~X & Y to X ^ Y in some cases

2016-05-17  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* match.pd (~X & Y): New transformation.

gcc/testsuite/
	* gcc.dg/tree-ssa/pr69270.c: Adjust.
	* gcc.dg/tree-ssa/andnot-1.c: New testcase.

From-SVN: r236337

gcc/ChangeLog

 2016-05-17  Marc Glisse  <marc.glisse@inria.fr>
 
+	* match.pd (~X & Y): New transformation.
+
+2016-05-17  Marc Glisse  <marc.glisse@inria.fr>
+
 	* tree-vrp.c (simplify_truth_ops_using_ranges): Set range
 	information for new SSA_NAME.
 	(simplify_conversion_using_ranges): Get range through get_range_info

gcc/match.pd

@@ -503,6 +503,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  (bit_ior:c (bit_and @0 INTEGER_CST@2) (bit_and (bit_not @0) INTEGER_CST@1))
  (if (wi::bit_not (@2) == @1)
   (bit_xor @0 @1)))
+/* Simplify (~X & Y) to X ^ Y if we know that (X & ~Y) is 0.  */
+#if GIMPLE
+(simplify
+ (bit_and (bit_not SSA_NAME@0) INTEGER_CST@1)
+ (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+      && (get_nonzero_bits (@0) & wi::bit_not (@1)) == 0)
+  (bit_xor @0 @1)))
+#endif
 
 /* X % Y is smaller than Y.  */
 (for cmp (lt ge)

gcc/testsuite/ChangeLog

 2016-05-17  Marc Glisse  <marc.glisse@inria.fr>
 
 	* gcc.dg/tree-ssa/pr69270.c: Adjust.
+	* gcc.dg/tree-ssa/andnot-1.c: New testcase.
+
+2016-05-17  Marc Glisse  <marc.glisse@inria.fr>
+
+	* gcc.dg/tree-ssa/pr69270.c: Adjust.
 	* gcc.dg/tree-ssa/vrp99.c: New testcase.
 
 2016-05-17  Jiong Wang  <jiong.wang@arm.com>

gcc/testsuite/gcc.dg/tree-ssa/andnot-1.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized-raw" } */
+
+unsigned f(unsigned i){
+  i >>= __SIZEOF_INT__ * __CHAR_BIT__ - 3;
+  i = ~i;
+  return i & 7;
+}
+
+/* { dg-final { scan-tree-dump "bit_xor_expr" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "bit_not_expr" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "bit_and_expr" "optimized" } } */