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Diffstat (limited to 'gnulib-m4/signbit.m4')
-rw-r--r--gnulib-m4/signbit.m4188
1 files changed, 102 insertions, 86 deletions
diff --git a/gnulib-m4/signbit.m4 b/gnulib-m4/signbit.m4
index 9e7884d..8a4114d 100644
--- a/gnulib-m4/signbit.m4
+++ b/gnulib-m4/signbit.m4
@@ -1,5 +1,5 @@
-# signbit.m4 serial 16
-dnl Copyright (C) 2007-2018 Free Software Foundation, Inc.
+# signbit.m4 serial 20
+dnl Copyright (C) 2007-2022 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.
@@ -7,7 +7,7 @@ dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_SIGNBIT],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
- AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_REQUIRE([AC_CANONICAL_HOST])
AC_CACHE_CHECK([for signbit macro], [gl_cv_func_signbit],
[
AC_RUN_IFELSE(
@@ -31,22 +31,25 @@ AC_DEFUN([gl_SIGNBIT],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu* | gnu*) gl_cv_func_signbit="guessing yes" ;;
+ # Guess yes on musl systems.
+ *-musl*) gl_cv_func_signbit="guessing yes" ;;
# Guess yes on native Windows.
mingw*) gl_cv_func_signbit="guessing yes" ;;
- # If we don't know, assume the worst.
- *) gl_cv_func_signbit="guessing no" ;;
+ # If we don't know, obey --enable-cross-guesses.
+ *) gl_cv_func_signbit="$gl_cross_guess_normal" ;;
esac
])
])
- dnl GCC 4.0 and newer provides three built-ins for signbit.
+ dnl GCC >= 4.0 and clang provide three built-ins for signbit.
dnl They can be used without warnings, also in C++, regardless of <math.h>.
dnl But they may expand to calls to functions, which may or may not be in
dnl libc.
- AC_CACHE_CHECK([for signbit compiler built-ins], [gl_cv_func_signbit_gcc],
+ AC_CACHE_CHECK([for signbit compiler built-ins],
+ [gl_cv_func_signbit_builtins],
[
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
-#if __GNUC__ >= 4
+#if (__GNUC__ >= 4) || (__clang_major__ >= 4)
# define signbit(x) \
(sizeof (x) == sizeof (long double) ? __builtin_signbitl (x) : \
sizeof (x) == sizeof (double) ? __builtin_signbit (x) : \
@@ -57,28 +60,30 @@ AC_DEFUN([gl_SIGNBIT],
#include <string.h>
]gl_SIGNBIT_TEST_PROGRAM
])],
- [gl_cv_func_signbit_gcc=yes],
- [gl_cv_func_signbit_gcc=no],
+ [gl_cv_func_signbit_builtins=yes],
+ [gl_cv_func_signbit_builtins=no],
[case "$host_os" in
# Guess yes on glibc systems.
- *-gnu* | gnu*) gl_cv_func_signbit_gcc="guessing yes" ;;
+ *-gnu* | gnu*) gl_cv_func_signbit_builtins="guessing yes" ;;
+ # Guess yes on musl systems.
+ *-musl*) gl_cv_func_signbit_builtins="guessing yes" ;;
# Guess yes on mingw, no on MSVC.
mingw*) if test -n "$GCC"; then
- gl_cv_func_signbit_gcc="guessing yes"
+ gl_cv_func_signbit_builtins="guessing yes"
else
- gl_cv_func_signbit_gcc="guessing no"
+ gl_cv_func_signbit_builtins="guessing no"
fi
;;
- # If we don't know, assume the worst.
- *) gl_cv_func_signbit_gcc="guessing no" ;;
+ # If we don't know, obey --enable-cross-guesses.
+ *) gl_cv_func_signbit_builtins="$gl_cross_guess_normal" ;;
esac
])
])
dnl Use the compiler built-ins whenever possible, because they are more
dnl efficient than the system library functions (if they exist).
- case "$gl_cv_func_signbit_gcc" in
+ case "$gl_cv_func_signbit_builtins" in
*yes)
- REPLACE_SIGNBIT_USING_GCC=1
+ REPLACE_SIGNBIT_USING_BUILTINS=1
;;
*)
case "$gl_cv_func_signbit" in
@@ -86,79 +91,90 @@ AC_DEFUN([gl_SIGNBIT],
*)
dnl REPLACE_SIGNBIT=1 makes sure the signbit[fdl] functions get built.
REPLACE_SIGNBIT=1
- gl_FLOAT_SIGN_LOCATION
- gl_DOUBLE_SIGN_LOCATION
- gl_LONG_DOUBLE_SIGN_LOCATION
- if test "$gl_cv_cc_float_signbit" = unknown; then
- dnl Test whether copysignf() is declared.
- AC_CHECK_DECLS([copysignf], , , [[#include <math.h>]])
- if test "$ac_cv_have_decl_copysignf" = yes; then
- dnl Test whether copysignf() can be used without libm.
- AC_CACHE_CHECK([whether copysignf can be used without linking with libm],
- [gl_cv_func_copysignf_no_libm],
- [
- AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [[#include <math.h>
- float x, y;]],
- [[return copysignf (x, y) < 0;]])],
- [gl_cv_func_copysignf_no_libm=yes],
- [gl_cv_func_copysignf_no_libm=no])
- ])
- if test $gl_cv_func_copysignf_no_libm = yes; then
- AC_DEFINE([HAVE_COPYSIGNF_IN_LIBC], [1],
- [Define if the copysignf function is declared in <math.h> and available in libc.])
- fi
- fi
- fi
- if test "$gl_cv_cc_double_signbit" = unknown; then
- dnl Test whether copysign() is declared.
- AC_CHECK_DECLS([copysign], , , [[#include <math.h>]])
- if test "$ac_cv_have_decl_copysign" = yes; then
- dnl Test whether copysign() can be used without libm.
- AC_CACHE_CHECK([whether copysign can be used without linking with libm],
- [gl_cv_func_copysign_no_libm],
- [
- AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [[#include <math.h>
- double x, y;]],
- [[return copysign (x, y) < 0;]])],
- [gl_cv_func_copysign_no_libm=yes],
- [gl_cv_func_copysign_no_libm=no])
- ])
- if test $gl_cv_func_copysign_no_libm = yes; then
- AC_DEFINE([HAVE_COPYSIGN_IN_LIBC], [1],
- [Define if the copysign function is declared in <math.h> and available in libc.])
- fi
- fi
- fi
- if test "$gl_cv_cc_long_double_signbit" = unknown; then
- dnl Test whether copysignl() is declared.
- AC_CHECK_DECLS([copysignl], , , [[#include <math.h>]])
- if test "$ac_cv_have_decl_copysignl" = yes; then
- dnl Test whether copysignl() can be used without libm.
- AC_CACHE_CHECK([whether copysignl can be used without linking with libm],
- [gl_cv_func_copysignl_no_libm],
- [
- AC_LINK_IFELSE(
- [AC_LANG_PROGRAM(
- [[#include <math.h>
- long double x, y;]],
- [[return copysignl (x, y) < 0;]])],
- [gl_cv_func_copysignl_no_libm=yes],
- [gl_cv_func_copysignl_no_libm=no])
- ])
- if test $gl_cv_func_copysignl_no_libm = yes; then
- AC_DEFINE([HAVE_COPYSIGNL_IN_LIBC], [1],
- [Define if the copysignl function is declared in <math.h> and available in libc.])
- fi
- fi
- fi
;;
esac
;;
esac
+ dnl On Solaris 10, with CC in C++ mode, signbit is not available although
+ dnl is with cc in C mode. This cannot be worked around by defining
+ dnl _XOPEN_SOURCE=600, because the latter does not work in C++ mode on
+ dnl Solaris 11.0. Therefore use the replacement functions on Solaris.
+ case "$host_os" in
+ solaris*)
+ REPLACE_SIGNBIT=1
+ ;;
+ esac
+ if test $REPLACE_SIGNBIT = 1; then
+ gl_FLOAT_SIGN_LOCATION
+ gl_DOUBLE_SIGN_LOCATION
+ gl_LONG_DOUBLE_SIGN_LOCATION
+ if test "$gl_cv_cc_float_signbit" = unknown; then
+ dnl Test whether copysignf() is declared.
+ AC_CHECK_DECLS([copysignf], , , [[#include <math.h>]])
+ if test "$ac_cv_have_decl_copysignf" = yes; then
+ dnl Test whether copysignf() can be used without libm.
+ AC_CACHE_CHECK([whether copysignf can be used without linking with libm],
+ [gl_cv_func_copysignf_no_libm],
+ [
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ float x, y;]],
+ [[return copysignf (x, y) < 0;]])],
+ [gl_cv_func_copysignf_no_libm=yes],
+ [gl_cv_func_copysignf_no_libm=no])
+ ])
+ if test $gl_cv_func_copysignf_no_libm = yes; then
+ AC_DEFINE([HAVE_COPYSIGNF_IN_LIBC], [1],
+ [Define if the copysignf function is declared in <math.h> and available in libc.])
+ fi
+ fi
+ fi
+ if test "$gl_cv_cc_double_signbit" = unknown; then
+ dnl Test whether copysign() is declared.
+ AC_CHECK_DECLS([copysign], , , [[#include <math.h>]])
+ if test "$ac_cv_have_decl_copysign" = yes; then
+ dnl Test whether copysign() can be used without libm.
+ AC_CACHE_CHECK([whether copysign can be used without linking with libm],
+ [gl_cv_func_copysign_no_libm],
+ [
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ double x, y;]],
+ [[return copysign (x, y) < 0;]])],
+ [gl_cv_func_copysign_no_libm=yes],
+ [gl_cv_func_copysign_no_libm=no])
+ ])
+ if test $gl_cv_func_copysign_no_libm = yes; then
+ AC_DEFINE([HAVE_COPYSIGN_IN_LIBC], [1],
+ [Define if the copysign function is declared in <math.h> and available in libc.])
+ fi
+ fi
+ fi
+ if test "$gl_cv_cc_long_double_signbit" = unknown; then
+ dnl Test whether copysignl() is declared.
+ AC_CHECK_DECLS([copysignl], , , [[#include <math.h>]])
+ if test "$ac_cv_have_decl_copysignl" = yes; then
+ dnl Test whether copysignl() can be used without libm.
+ AC_CACHE_CHECK([whether copysignl can be used without linking with libm],
+ [gl_cv_func_copysignl_no_libm],
+ [
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ long double x, y;]],
+ [[return copysignl (x, y) < 0;]])],
+ [gl_cv_func_copysignl_no_libm=yes],
+ [gl_cv_func_copysignl_no_libm=no])
+ ])
+ if test $gl_cv_func_copysignl_no_libm = yes; then
+ AC_DEFINE([HAVE_COPYSIGNL_IN_LIBC], [1],
+ [Define if the copysignl function is declared in <math.h> and available in libc.])
+ fi
+ fi
+ fi
+ fi
])
AC_DEFUN([gl_SIGNBIT_TEST_PROGRAM], [[