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-rw-r--r--gnulib_m4/ldexpl.m4135
1 files changed, 135 insertions, 0 deletions
diff --git a/gnulib_m4/ldexpl.m4 b/gnulib_m4/ldexpl.m4
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+++ b/gnulib_m4/ldexpl.m4
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+# ldexpl.m4 serial 17
+dnl Copyright (C) 2007-2023 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_LDEXPL],
+[
+ AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
+ AC_REQUIRE([gl_FUNC_ISNANL]) dnl for ISNANL_LIBM
+
+ dnl Persuade glibc <math.h> to declare ldexpl().
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+ dnl Check whether it's declared.
+ dnl Mac OS X 10.3 has ldexpl() in libc but doesn't declare it in <math.h>.
+ AC_CHECK_DECL([ldexpl], , [HAVE_DECL_LDEXPL=0], [[#include <math.h>]])
+
+ LDEXPL_LIBM=
+ if test $HAVE_DECL_LDEXPL = 1; then
+ gl_CHECK_LDEXPL_NO_LIBM
+ if test $gl_cv_func_ldexpl_no_libm = no; then
+ AC_CACHE_CHECK([whether ldexpl() can be used with libm],
+ [gl_cv_func_ldexpl_in_libm],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS -lm"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ long double x;]],
+ [[return ldexpl (x, -1) > 0;]])],
+ [gl_cv_func_ldexpl_in_libm=yes],
+ [gl_cv_func_ldexpl_in_libm=no])
+ LIBS="$save_LIBS"
+ ])
+ if test $gl_cv_func_ldexpl_in_libm = yes; then
+ LDEXPL_LIBM=-lm
+ fi
+ fi
+ if test $gl_cv_func_ldexpl_no_libm = yes \
+ || test $gl_cv_func_ldexpl_in_libm = yes; then
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $LDEXPL_LIBM"
+ gl_FUNC_LDEXPL_WORKS
+ LIBS="$save_LIBS"
+ case "$gl_cv_func_ldexpl_works" in
+ *yes) gl_func_ldexpl=yes ;;
+ *) gl_func_ldexpl=no; REPLACE_LDEXPL=1 ;;
+ esac
+ else
+ gl_func_ldexpl=no
+ fi
+ if test $gl_func_ldexpl = yes; then
+ AC_DEFINE([HAVE_LDEXPL], [1],
+ [Define if the ldexpl() function is available.])
+ fi
+ fi
+ if test $HAVE_DECL_LDEXPL = 0 || test $gl_func_ldexpl = no; then
+ dnl Find libraries needed to link lib/ldexpl.c.
+ if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
+ AC_REQUIRE([gl_FUNC_LDEXP])
+ LDEXPL_LIBM="$LDEXP_LIBM"
+ else
+ LDEXPL_LIBM="$ISNANL_LIBM"
+ fi
+ fi
+ AC_SUBST([LDEXPL_LIBM])
+])
+
+dnl Test whether ldexpl() can be used without linking with libm.
+dnl Set gl_cv_func_ldexpl_no_libm to 'yes' or 'no' accordingly.
+AC_DEFUN([gl_CHECK_LDEXPL_NO_LIBM],
+[
+ AC_CACHE_CHECK([whether ldexpl() can be used without linking with libm],
+ [gl_cv_func_ldexpl_no_libm],
+ [
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <math.h>
+ long double x;]],
+ [[return ldexpl (x, -1) > 0;]])],
+ [gl_cv_func_ldexpl_no_libm=yes],
+ [gl_cv_func_ldexpl_no_libm=no])
+ ])
+])
+
+dnl Test whether ldexpl() works on finite numbers (this fails on AIX 5.1
+dnl and Mac OS X 10.4/PowerPC).
+AC_DEFUN([gl_FUNC_LDEXPL_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether ldexpl works], [gl_cv_func_ldexpl_works],
+ [
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double ldexpl (long double, int);
+int main()
+{
+ int result = 0;
+ {
+ volatile long double x = 1.0;
+ volatile long double y = ldexpl (x, -1);
+ if (y != 0.5L)
+ result |= 1;
+ }
+ {
+ volatile long double x = 1.73205L;
+ volatile long double y = ldexpl (x, 0);
+ if (y != x)
+ result |= 2;
+ }
+ return result;
+}]])],
+ [gl_cv_func_ldexpl_works=yes],
+ [gl_cv_func_ldexpl_works=no],
+ [
+changequote(,)dnl
+ case "$host_os" in
+ aix | aix[3-6]*) gl_cv_func_ldexpl_works="guessing no" ;;
+ # Guess yes on native Windows.
+ mingw*) gl_cv_func_ldexpl_works="guessing yes" ;;
+ *) gl_cv_func_ldexpl_works="guessing yes" ;;
+ esac
+changequote([,])dnl
+ ])
+ ])
+])