subnormal (denormalized) arguments dnl is too large. dnl On glibc 2.23/powerpc64le, the return value for negative subnormal arguments dnl is too large. AC_DEFUN([gl_FUNC_LOGBL_WORKS], [ AC_REQUIRE([AC_PROG_CC]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether logbl works], [gl_cv_func_logbl_works], [ AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #include <float.h> #include <math.h> /* Override the values of <float.h>, like done in float.in.h. */ #if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__) # undef LDBL_MIN_EXP # define LDBL_MIN_EXP (-16381) #endif #if defined __i386__ && (defined __FreeBSD__ || defined __DragonFly__) # undef LDBL_MIN_EXP # define LDBL_MIN_EXP (-16381) #endif #if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__ # undef LDBL_MIN_EXP # define LDBL_MIN_EXP DBL_MIN_EXP #endif #if defined __sgi && (LDBL_MANT_DIG >= 106) # if defined __GNUC__ # undef LDBL_MIN_EXP # define LDBL_MIN_EXP DBL_MIN_EXP # endif #endif volatile long double x; int main () { int i; for (i = 1, x = 1.0L; i >= LDBL_MIN_EXP - 54; i--, x *= 0.5L) /* Either x = 2^(i-1) or x = 0.0. */ if ((i == LDBL_MIN_EXP - 1 || i == LDBL_MIN_EXP - 54) && (x > 0.0L && !(logbl (x) == (long double)(i - 1)))) return 1; for (i = 1, x = -1.0L; i >= LDBL_MIN_EXP - 54; i--, x *= 0.5L) /* Either x = -2^(i-1) or x = 0.0. */ if ((i == LDBL_MIN_EXP - 1 || i == LDBL_MIN_EXP - 54) && (x < 0.0L && !(logbl (x) == (long double)(i - 1)))) return 1; return 0; } ]])], [gl_cv_func_logbl_works=yes], [gl_cv_func_logbl_works=no], [case "$host_os" in *gnu* | solaris*) gl_cv_func_logbl_works="guessing no" ;; # Guess yes on native Windows. mingw*) gl_cv_func_logbl_works="guessing yes" ;; *) gl_cv_func_logbl_works="guessing yes" ;; esac ]) ]) ])