# frexpl.m4 # serial 24 dnl Copyright (C) 2007-2024 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_FREXPL], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) dnl Persuade glibc to declare frexpl(). AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) dnl Check whether it's declared. dnl Mac OS X 10.3 has frexpl() in libc but doesn't declare it in . AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include ]]) FREXPL_LIBM= if test $HAVE_DECL_FREXPL = 1; then gl_CHECK_FREXPL_NO_LIBM if test $gl_cv_func_frexpl_no_libm = no; then AC_CACHE_CHECK([whether frexpl() can be used with libm], [gl_cv_func_frexpl_in_libm], [ saved_LIBS="$LIBS" LIBS="$LIBS -lm" AC_LINK_IFELSE( [AC_LANG_PROGRAM( [[#include long double x;]], [[int e; return frexpl (x, &e) > 0;]])], [gl_cv_func_frexpl_in_libm=yes], [gl_cv_func_frexpl_in_libm=no]) LIBS="$saved_LIBS" ]) if test $gl_cv_func_frexpl_in_libm = yes; then FREXPL_LIBM=-lm fi fi if test $gl_cv_func_frexpl_no_libm = yes \ || test $gl_cv_func_frexpl_in_libm = yes; then saved_LIBS="$LIBS" LIBS="$LIBS $FREXPL_LIBM" gl_FUNC_FREXPL_WORKS LIBS="$saved_LIBS" case "$gl_cv_func_frexpl_works" in *yes) gl_func_frexpl=yes ;; *) gl_func_frexpl=no; REPLACE_FREXPL=1 ;; esac else gl_func_frexpl=no fi if test $gl_func_frexpl = yes; then AC_DEFINE([HAVE_FREXPL], [1], [Define if the frexpl() function is available.]) fi fi if test $HAVE_DECL_FREXPL = 0 || test $gl_func_frexpl = no; then dnl Find libraries needed to link lib/frexpl.c. if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then AC_REQUIRE([gl_FUNC_FREXP]) FREXPL_LIBM="$FREXP_LIBM" else FREXPL_LIBM= fi fi AC_SUBST([FREXPL_LIBM]) ]) AC_DEFUN([gl_FUNC_FREXPL_NO_LIBM], [ AC_REQUIRE([gl_MATH_H_DEFAULTS]) AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) dnl Check whether it's declared. dnl Mac OS X 10.3 has frexpl() in libc but doesn't declare it in . AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include ]]) if test $HAVE_DECL_FREXPL = 1; then gl_CHECK_FREXPL_NO_LIBM if test $gl_cv_func_frexpl_no_libm = yes; then gl_FUNC_FREXPL_WORKS case "$gl_cv_func_frexpl_works" in *yes) gl_func_frexpl_no_libm=yes ;; *) gl_func_frexpl_no_libm=no; REPLACE_FREXPL=1 ;; esac else gl_func_frexpl_no_libm=no dnl Set REPLACE_FREXPL here because the system may have frexpl in libm. REPLACE_FREXPL=1 fi if test $gl_func_frexpl_no_libm = yes; then AC_DEFINE([HAVE_FREXPL_IN_LIBC], [1], [Define if the frexpl() function is available in libc.]) fi fi ]) dnl Test whether frexpl() can be used without linking with libm. dnl Set gl_cv_func_frexpl_no_libm to 'yes' or 'no' accordingly. AC_DEFUN([gl_CHECK_FREXPL_NO_LIBM], [ AC_CACHE_CHECK([whether frexpl() can be used without linking with libm], [gl_cv_func_frexpl_no_libm], [ AC_LINK_IFELSE( [AC_LANG_PROGRAM( [[#include long double x;]], [[int e; return frexpl (x, &e) > 0;]])], [gl_cv_func_frexpl_no_libm=yes], [gl_cv_func_frexpl_no_libm=no]) ]) ]) dnl Test whether frexpl() works on finite numbers (this fails on dnl Mac OS X 10.4/PowerPC, on AIX 5.1, and on BeOS), on denormalized numbers dnl (this fails on Mac OS X 10.5/i386), and also on infinite numbers (this dnl fails e.g. on IRIX 6.5 and mingw). AC_DEFUN([gl_FUNC_FREXPL_WORKS], [ AC_REQUIRE([AC_PROG_CC]) AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles AC_CACHE_CHECK([whether frexpl works], [gl_cv_func_frexpl_works], [ AC_RUN_IFELSE( [AC_LANG_SOURCE([[ #include #include /* Override the values of , 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 extern #ifdef __cplusplus "C" #endif long double frexpl (long double, int *); long double zero = 0.0L; int main() { int result = 0; volatile long double x; /* Test on finite numbers that fails on AIX 5.1. */ x = 16.0L; { int exp = -9999; frexpl (x, &exp); if (exp != 5) result |= 1; } /* Test on finite numbers that fails on Mac OS X 10.4, because its frexpl function returns an invalid (incorrectly normalized) value: it returns y = { 0x3fe028f5, 0xc28f5c28, 0x3c9eb851, 0xeb851eb8 } but the correct result is 0.505L = { 0x3fe028f5, 0xc28f5c29, 0xbc547ae1, 0x47ae1480 } */ x = 1.01L; { int exp = -9999; long double y = frexpl (x, &exp); if (!(exp == 1 && y == 0.505L)) result |= 2; } /* Test on large finite numbers. This fails on BeOS at i = 16322, while LDBL_MAX_EXP = 16384. In the loop end test, we test x against Infinity, rather than comparing i with LDBL_MAX_EXP, because BeOS has a wrong LDBL_MAX_EXP. */ { int i; for (i = 1, x = 1.0L; x != x + x; i++, x *= 2.0L) { int exp = -9999; frexpl (x, &exp); if (exp != i) { result |= 4; break; } } } /* Test on denormalized numbers. */ { int i; for (i = 1, x = 1.0L; i >= LDBL_MIN_EXP; i--, x *= 0.5L) ; if (x > 0.0L) { int exp; long double y = frexpl (x, &exp); /* On machines with IEEE854 arithmetic: x = 1.68105e-4932, exp = -16382, y = 0.5. On Mac OS X 10.5: exp = -16384, y = 0.5. */ if (exp != LDBL_MIN_EXP - 1) result |= 8; } } /* Test on infinite numbers. */ /* The Microsoft MSVC 14 compiler chokes on the expression 1.0 / 0.0. */ x = 1.0L / zero; { int exp; long double y = frexpl (x, &exp); if (y != x) result |= 16; } return result; }]])], [gl_cv_func_frexpl_works=yes], [gl_cv_func_frexpl_works=no], [ changequote(,)dnl case "$host_os" in aix | aix[3-6]* | beos* | darwin* | irix* | mingw* | windows* | pw*) gl_cv_func_frexpl_works="guessing no";; *) gl_cv_func_frexpl_works="guessing yes";; esac changequote([,])dnl ]) ]) ])