[partial backport of gcc-4.8/trunk r195574, needed by partial 198772
 backport, which is needed by PR57980 fix <mikpe@it.uu.se>]

gcc/

2013-01-30  Georg-Johann Lay  <avr@gjlay.de>

	PR tree-optimization/56064
	* fixed-value.c (fixed_from_double_int): New function.
	* fixed-value.h (fixed_from_double_int): New prototype.

--- gcc-4.7.3/gcc/fixed-value.c.~1~	2010-11-30 12:41:24.000000000 +0100
+++ gcc-4.7.3/gcc/fixed-value.c	2013-08-10 18:16:33.284220675 +0200
@@ -81,6 +81,24 @@ check_real_for_fixed_mode (REAL_VALUE_TY
   return FIXED_OK;
 }
 
+
+/* Construct a CONST_FIXED from a bit payload and machine mode MODE.
+   The bits in PAYLOAD are used verbatim.  */
+
+FIXED_VALUE_TYPE
+fixed_from_double_int (double_int payload, enum machine_mode mode)
+{
+  FIXED_VALUE_TYPE value;
+
+  gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_DOUBLE_INT);
+
+  value.data = payload;
+  value.mode = mode;
+
+  return value;
+}
+
+
 /* Initialize from a decimal or hexadecimal string.  */
 
 void
--- gcc-4.7.3/gcc/fixed-value.h.~1~	2009-04-22 20:29:36.000000000 +0200
+++ gcc-4.7.3/gcc/fixed-value.h	2013-08-10 18:16:56.564181277 +0200
@@ -49,6 +49,11 @@ extern FIXED_VALUE_TYPE fconst1[MAX_FCON
   const_fixed_from_fixed_value (r, m)
 extern rtx const_fixed_from_fixed_value (FIXED_VALUE_TYPE, enum machine_mode);
 
+/* Construct a FIXED_VALUE from a bit payload and machine mode MODE.
+   The bits in PAYLOAD are used verbatim.  */
+extern FIXED_VALUE_TYPE fixed_from_double_int (double_int,
+						     enum machine_mode);
+
 /* Initialize from a decimal or hexadecimal string.  */
 extern void fixed_from_string (FIXED_VALUE_TYPE *, const char *,
 			       enum machine_mode);