1# isnanl.m4 serial 12 2dnl Copyright (C) 2007-2010 Free Software Foundation, Inc. 3dnl This file is free software; the Free Software Foundation 4dnl gives unlimited permission to copy and/or distribute it, 5dnl with or without modifications, as long as this notice is preserved. 6 7AC_DEFUN([gl_FUNC_ISNANL], 8[ 9 AC_REQUIRE([gl_MATH_H_DEFAULTS]) 10 ISNANL_LIBM= 11 gl_HAVE_ISNANL_NO_LIBM 12 if test $gl_cv_func_isnanl_no_libm = no; then 13 gl_HAVE_ISNANL_IN_LIBM 14 if test $gl_cv_func_isnanl_in_libm = yes; then 15 ISNANL_LIBM=-lm 16 fi 17 fi 18 if test $gl_cv_func_isnanl_no_libm = yes \ 19 || test $gl_cv_func_isnanl_in_libm = yes; then 20 save_LIBS="$LIBS" 21 LIBS="$LIBS $ISNANL_LIBM" 22 gl_FUNC_ISNANL_WORKS 23 LIBS="$save_LIBS" 24 case "$gl_cv_func_isnanl_works" in 25 *yes) gl_func_isnanl=yes ;; 26 *) gl_func_isnanl=no; ISNANL_LIBM= ;; 27 esac 28 else 29 gl_func_isnanl=no 30 fi 31 if test $gl_func_isnanl != yes; then 32 HAVE_ISNANL=0 33 gl_BUILD_ISNANL 34 fi 35 AC_SUBST([ISNANL_LIBM]) 36]) 37 38AC_DEFUN([gl_FUNC_ISNANL_NO_LIBM], 39[ 40 gl_HAVE_ISNANL_NO_LIBM 41 gl_func_isnanl_no_libm=$gl_cv_func_isnanl_no_libm 42 if test $gl_func_isnanl_no_libm = yes; then 43 gl_FUNC_ISNANL_WORKS 44 case "$gl_cv_func_isnanl_works" in 45 *yes) ;; 46 *) gl_func_isnanl_no_libm=no ;; 47 esac 48 fi 49 if test $gl_func_isnanl_no_libm = yes; then 50 AC_DEFINE([HAVE_ISNANL_IN_LIBC], [1], 51 [Define if the isnan(long double) function is available in libc.]) 52 else 53 gl_BUILD_ISNANL 54 fi 55]) 56 57dnl Pull in replacement isnanl definition. It does not need -lm. 58AC_DEFUN([gl_BUILD_ISNANL], 59[ 60 AC_LIBOBJ([isnanl]) 61 gl_LONG_DOUBLE_EXPONENT_LOCATION 62]) 63 64dnl Test whether isnanl() can be used without libm. 65AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM], 66[ 67 AC_CACHE_CHECK([whether isnan(long double) can be used without linking with libm], 68 [gl_cv_func_isnanl_no_libm], 69 [ 70 AC_TRY_LINK([#include <math.h> 71 #if __GNUC__ >= 4 72 # undef isnanl 73 # define isnanl(x) __builtin_isnanl ((long double)(x)) 74 #elif defined isnan 75 # undef isnanl 76 # define isnanl(x) isnan ((long double)(x)) 77 #endif 78 long double x;], 79 [return isnanl (x);], 80 [gl_cv_func_isnanl_no_libm=yes], 81 [gl_cv_func_isnanl_no_libm=no]) 82 ]) 83]) 84 85dnl Test whether isnanl() can be used with libm. 86AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM], 87[ 88 AC_CACHE_CHECK([whether isnan(long double) can be used with libm], 89 [gl_cv_func_isnanl_in_libm], 90 [ 91 save_LIBS="$LIBS" 92 LIBS="$LIBS -lm" 93 AC_TRY_LINK([#include <math.h> 94 #if __GNUC__ >= 4 95 # undef isnanl 96 # define isnanl(x) __builtin_isnanl ((long double)(x)) 97 #elif defined isnan 98 # undef isnanl 99 # define isnanl(x) isnan ((long double)(x)) 100 #endif 101 long double x;], 102 [return isnanl (x);], 103 [gl_cv_func_isnanl_in_libm=yes], 104 [gl_cv_func_isnanl_in_libm=no]) 105 LIBS="$save_LIBS" 106 ]) 107]) 108 109dnl Test whether isnanl() recognizes all numbers which are neither finite nor 110dnl infinite. This test fails e.g. on NetBSD/i386 and on glibc/ia64. 111dnl Also, the GCC >= 4.0 built-in __builtin_isnanl does not pass the tests 112dnl - for pseudo-denormals on i686 and x86_64, 113dnl - for pseudo-zeroes, unnormalized numbers, and pseudo-denormals on ia64. 114AC_DEFUN([gl_FUNC_ISNANL_WORKS], 115[ 116 AC_REQUIRE([AC_PROG_CC]) 117 AC_REQUIRE([gl_BIGENDIAN]) 118 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 119 AC_CACHE_CHECK([whether isnanl works], [gl_cv_func_isnanl_works], 120 [ 121 AC_TRY_RUN([ 122#include <float.h> 123#include <limits.h> 124#include <math.h> 125#if __GNUC__ >= 4 126# undef isnanl 127# define isnanl(x) __builtin_isnanl ((long double)(x)) 128#elif defined isnan 129# undef isnanl 130# define isnanl(x) isnan ((long double)(x)) 131#endif 132#define NWORDS \ 133 ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) 134typedef union { unsigned int word[NWORDS]; long double value; } 135 memory_long_double; 136/* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the 137 runtime type conversion. */ 138#ifdef __sgi 139static long double NaNl () 140{ 141 double zero = 0.0; 142 return zero / zero; 143} 144#else 145# define NaNl() (0.0L / 0.0L) 146#endif 147int main () 148{ 149 memory_long_double m; 150 unsigned int i; 151 152 if (!isnanl (NaNl ())) 153 return 1; 154 155 /* The isnanl function should be immune against changes in the sign bit and 156 in the mantissa bits. The xor operation twiddles a bit that can only be 157 a sign bit or a mantissa bit (since the exponent never extends to 158 bit 31). */ 159 m.value = NaNl (); 160 m.word[NWORDS / 2] ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1); 161 for (i = 0; i < NWORDS; i++) 162 m.word[i] |= 1; 163 if (!isnanl (m.value)) 164 return 1; 165 166#if ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_)) 167/* Representation of an 80-bit 'long double' as an initializer for a sequence 168 of 'unsigned int' words. */ 169# ifdef WORDS_BIGENDIAN 170# define LDBL80_WORDS(exponent,manthi,mantlo) \ 171 { ((unsigned int) (exponent) << 16) | ((unsigned int) (manthi) >> 16), \ 172 ((unsigned int) (manthi) << 16) | (unsigned int) (mantlo) >> 16), \ 173 (unsigned int) (mantlo) << 16 \ 174 } 175# else 176# define LDBL80_WORDS(exponent,manthi,mantlo) \ 177 { mantlo, manthi, exponent } 178# endif 179 { /* Quiet NaN. */ 180 static memory_long_double x = 181 { LDBL80_WORDS (0xFFFF, 0xC3333333, 0x00000000) }; 182 if (!isnanl (x.value)) 183 return 1; 184 } 185 { 186 /* Signalling NaN. */ 187 static memory_long_double x = 188 { LDBL80_WORDS (0xFFFF, 0x83333333, 0x00000000) }; 189 if (!isnanl (x.value)) 190 return 1; 191 } 192 /* The isnanl function should recognize Pseudo-NaNs, Pseudo-Infinities, 193 Pseudo-Zeroes, Unnormalized Numbers, and Pseudo-Denormals, as defined in 194 Intel IA-64 Architecture Software Developer's Manual, Volume 1: 195 Application Architecture. 196 Table 5-2 "Floating-Point Register Encodings" 197 Figure 5-6 "Memory to Floating-Point Register Data Translation" 198 */ 199 { /* Pseudo-NaN. */ 200 static memory_long_double x = 201 { LDBL80_WORDS (0xFFFF, 0x40000001, 0x00000000) }; 202 if (!isnanl (x.value)) 203 return 1; 204 } 205 { /* Pseudo-Infinity. */ 206 static memory_long_double x = 207 { LDBL80_WORDS (0xFFFF, 0x00000000, 0x00000000) }; 208 if (!isnanl (x.value)) 209 return 1; 210 } 211 { /* Pseudo-Zero. */ 212 static memory_long_double x = 213 { LDBL80_WORDS (0x4004, 0x00000000, 0x00000000) }; 214 if (!isnanl (x.value)) 215 return 1; 216 } 217 { /* Unnormalized number. */ 218 static memory_long_double x = 219 { LDBL80_WORDS (0x4000, 0x63333333, 0x00000000) }; 220 if (!isnanl (x.value)) 221 return 1; 222 } 223 { /* Pseudo-Denormal. */ 224 static memory_long_double x = 225 { LDBL80_WORDS (0x0000, 0x83333333, 0x00000000) }; 226 if (!isnanl (x.value)) 227 return 1; 228 } 229#endif 230 231 return 0; 232}], [gl_cv_func_isnanl_works=yes], [gl_cv_func_isnanl_works=no], 233 [case "$host_cpu" in 234 # Guess no on ia64, x86_64, i386. 235 ia64 | x86_64 | i*86) gl_cv_func_isnanl_works="guessing no";; 236 *) 237 case "$host_os" in 238 netbsd*) gl_cv_func_isnanl_works="guessing no";; 239 *) gl_cv_func_isnanl_works="guessing yes";; 240 esac 241 ;; 242 esac 243 ]) 244 ]) 245]) 246