-# truncf.m4 serial 5
-dnl Copyright (C) 2007, 2010-2011 Free Software Foundation, Inc.
+# truncf.m4 serial 9
+dnl Copyright (C) 2007, 2010-2013 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.
dnl Persuade glibc <math.h> to declare truncf().
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
dnl Test whether truncf() is declared.
- AC_CHECK_DECLS([truncf], , , [#include <math.h>])
+ AC_CHECK_DECLS([truncf], , , [[#include <math.h>]])
if test "$ac_cv_have_decl_truncf" = yes; then
dnl Test whether truncf() can be used without libm.
TRUNCF_LIBM=?
fi
m4_ifdef([gl_FUNC_TRUNCF_IEEE], [
if test $gl_truncf_required = ieee && test $REPLACE_TRUNCF = 0; then
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CACHE_CHECK([whether truncf works according to ISO C 99 with IEC 60559],
[gl_cv_func_truncf_ieee],
[
#include <math.h>
]gl_FLOAT_MINUS_ZERO_CODE[
]gl_FLOAT_SIGNBIT_CODE[
-int main()
+static float dummy (float f) { return 0; }
+int main (int argc, char *argv[])
{
+ float (*my_truncf) (float) = argc ? truncf : dummy;
/* Test whether truncf (-0.0f) is -0.0f. */
- if (signbitf (minus_zerof) && !signbitf (truncf (minus_zerof)))
+ if (signbitf (minus_zerof) && !signbitf (my_truncf (minus_zerof)))
return 1;
return 0;
}
]])],
[gl_cv_func_truncf_ieee=yes],
[gl_cv_func_truncf_ieee=no],
- [gl_cv_func_truncf_ieee="guessing no"])
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_truncf_ieee="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_truncf_ieee="guessing no" ;;
+ esac
+ ])
LIBS="$save_LIBS"
])
case "$gl_cv_func_truncf_ieee" in