libgcc: check for fenv.h in dfp configure check

uClibc can be built without fenv support, extend the configure check for
decimal floating point to probe the existance of fenv.h, too.

libgcc/ChangeLog:

2013-03-24  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>

	* configure.ac (libgcc_cv_dfp): Extend check to probe fenv.h
	availability.
	* configure: Regenerate

From-SVN: r204562

libgcc/ChangeLog

+2013-11-08  Bernhard Reutner-Fischer  <aldot@gcc.gnu.org>
+
+	* configure.ac (libgcc_cv_dfp): Extend check to probe fenv.h
+	availability.
+	* configure: Regenerate
+
 2013-11-07  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/sfp-exceptions.c (__sfp_handle_exceptions): Handle

libgcc/configure

@@ -4066,7 +4066,20 @@ if test "${libgcc_cv_dfp+set}" = set; then :
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
+
+#include <fenv.h>
+
+int
+main ()
+{
+
 _Decimal32 x;
+int fe_except =
+  FE_INVALID|FE_DIVBYZERO|FE_OVERFLOW|FE_UNDERFLOW|FE_INEXACT;
+
+  ;
+  return 0;
+}
 _ACEOF
 if ac_fn_c_try_compile "$LINENO"; then :
   libgcc_cv_dfp=yes

libgcc/configure.ac

@@ -182,7 +182,14 @@ AC_SUBST(long_double_type_size)
 
 # Check for decimal float support.
 AC_CACHE_CHECK([whether decimal floating point is supported], [libgcc_cv_dfp],
-	       [AC_COMPILE_IFELSE([_Decimal32 x;], [libgcc_cv_dfp=yes],
+	       [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <fenv.h>
+]], [[
+_Decimal32 x;
+int fe_except =
+  FE_INVALID|FE_DIVBYZERO|FE_OVERFLOW|FE_UNDERFLOW|FE_INEXACT;
+]])],
+				  [libgcc_cv_dfp=yes],
 				  [libgcc_cv_dfp=no])])
 decimal_float=$libgcc_cv_dfp
 AC_SUBST(decimal_float)