1 # frexpl.m4 serial 20 2 dnl Copyright (C) 2007-2012 Free Software Foundation, Inc. 3 dnl This file is free software; the Free Software Foundation 4 dnl gives unlimited permission to copy and/or distribute it, 5 dnl with or without modifications, as long as this notice is preserved. 6 7 AC_DEFUN([gl_FUNC_FREXPL], 8 [ 9 AC_REQUIRE([gl_MATH_H_DEFAULTS]) 10 AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) 11 12 dnl Persuade glibc <math.h> to declare frexpl(). 13 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) 14 15 dnl Check whether it's declared. 16 dnl Mac OS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>. 17 AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include <math.h>]]) 18 19 FREXPL_LIBM= 20 if test $HAVE_DECL_FREXPL = 1; then 21 gl_CHECK_FREXPL_NO_LIBM 22 if test $gl_cv_func_frexpl_no_libm = no; then 23 AC_CACHE_CHECK([whether frexpl() can be used with libm], 24 [gl_cv_func_frexpl_in_libm], 25 [ 26 save_LIBS="$LIBS" 27 LIBS="$LIBS -lm" 28 AC_LINK_IFELSE( 29 [AC_LANG_PROGRAM( 30 [[#include <math.h> 31 long double x;]], 32 [[int e; return frexpl (x, &e) > 0;]])], 33 [gl_cv_func_frexpl_in_libm=yes], 34 [gl_cv_func_frexpl_in_libm=no]) 35 LIBS="$save_LIBS" 36 ]) 37 if test $gl_cv_func_frexpl_in_libm = yes; then 38 FREXPL_LIBM=-lm 39 fi 40 fi 41 if test $gl_cv_func_frexpl_no_libm = yes \ 42 || test $gl_cv_func_frexpl_in_libm = yes; then 43 save_LIBS="$LIBS" 44 LIBS="$LIBS $FREXPL_LIBM" 45 gl_FUNC_FREXPL_WORKS 46 LIBS="$save_LIBS" 47 case "$gl_cv_func_frexpl_works" in 48 *yes) gl_func_frexpl=yes ;; 49 *) gl_func_frexpl=no; REPLACE_FREXPL=1 ;; 50 esac 51 else 52 gl_func_frexpl=no 53 fi 54 if test $gl_func_frexpl = yes; then 55 AC_DEFINE([HAVE_FREXPL], [1], 56 [Define if the frexpl() function is available.]) 57 fi 58 fi 59 if test $HAVE_DECL_FREXPL = 0 || test $gl_func_frexpl = no; then 60 dnl Find libraries needed to link lib/frexpl.c. 61 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then 62 AC_REQUIRE([gl_FUNC_FREXP]) 63 FREXPL_LIBM="$FREXP_LIBM" 64 else 65 FREXPL_LIBM= 66 fi 67 fi 68 AC_SUBST([FREXPL_LIBM]) 69 ]) 70 71 AC_DEFUN([gl_FUNC_FREXPL_NO_LIBM], 72 [ 73 AC_REQUIRE([gl_MATH_H_DEFAULTS]) 74 AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) 75 dnl Check whether it's declared. 76 dnl Mac OS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>. 77 AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [[#include <math.h>]]) 78 if test $HAVE_DECL_FREXPL = 1; then 79 gl_CHECK_FREXPL_NO_LIBM 80 if test $gl_cv_func_frexpl_no_libm = yes; then 81 gl_FUNC_FREXPL_WORKS 82 case "$gl_cv_func_frexpl_works" in 83 *yes) gl_func_frexpl_no_libm=yes ;; 84 *) gl_func_frexpl_no_libm=no; REPLACE_FREXPL=1 ;; 85 esac 86 else 87 gl_func_frexpl_no_libm=no 88 dnl Set REPLACE_FREXPL here because the system may have frexpl in libm. 89 REPLACE_FREXPL=1 90 fi 91 if test $gl_func_frexpl_no_libm = yes; then 92 AC_DEFINE([HAVE_FREXPL_IN_LIBC], [1], 93 [Define if the frexpl() function is available in libc.]) 94 fi 95 fi 96 ]) 97 98 dnl Test whether frexpl() can be used without linking with libm. 99 dnl Set gl_cv_func_frexpl_no_libm to 'yes' or 'no' accordingly. 100 AC_DEFUN([gl_CHECK_FREXPL_NO_LIBM], 101 [ 102 AC_CACHE_CHECK([whether frexpl() can be used without linking with libm], 103 [gl_cv_func_frexpl_no_libm], 104 [ 105 AC_LINK_IFELSE( 106 [AC_LANG_PROGRAM( 107 [[#include <math.h> 108 long double x;]], 109 [[int e; return frexpl (x, &e) > 0;]])], 110 [gl_cv_func_frexpl_no_libm=yes], 111 [gl_cv_func_frexpl_no_libm=no]) 112 ]) 113 ]) 114 115 dnl Test whether frexpl() works on finite numbers (this fails on 116 dnl Mac OS X 10.4/PowerPC, on AIX 5.1, and on BeOS), on denormalized numbers 117 dnl (this fails on Mac OS X 10.5/i386), and also on infinite numbers (this 118 dnl fails e.g. on IRIX 6.5 and mingw). 119 AC_DEFUN([gl_FUNC_FREXPL_WORKS], 120 [ 121 AC_REQUIRE([AC_PROG_CC]) 122 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 123 AC_CACHE_CHECK([whether frexpl works], [gl_cv_func_frexpl_works], 124 [ 125 AC_RUN_IFELSE( 126 [AC_LANG_SOURCE([[ 127 #include <float.h> 128 #include <math.h> 129 /* Override the values of <float.h>, like done in float.in.h. */ 130 #if defined __i386__ && (defined __BEOS__ || defined __OpenBSD__) 131 # undef LDBL_MIN_EXP 132 # define LDBL_MIN_EXP (-16381) 133 #endif 134 #if defined __i386__ && defined __FreeBSD__ 135 # undef LDBL_MIN_EXP 136 # define LDBL_MIN_EXP (-16381) 137 #endif 138 #if (defined _ARCH_PPC || defined _POWER) && defined _AIX && (LDBL_MANT_DIG == 106) && defined __GNUC__ 139 # undef LDBL_MIN_EXP 140 # define LDBL_MIN_EXP DBL_MIN_EXP 141 #endif 142 #if defined __sgi && (LDBL_MANT_DIG >= 106) 143 # if defined __GNUC__ 144 # undef LDBL_MIN_EXP 145 # define LDBL_MIN_EXP DBL_MIN_EXP 146 # endif 147 #endif 148 extern 149 #ifdef __cplusplus 150 "C" 151 #endif 152 long double frexpl (long double, int *); 153 int main() 154 { 155 int result = 0; 156 volatile long double x; 157 /* Test on finite numbers that fails on AIX 5.1. */ 158 x = 16.0L; 159 { 160 int exp = -9999; 161 frexpl (x, &exp); 162 if (exp != 5) 163 result |= 1; 164 } 165 /* Test on finite numbers that fails on Mac OS X 10.4, because its frexpl 166 function returns an invalid (incorrectly normalized) value: it returns 167 y = { 0x3fe028f5, 0xc28f5c28, 0x3c9eb851, 0xeb851eb8 } 168 but the correct result is 169 0.505L = { 0x3fe028f5, 0xc28f5c29, 0xbc547ae1, 0x47ae1480 } */ 170 x = 1.01L; 171 { 172 int exp = -9999; 173 long double y = frexpl (x, &exp); 174 if (!(exp == 1 && y == 0.505L)) 175 result |= 2; 176 } 177 /* Test on large finite numbers. This fails on BeOS at i = 16322, while 178 LDBL_MAX_EXP = 16384. 179 In the loop end test, we test x against Infinity, rather than comparing 180 i with LDBL_MAX_EXP, because BeOS <float.h> has a wrong LDBL_MAX_EXP. */ 181 { 182 int i; 183 for (i = 1, x = 1.0L; x != x + x; i++, x *= 2.0L) 184 { 185 int exp = -9999; 186 frexpl (x, &exp); 187 if (exp != i) 188 { 189 result |= 4; 190 break; 191 } 192 } 193 } 194 /* Test on denormalized numbers. */ 195 { 196 int i; 197 for (i = 1, x = 1.0L; i >= LDBL_MIN_EXP; i--, x *= 0.5L) 198 ; 199 if (x > 0.0L) 200 { 201 int exp; 202 long double y = frexpl (x, &exp); 203 /* On machines with IEEE854 arithmetic: x = 1.68105e-4932, 204 exp = -16382, y = 0.5. On Mac OS X 10.5: exp = -16384, y = 0.5. */ 205 if (exp != LDBL_MIN_EXP - 1) 206 result |= 8; 207 } 208 } 209 /* Test on infinite numbers. */ 210 x = 1.0L / 0.0L; 211 { 212 int exp; 213 long double y = frexpl (x, &exp); 214 if (y != x) 215 result |= 16; 216 } 217 return result; 218 }]])], 219 [gl_cv_func_frexpl_works=yes], 220 [gl_cv_func_frexpl_works=no], 221 [ 222 changequote(,)dnl 223 case "$host_os" in 224 aix | aix[3-6]* | beos* | darwin* | irix* | mingw* | pw*) 225 gl_cv_func_frexpl_works="guessing no";; 226 *) gl_cv_func_frexpl_works="guessing yes";; 227 esac 228 changequote([,])dnl 229 ]) 230 ]) 231 ]) 232
