-# isnanf.m4 serial 1
+# isnanf.m4 serial 4
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,
[
gl_HAVE_ISNANF_NO_LIBM
if test $gl_cv_func_isnanf_no_libm = yes; then
+ gl_ISNANF_WORKS
+ fi
+ if test $gl_cv_func_isnanf_no_libm = yes \
+ && { case "$gl_cv_func_isnanf_works" in
+ *yes) true;;
+ *) false;;
+ esac
+ }; then
AC_DEFINE([HAVE_ISNANF_IN_LIBC], 1,
[Define if the isnan(float) function is available in libc.])
else
])
])
+dnl Test whether isnanf() recognizes a NaN (this fails on IRIX 6.5) and rejects
+dnl Infinity (this fails on Solaris 2.5.1).
+AC_DEFUN([gl_ISNANF_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether isnan(float) works], [gl_cv_func_isnanf_works],
+ [
+ AC_TRY_RUN([
+#include <math.h>
+#ifdef isnan
+# undef isnanf
+# define isnanf(x) isnan ((float)(x))
+#endif
+/* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */
+#ifdef __DECC
+static float
+NaN ()
+{
+ static float zero = 0.0f;
+ return zero / zero;
+}
+#else
+# define NaN() (0.0f / 0.0f)
+#endif
+int main()
+{
+ if (!isnanf (NaN ()))
+ return 1;
+ if (isnanf (1.0f / 0.0f))
+ return 1;
+ return 0;
+}], [gl_cv_func_isnanf_works=yes], [gl_cv_func_isnanf_works=no],
+ [case "$host_os" in
+ irix* | solaris*) gl_cv_func_isnanf_works="guessing no";;
+ *) gl_cv_func_isnanf_works="guessing yes";;
+ esac
+ ])
+ ])
+])
+
AC_DEFUN([gl_FLOAT_EXPONENT_LOCATION],
[
AC_CACHE_CHECK([where to find the exponent in a 'float'],
],
[gl_cv_cc_float_expbit0=`cat conftest.out`],
[gl_cv_cc_float_expbit0="unknown"],
- [gl_cv_cc_double_expbit0="word 0 bit 23"])
+ [gl_cv_cc_float_expbit0="word 0 bit 23"])
rm -f conftest.out
])
case "$gl_cv_cc_float_expbit0" in