blob: fc79f0b0c2612e8dc9f718dba75688c13ac053b0 [file] [log] [blame]
# isnand.m4 serial 12
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.
dnl Check how to get or define isnand().
AC_DEFUN([gl_FUNC_ISNAND],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
ISNAND_LIBM=
gl_HAVE_ISNAND_NO_LIBM
if test $gl_cv_func_isnand_no_libm = no; then
gl_HAVE_ISNAND_IN_LIBM
if test $gl_cv_func_isnand_in_libm = yes; then
ISNAND_LIBM=-lm
fi
fi
dnl The variable gl_func_isnand set here is used by isnan.m4.
if test $gl_cv_func_isnand_no_libm = yes \
|| test $gl_cv_func_isnand_in_libm = yes; then
gl_func_isnand=yes
else
gl_func_isnand=no
HAVE_ISNAND=0
fi
AC_SUBST([ISNAND_LIBM])
])
dnl Check how to get or define isnand() without linking with libm.
AC_DEFUN([gl_FUNC_ISNAND_NO_LIBM],
[
gl_HAVE_ISNAND_NO_LIBM
gl_func_isnand_no_libm=$gl_cv_func_isnand_no_libm
if test $gl_cv_func_isnand_no_libm = yes; then
AC_DEFINE([HAVE_ISNAND_IN_LIBC], [1],
[Define if the isnan(double) function is available in libc.])
fi
])
dnl Prerequisites of replacement isnand definition. It does not need -lm.
AC_DEFUN([gl_PREREQ_ISNAND],
[
AC_REQUIRE([gl_DOUBLE_EXPONENT_LOCATION])
])
dnl Test whether isnand() can be used with libm.
AC_DEFUN([gl_HAVE_ISNAND_IN_LIBM],
[
AC_CACHE_CHECK([whether isnan(double) can be used with libm],
[gl_cv_func_isnand_in_libm],
[
save_LIBS="$LIBS"
LIBS="$LIBS -lm"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <math.h>
#if (__GNUC__ >= 4) || (__clang_major__ >= 4)
# undef isnand
# define isnand(x) __builtin_isnan ((double)(x))
#elif defined isnan
# undef isnand
# define isnand(x) isnan ((double)(x))
#endif
double x;]],
[[return isnand (x);]])],
[gl_cv_func_isnand_in_libm=yes],
[gl_cv_func_isnand_in_libm=no])
LIBS="$save_LIBS"
])
])
AC_DEFUN([gl_HAVE_ISNAND_NO_LIBM],
[
AC_CACHE_CHECK([whether isnan(double) can be used without linking with libm],
[gl_cv_func_isnand_no_libm],
[
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <math.h>
#if (__GNUC__ >= 4) || (__clang_major__ >= 4)
# undef isnand
# define isnand(x) __builtin_isnan ((double)(x))
#else
# undef isnand
# define isnand(x) isnan ((double)(x))
#endif
double x;]],
[[return isnand (x);]])],
[gl_cv_func_isnand_no_libm=yes],
[gl_cv_func_isnand_no_libm=no])
])
])