re PR middle-end/25529 ((unsigned * 2)/2 is not changed into unsigned &0x7FFFFFFF)

2015-08-13  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>

	PR middle-end/25529
	* match.pd (div (mult @0 @1) @1) : New simplifier.

From-SVN: r226847

gcc/ChangeLog

+2015-08-13  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
+
+	PR middle-end/25529
+	* match.pd (div (mult @0 @1) @1) : New simplifier.
+
 2015-08-12  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	PR target/67071

gcc/match.pd

@@ -296,6 +296,14 @@ along with GCC; see the file COPYING3.  If not see
  (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
   (bit_and @0 (negate @1))))
 
+/* Simplify (t * 2) / 2) -> t.  */
+(for div (trunc_div ceil_div floor_div round_div exact_div)
+ (simplify
+  (div (mult @0 @1) @1)
+  (if (ANY_INTEGRAL_TYPE_P (type)
+       && TYPE_OVERFLOW_UNDEFINED (type))
+   @0)))
+
 /* X % Y is smaller than Y.  */
 (for cmp (lt ge)
  (simplify