Tag
Hash :
6cba4900
Author :
Date :
2007-06-16T22:54:40
Work around a buggy frexpl function on MacOS X 10.4/PowerPC.
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# frexpl.m4 serial 6
dnl Copyright (C) 2007 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_FREXPL],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
FREXPL_LIBM=
AC_CACHE_CHECK([whether frexpl() can be used without linking with libm],
[gl_cv_func_frexpl_no_libm],
[
AC_TRY_LINK([#include <math.h>
long double x;],
[int e; return frexpl (x, &e) > 0;],
[gl_cv_func_frexpl_no_libm=yes],
[gl_cv_func_frexpl_no_libm=no])
])
if test $gl_cv_func_frexpl_no_libm = no; then
AC_CACHE_CHECK([whether frexpl() can be used with libm],
[gl_cv_func_frexpl_in_libm],
[
save_LIBS="$LIBS"
LIBS="$LIBS -lm"
AC_TRY_LINK([#include <math.h>
long double x;],
[int e; return frexpl (x, &e) > 0;],
[gl_cv_func_frexpl_in_libm=yes],
[gl_cv_func_frexpl_in_libm=no])
LIBS="$save_LIBS"
])
if test $gl_cv_func_frexpl_in_libm = yes; then
FREXPL_LIBM=-lm
fi
fi
if test $gl_cv_func_frexpl_no_libm = yes \
|| test $gl_cv_func_frexpl_in_libm = yes; then
save_LIBS="$LIBS"
LIBS="$LIBS $FREXPL_LIBM"
gl_FUNC_FREXPL_WORKS
LIBS="$save_LIBS"
case "$gl_cv_func_frexpl_works" in
*yes) gl_func_frexpl=yes ;;
*) gl_func_frexpl=no; REPLACE_FREXPL=1; FREXPL_LIBM= ;;
esac
else
gl_func_frexpl=no
fi
if test $gl_func_frexpl = yes; then
AC_DEFINE([HAVE_FREXPL], 1,
[Define if the frexpl() function is available.])
dnl Also check whether it's declared.
dnl MacOS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>.
AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [#include <math.h>])
else
HAVE_DECL_FREXPL=0
AC_LIBOBJ([frexpl])
fi
AC_SUBST([FREXPL_LIBM])
])
AC_DEFUN([gl_FUNC_FREXPL_NO_LIBM],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_CACHE_CHECK([whether frexpl() can be used without linking with libm],
[gl_cv_func_frexpl_no_libm],
[
AC_TRY_LINK([#include <math.h>
long double x;],
[int e; return frexpl (x, &e) > 0;],
[gl_cv_func_frexpl_no_libm=yes],
[gl_cv_func_frexpl_no_libm=no])
])
if test $gl_cv_func_frexpl_no_libm = yes; then
gl_FUNC_FREXPL_WORKS
case "$gl_cv_func_frexpl_works" in
*yes) gl_func_frexpl_no_libm=yes ;;
*) gl_func_frexpl_no_libm=no; REPLACE_FREXPL=1 ;;
esac
else
gl_func_frexpl_no_libm=no
dnl Set REPLACE_FREXPL here because the system may have frexpl in libm.
REPLACE_FREXPL=1
fi
if test $gl_func_frexpl_no_libm = yes; then
AC_DEFINE([HAVE_FREXPL_IN_LIBC], 1,
[Define if the frexpl() function is available in libc.])
dnl Also check whether it's declared.
dnl MacOS X 10.3 has frexpl() in libc but doesn't declare it in <math.h>.
AC_CHECK_DECL([frexpl], , [HAVE_DECL_FREXPL=0], [#include <math.h>])
else
HAVE_DECL_FREXPL=0
AC_LIBOBJ([frexpl])
fi
])
dnl Test whether frexpl() works on finite numbers (this fails on
dnl MacOS X 10.4/PowerPC, on AIX 5.1, and on BeOS) and also on infinite numbers
dnl (this fails e.g. on IRIX 6.5 and mingw).
AC_DEFUN([gl_FUNC_FREXPL_WORKS],
[
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether frexpl works], [gl_cv_func_frexpl_works],
[
AC_TRY_RUN([
#include <math.h>
extern long double frexpl (long double, int *);
int main()
{
volatile long double x;
/* Test on finite numbers that fails on AIX 5.1. */
x = 16.0L;
{
int exp = -9999;
frexpl (x, &exp);
if (exp != 5)
return 1;
}
/* Test on finite numbers that fails on MacOS X 10.4, because its frexpl
function returns an invalid (incorrectly normalized) value: it returns
y = { 0x3fe028f5, 0xc28f5c28, 0x3c9eb851, 0xeb851eb8 }
but the correct result is
0.505L = { 0x3fe028f5, 0xc28f5c29, 0xbc547ae1, 0x47ae1480 } */
x = 1.01L;
{
int exp = -9999;
long double y = frexpl (x, &exp);
if (!(exp == 1 && y == 0.505L))
return 1;
}
/* Test on large finite numbers. This fails on BeOS at i = 16322, while
LDBL_MAX_EXP = 16384.
In the loop end test, we test x against Infinity, rather than comparing
i with LDBL_MAX_EXP, because BeOS <float.h> has a wrong LDBL_MAX_EXP. */
{
int i;
for (i = 1, x = 1.0L; x != x + x; i++, x *= 2.0L)
{
int exp = -9999;
frexpl (x, &exp);
if (exp != i)
return 1;
}
}
/* Test on infinite numbers. */
x = 1.0L / 0.0L;
{
int exp;
long double y = frexpl (x, &exp);
if (y != x)
return 1;
}
return 0;
}], [gl_cv_func_frexpl_works=yes], [gl_cv_func_frexpl_works=no],
[case "$host_os" in
aix* | beos* | darwin* | irix* | mingw* | pw*)
gl_cv_func_frexpl_works="guessing no";;
*) gl_cv_func_frexpl_works="guessing yes";;
esac
])
])
])