Simplify 3*x == 3*y for wrapping types

2017-06-28  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* match.pd ((X & ~Y) | (~X & Y)): Generalize to + and ^.
	(x * C EQ/NE y * C): New transformation.

gcc/testsuite/
	* gcc.dg/tree-ssa/addadd.c: Remove test duplicated in addadd-2.c.
	* gcc.dg/tree-ssa/mulcmp-1.c: New file.

From-SVN: r249732

gcc/ChangeLog

+2017-06-28  Marc Glisse  <marc.glisse@inria.fr>
+
+	* match.pd ((X & ~Y) | (~X & Y)): Generalize to + and ^.
+	(x * C EQ/NE y * C): New transformation.
+
 2017-06-28  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	* genmultilib (combination_space): Accept '+' in option names.

gcc/match.pd

@@ -642,14 +642,15 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  (minus (bit_and:cs @0 @1) (bit_and:cs @0 (bit_not @1)))
   (minus @1 (bit_xor @0 @1)))
 
-/* Simplify (X & ~Y) | (~X & Y) -> X ^ Y.  */
-(simplify
- (bit_ior (bit_and:c @0 (bit_not @1)) (bit_and:c (bit_not @0) @1))
-  (bit_xor @0 @1))
-(simplify
- (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) |^+ (~X & Y) -> X ^ Y.  */
+(for op (bit_ior bit_xor plus)
+ (simplify
+  (op (bit_and:c @0 (bit_not @1)) (bit_and:c (bit_not @0) @1))
+   (bit_xor @0 @1))
+ (simplify
+  (op: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))))
 
 /* PR53979: Transform ((a ^ b) | a) -> (a | b) */
 (simplify
@@ -1097,6 +1098,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
        && tree_expr_nonzero_p (@1))
    (cmp @0 @2))))
 
+/* For integral types with wrapping overflow and C odd fold
+   x * C EQ/NE y * C into x EQ/NE y.  */
+(for cmp (eq ne)
+ (simplify
+  (cmp (mult @0 INTEGER_CST@1) (mult @2 @1))
+  (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
+       && TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))
+       && (TREE_INT_CST_LOW (@1) & 1) != 0)
+   (cmp @0 @2))))
+
 /* For integral types with undefined overflow and C != 0 fold
    x * C RELOP y * C into:
 

gcc/testsuite/ChangeLog

+2017-06-28  Marc Glisse  <marc.glisse@inria.fr>
+
+	* gcc.dg/tree-ssa/addadd.c: Remove test duplicated in addadd-2.c.
+	* gcc.dg/tree-ssa/mulcmp-1.c: New file.
+
 2017-06-28  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc.target/i386/cmov7.c (sgn): Renamed to ...

gcc/testsuite/gcc.dg/tree-ssa/addadd.c

@@ -23,11 +23,6 @@ int i(int x){
   x += __INT_MAX__;
   return x;
 }
-typedef int S __attribute__((vector_size(16)));
-void j(S*x){
-  *x += __INT_MAX__;
-  *x += __INT_MAX__;
-}
 
 /* { dg-final { scan-tree-dump-times " \\+ 24;" 2 "optimized" } } */
 /* { dg-final { scan-tree-dump-times "\\(unsigned int\\)" 2 "optimized" } } */

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

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized-raw" } */
+
+int f(unsigned a,unsigned b){
+    a *= 3;
+    b *= 3;
+    return a == b;
+}
+
+/* { dg-final { scan-tree-dump-not "mult_expr" "optimized" } } */