On Tue, 13 Jan 2015, Rasmus Villemoes wrote:
diff --git gcc/match.pd gcc/match.pd
index 81c4ee6..04a0bc4 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -262,6 +262,16 @@ along with GCC; see the file COPYING3. If not see
(abs tree_expr_nonnegative_p@0)
@0)
+/* x + (x & 1) -> (x + 1) & ~1 */
+(simplify
+ (plus @0 (bit_and @0 integer_onep@1))
+ (bit_and (plus @0 @1) (bit_not @1)))
+
+/* x | ~(x | y) -> x | ~y */
+(simplify
+ (bit_ior @0 (bit_not (bit_ior @0 @1)))
+ (bit_ior @0 (bit_not @1)))
You may want to consider using has_single_use (see other patterns).
--
Marc Glisse
