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Diffstat (limited to 'm4/isnanl.m4')
| -rw-r--r-- | m4/isnanl.m4 | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/m4/isnanl.m4 b/m4/isnanl.m4 new file mode 100644 index 0000000..9766e47 --- /dev/null +++ b/m4/isnanl.m4 @@ -0,0 +1,236 @@ +# isnanl.m4 serial 19 +dnl Copyright (C) 2007-2016 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_ISNANL], +[ + AC_REQUIRE([gl_MATH_H_DEFAULTS]) + ISNANL_LIBM= + gl_HAVE_ISNANL_NO_LIBM + if test $gl_cv_func_isnanl_no_libm = no; then + gl_HAVE_ISNANL_IN_LIBM + if test $gl_cv_func_isnanl_in_libm = yes; then + ISNANL_LIBM=-lm + fi + fi + dnl The variable gl_func_isnanl set here is used by isnan.m4. + if test $gl_cv_func_isnanl_no_libm = yes \ + || test $gl_cv_func_isnanl_in_libm = yes; then + save_LIBS="$LIBS" + LIBS="$LIBS $ISNANL_LIBM" + gl_FUNC_ISNANL_WORKS + LIBS="$save_LIBS" + case "$gl_cv_func_isnanl_works" in + *yes) gl_func_isnanl=yes ;; + *) gl_func_isnanl=no; ISNANL_LIBM= ;; + esac + else + gl_func_isnanl=no + fi + if test $gl_func_isnanl != yes; then + HAVE_ISNANL=0 + fi + AC_SUBST([ISNANL_LIBM]) +]) + +AC_DEFUN([gl_FUNC_ISNANL_NO_LIBM], +[ + gl_HAVE_ISNANL_NO_LIBM + gl_func_isnanl_no_libm=$gl_cv_func_isnanl_no_libm + if test $gl_func_isnanl_no_libm = yes; then + gl_FUNC_ISNANL_WORKS + case "$gl_cv_func_isnanl_works" in + *yes) ;; + *) gl_func_isnanl_no_libm=no ;; + esac + fi + if test $gl_func_isnanl_no_libm = yes; then + AC_DEFINE([HAVE_ISNANL_IN_LIBC], [1], + [Define if the isnan(long double) function is available in libc.]) + fi +]) + +dnl Prerequisites of replacement isnanl definition. It does not need -lm. +AC_DEFUN([gl_PREREQ_ISNANL], +[ + gl_LONG_DOUBLE_EXPONENT_LOCATION + AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) +]) + +dnl Test whether isnanl() can be used without libm. +AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM], +[ + AC_CACHE_CHECK([whether isnan(long double) can be used without linking with libm], + [gl_cv_func_isnanl_no_libm], + [ + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + #if __GNUC__ >= 4 + # undef isnanl + # define isnanl(x) __builtin_isnanl ((long double)(x)) + #elif defined isnan + # undef isnanl + # define isnanl(x) isnan ((long double)(x)) + #endif + long double x;]], + [[return isnanl (x);]])], + [gl_cv_func_isnanl_no_libm=yes], + [gl_cv_func_isnanl_no_libm=no]) + ]) +]) + +dnl Test whether isnanl() can be used with libm. +AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM], +[ + AC_CACHE_CHECK([whether isnan(long double) can be used with libm], + [gl_cv_func_isnanl_in_libm], + [ + save_LIBS="$LIBS" + LIBS="$LIBS -lm" + AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <math.h> + #if __GNUC__ >= 4 + # undef isnanl + # define isnanl(x) __builtin_isnanl ((long double)(x)) + #elif defined isnan + # undef isnanl + # define isnanl(x) isnan ((long double)(x)) + #endif + long double x;]], + [[return isnanl (x);]])], + [gl_cv_func_isnanl_in_libm=yes], + [gl_cv_func_isnanl_in_libm=no]) + LIBS="$save_LIBS" + ]) +]) + +dnl Test whether isnanl() recognizes all canonical numbers which are neither +dnl finite nor infinite. +AC_DEFUN([gl_FUNC_ISNANL_WORKS], +[ + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([gl_BIGENDIAN]) + AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + AC_CACHE_CHECK([whether isnanl works], [gl_cv_func_isnanl_works], + [ + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ +#include <float.h> +#include <limits.h> +#include <math.h> +#if __GNUC__ >= 4 +# undef isnanl +# define isnanl(x) __builtin_isnanl ((long double)(x)) +#elif defined isnan +# undef isnanl +# define isnanl(x) isnan ((long double)(x)) +#endif +#define NWORDS \ + ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int)) +typedef union { unsigned int word[NWORDS]; long double value; } + memory_long_double; +/* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the + runtime type conversion. */ +#ifdef __sgi +static long double NaNl () +{ + double zero = 0.0; + return zero / zero; +} +#else +# define NaNl() (0.0L / 0.0L) +#endif +int main () +{ + int result = 0; + + if (!isnanl (NaNl ())) + result |= 1; + + { + memory_long_double m; + unsigned int i; + + /* The isnanl function should be immune against changes in the sign bit and + in the mantissa bits. The xor operation twiddles a bit that can only be + a sign bit or a mantissa bit (since the exponent never extends to + bit 31). */ + m.value = NaNl (); + m.word[NWORDS / 2] ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1); + for (i = 0; i < NWORDS; i++) + m.word[i] |= 1; + if (!isnanl (m.value)) + result |= 1; + } + +#if ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_)) && !HAVE_SAME_LONG_DOUBLE_AS_DOUBLE +/* Representation of an 80-bit 'long double' as an initializer for a sequence + of 'unsigned int' words. */ +# ifdef WORDS_BIGENDIAN +# define LDBL80_WORDS(exponent,manthi,mantlo) \ + { ((unsigned int) (exponent) << 16) | ((unsigned int) (manthi) >> 16), \ + ((unsigned int) (manthi) << 16) | ((unsigned int) (mantlo) >> 16), \ + (unsigned int) (mantlo) << 16 \ + } +# else +# define LDBL80_WORDS(exponent,manthi,mantlo) \ + { mantlo, manthi, exponent } +# endif + { /* Quiet NaN. */ + static memory_long_double x = + { LDBL80_WORDS (0xFFFF, 0xC3333333, 0x00000000) }; + if (!isnanl (x.value)) + result |= 2; + } + { + /* Signalling NaN. */ + static memory_long_double x = + { LDBL80_WORDS (0xFFFF, 0x83333333, 0x00000000) }; + if (!isnanl (x.value)) + result |= 2; + } + /* isnanl should return something even for noncanonical values. */ + { /* Pseudo-NaN. */ + static memory_long_double x = + { LDBL80_WORDS (0xFFFF, 0x40000001, 0x00000000) }; + if (isnanl (x.value) && !isnanl (x.value)) + result |= 4; + } + { /* Pseudo-Infinity. */ + static memory_long_double x = + { LDBL80_WORDS (0xFFFF, 0x00000000, 0x00000000) }; + if (isnanl (x.value) && !isnanl (x.value)) + result |= 8; + } + { /* Pseudo-Zero. */ + static memory_long_double x = + { LDBL80_WORDS (0x4004, 0x00000000, 0x00000000) }; + if (isnanl (x.value) && !isnanl (x.value)) + result |= 16; + } + { /* Unnormalized number. */ + static memory_long_double x = + { LDBL80_WORDS (0x4000, 0x63333333, 0x00000000) }; + if (isnanl (x.value) && !isnanl (x.value)) + result |= 32; + } + { /* Pseudo-Denormal. */ + static memory_long_double x = + { LDBL80_WORDS (0x0000, 0x83333333, 0x00000000) }; + if (isnanl (x.value) && !isnanl (x.value)) + result |= 64; + } +#endif + + return result; +}]])], + [gl_cv_func_isnanl_works=yes], + [gl_cv_func_isnanl_works=no], + [gl_cv_func_isnanl_works="guessing yes"]) + ]) +]) |