-# frexp.m4 serial 1
+# frexp.m4 serial 5
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,
else
AC_LIBOBJ([frexp])
fi
+ AC_SUBST([FREXP_LIBM])
])
-dnl Test whether frexp() works also on denormalized numbers.
-dnl This test fails e.g. on NetBSD.
+AC_DEFUN([gl_FUNC_FREXP_NO_LIBM],
+[
+ AC_REQUIRE([gl_MATH_H_DEFAULTS])
+ AC_CACHE_CHECK([whether frexp() can be used without linking with libm],
+ [gl_cv_func_frexp_no_libm],
+ [
+ AC_TRY_LINK([#include <math.h>
+ double x;],
+ [int e; return frexp (x, &e) > 0;],
+ [gl_cv_func_frexp_no_libm=yes],
+ [gl_cv_func_frexp_no_libm=no])
+ ])
+ if test $gl_cv_func_frexp_no_libm = yes; then
+ gl_FUNC_FREXP_WORKS
+ case "$gl_cv_func_frexp_works" in
+ *yes) gl_func_frexp_no_libm=yes ;;
+ *) gl_func_frexp_no_libm=no; REPLACE_FREXP=1 ;;
+ esac
+ else
+ gl_func_frexp_no_libm=no
+ dnl Set REPLACE_FREXP here because the system may have frexp in libm.
+ REPLACE_FREXP=1
+ fi
+ if test $gl_func_frexp_no_libm = yes; then
+ AC_DEFINE([HAVE_FREXP_IN_LIBC], 1,
+ [Define if the frexp() function is available in libc.])
+ else
+ AC_LIBOBJ([frexp])
+ fi
+])
+
+dnl Test whether frexp() works also on denormalized numbers (this fails e.g. on
+dnl NetBSD 3.0) and on infinite numbers (this fails e.g. on IRIX 6.5 and mingw).
AC_DEFUN([gl_FUNC_FREXP_WORKS],
[
AC_REQUIRE([AC_PROG_CC])
{
int i;
volatile double x;
+ /* Test on denormalized numbers. */
for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
;
if (x > 0.0)
if (y != 0.5)
return 1;
}
+ /* Test on infinite numbers. */
+ x = 1.0 / 0.0;
+ {
+ int exp;
+ double y = frexp (x, &exp);
+ if (y != x)
+ return 1;
+ }
return 0;
}], [gl_cv_func_frexp_works=yes], [gl_cv_func_frexp_works=no],
[case "$host_os" in
- netbsd*) gl_cv_func_frexp_works="guessing no";;
- *) gl_cv_func_frexp_works="guessing yes";;
+ netbsd* | irix* | mingw*) gl_cv_func_frexp_works="guessing no";;
+ *) gl_cv_func_frexp_works="guessing yes";;
esac
])
])