| # frexpl.m4 serial 22 |
| dnl Copyright (C) 2007-2021 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 <math.h> 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 <math.h>. |
| AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include <math.h>]]) |
| |
| FREXPL_LIBM= |
| if test $HAVE_DECL_FREXPL = 1; then |
| gl_CHECK_FREXPL_NO_LIBM |
| if test $gl_cv_func_frexpl_no_libm = no; then |
| AC_CACHE_CHECK([whether frexpl() can be used with libm], |
| [gl_cv_func_frexpl_in_libm], |
| [ |
| save_LIBS="$LIBS" |
| LIBS="$LIBS -lm" |
| AC_LINK_IFELSE( |
| [AC_LANG_PROGRAM( |
| [[#include <math.h> |
| long double x;]], |
| [[int e; return frexpl (x, &e) > 0;]])], |
| [gl_cv_func_frexpl_in_libm=yes], |
| [gl_cv_func_frexpl_in_libm=no]) |
| LIBS="$save_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 $gl_cv_func_frexpl_in_libm = yes; then |
| save_LIBS="$LIBS" |
| LIBS="$LIBS $FREXPL_LIBM" |
| gl_FUNC_FREXPL_WORKS |
| LIBS="$save_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 <math.h>. |
| AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include <math.h>]]) |
| 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 <math.h> |
| 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 <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 |
| 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 <float.h> 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* | pw*) |
| gl_cv_func_frexpl_works="guessing no";; |
| *) gl_cv_func_frexpl_works="guessing yes";; |
| esac |
| changequote([,])dnl |
| ]) |
| ]) |
| ]) |
