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

PR middle-end/25529
2015-07-24  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>

gcc/testsuite/ChangeLog:
	* gcc.dg/pr25529.c: New test.

gcc/ChangeLog:
	* match.pd (trunc_div (mult @0 integer_pow2p@1) @1) : New simplifier.

From-SVN: r226136

gcc/ChangeLog

+2015-07-24  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
+
+         PR middle-end/25529
+         * match.pd (trunc_div (mult @0 integer_pow2p@1) @1) : New simplifier.
+
 2015-07-23  Kugan Vivekanandarajah  <kuganv@linaro.org>
 
 	* config/arm/arm.c (arm_emit_movpair): Add REG_EQUAL notes to

gcc/match.pd

@@ -29,7 +29,8 @@ along with GCC; see the file COPYING3.  If not see
    integer_each_onep integer_truep
    real_zerop real_onep real_minus_onep
    CONSTANT_CLASS_P
-   tree_expr_nonnegative_p)
+   tree_expr_nonnegative_p
+   integer_pow2p)
 
 /* Operator lists.  */
 (define_operator_list tcc_comparison
@@ -280,6 +281,14 @@ along with GCC; see the file COPYING3.  If not see
 	&& integer_pow2p (@2) && tree_int_cst_sgn (@2) > 0)
    (bit_and @0 (convert (minus @1 { build_int_cst (TREE_TYPE (@1), 1); }))))))
 
+/* Simplify (unsigned t * 2)/2 -> unsigned t & 0x7FFFFFFF.  */
+(simplify
+ (trunc_div (mult @0 integer_pow2p@1) @1)
+ (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
+  (bit_and @0 { wide_int_to_tree
+		(type, wi::mask (TYPE_PRECISION (type) - wi::exact_log2 (@1),
+				 false, TYPE_PRECISION (type))); })))
+
 /* X % Y is smaller than Y.  */
 (for cmp (lt ge)
  (simplify

gcc/testsuite/ChangeLog

+2015-07-24  Naveen H.S  <Naveen.Hurugalawadi@caviumnetworks.com>
+
+	PR middle-end/25529
+	* gcc.dg/pr25529.c: New test.
+
 2015-07-23  Kugan Vivekanandarajah  <kuganv@linaro.org>
 
 	* gcc.target/arm/reg_equal_test.c: New test.

gcc/testsuite/gcc.dg/pr25529.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-require-effective-target int32 } */
+
+int
+f (unsigned t)
+{
+  return (t * 2) / 2;
+}
+
+/* { dg-final { scan-tree-dump "\& 2147483647" "optimized" } } */