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# isnanl.m4
# serial 26
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_ONCE([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 $gl_cv_func_isnanl_no_libm = yes || test -n "$ISNANL_LIBM"; then
saved_LIBS="$LIBS"
LIBS="$LIBS $ISNANL_LIBM"
gl_FUNC_ISNANL_WORKS
LIBS="$saved_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 $gl_func_isnanl_no_libm = yes; then
AC_DEFINE([HAVE_ISNANL_IN_LIBC], [1],
[Define if the isnan(long double) function is available in libc.])
fi
])
dnl Prerequisites of replacement isnanl definition. It does not need -lm.
AC_DEFUN([gl_PREREQ_ISNANL],
[
gl_LONG_DOUBLE_EXPONENT_LOCATION
AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
])
dnl Test whether isnanl() can be used without libm.
AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM],
[
AC_CACHE_CHECK([whether isnan(long double) can be used without linking with libm],
[gl_cv_func_isnanl_no_libm],
[
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <math.h>
#if (__GNUC__ >= 4) || (__clang_major__ >= 4)
# undef isnanl
# define isnanl(x) __builtin_isnan ((long double)(x))
#elif defined isnan
# undef isnanl
# define isnanl(x) isnan ((long double)(x))
#endif
long double x;]],
[[return isnanl (x);]])],
[gl_cv_func_isnanl_no_libm=yes],
[gl_cv_func_isnanl_no_libm=no])
])
])
dnl Test whether isnanl() can be used with libm.
AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM],
[
AC_CACHE_CHECK([whether isnan(long double) can be used with libm],
[gl_cv_func_isnanl_in_libm],
[
saved_LIBS="$LIBS"
LIBS="$LIBS -lm"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <math.h>
#if (__GNUC__ >= 4) || (__clang_major__ >= 4)
# undef isnanl
# define isnanl(x) __builtin_isnan ((long double)(x))
#elif defined isnan
# undef isnanl
# define isnanl(x) isnan ((long double)(x))
#endif
long double x;]],
[[return isnanl (x);]])],
[gl_cv_func_isnanl_in_libm=yes],
[gl_cv_func_isnanl_in_libm=no])
LIBS="$saved_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) || (__clang_major__ >= 4)
# undef isnanl
# define isnanl(x) __builtin_isnan ((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],
[case "$host_os" in
mingw* | windows*) # Guess yes on mingw, no on MSVC.
AC_EGREP_CPP([Known], [
#ifdef __MINGW32__
Known
#endif
],
[gl_cv_func_isnanl_works="guessing yes"],
[gl_cv_func_isnanl_works="guessing no"])
;;
*) gl_cv_func_isnanl_works="guessing yes" ;;
esac
])
])
])
|
