m68k/cf: define __signbit/__signbitf as inlines

ports/ChangeLog.m68k

@@ -1,5 +1,7 @@
 2012-08-08  Andreas Schwab  <schwab@linux-m68k.org>
 
+	* sysdeps/m68k/coldfire/fpu/bits/mathinline.h: New file.
+
 	* sysdeps/unix/sysv/linux/m68k/coldfire/nptl/bits/atomic.h
 	(atomic_compare_and_exchange_val_acq) [!SHARED]: Add cast to avoid
 	warning.

ports/sysdeps/m68k/coldfire/fpu/bits/mathinline.h

@@ -0,0 +1,44 @@
+/* Inline math functions for Coldfire.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _MATH_H
+# error "Never use <bits/mathinline.h> directly; include <math.h> instead."
+#endif
+
+#ifndef __extern_always_inline
+# define __MATH_INLINE __inline
+#else
+# define __MATH_INLINE __extern_always_inline
+#endif
+
+#if defined __USE_ISOC99 && defined __GNUC__
+
+/* Test for negative number.  Used in the signbit macro.  */
+__MATH_INLINE int
+__NTH (__signbitf (float __x))
+{
+  return __builtin_signbitf (__x);
+}
+
+__MATH_INLINE int
+__NTH (__signbit (double __x))
+{
+  return __builtin_signbit (__x);
+}
+
+#endif