match.pd: Three new patterns

[Marek Polacek <polacek at redhat dot com>]

This patch brings three new patterns for match.pd.  I think these are
rare, but it shouldn't hurt to have them.
(I suppose you'd be happier if I was moving patterns from fold-const to
match.pd.  I'll work on that as well.)

Given previous discussion, I don't think there's much to say otherwise,
but I'd appreciate if someone could glance over this.

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2015-06-12  Marek Polacek  <polacek@redhat.com>

	* match.pd ((x & y) + (x ^ y) -> x | y,
	(x & y) + (x | y) -> x + y,
	(x | y) - (x ^ y) -> x & y): New patterns.

	* gcc.dg/fold-plus-1.c: New test.
	* gcc.dg/fold-plus-2.c: New test.
	* gcc.dg/fold-minus-2.c: New test.

--- gcc/match.pd
+++ gcc/match.pd
@@ -325,6 +325,21 @@ along with GCC; see the file COPYING3.  If not see
  (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
  (bit_xor @0 @1))
 
+/* (x & y) + (x ^ y) -> x | y */
+(simplify
+ (plus:c (bit_and @0 @1) (bit_xor @0 @1))
+ (bit_ior @0 @1))
+
+/* (x & y) + (x | y) -> x + y */
+(simplify
+ (plus:c (bit_and @0 @1) (bit_ior @0 @1))
+ (plus @0 @1))
+
+/* (x | y) - (x ^ y) -> x & y */
+(simplify
+ (minus (bit_ior @0 @1) (bit_xor @0 @1))
+ (bit_and @0 @1))
+
 (simplify
  (abs (negate @0))
  (abs @0))
--- gcc/testsuite/gcc.dg/fold-plus-1.c
+++ gcc/testsuite/gcc.dg/fold-plus-1.c
@@ -0,0 +1,70 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a ^ b;
+  return tem1 + tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a ^ b;
+  return tem1 + tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b ^ a;
+  return tem1 + tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b ^ a;
+  return tem1 + tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a ^ b;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b ^ a;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */
--- gcc/testsuite/gcc.dg/fold-plus-2.c
+++ gcc/testsuite/gcc.dg/fold-plus-2.c
@@ -0,0 +1,69 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = a | b;
+  return tem1 + tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = a | b;
+  return tem1 + tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a & b;
+  int tem2 = b | a;
+  return tem1 + tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b & a;
+  int tem2 = b | a;
+  return tem1 + tem2;
+}
+
+int
+fn5 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn6 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a & b;
+  return tem1 + tem2;
+}
+
+int
+fn7 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+int
+fn8 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b & a;
+  return tem1 + tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */
--- gcc/testsuite/gcc.dg/fold-minus-2.c
+++ gcc/testsuite/gcc.dg/fold-minus-2.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = a ^ b;
+  return tem1 - tem2;
+}
+
+int
+fn2 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = a ^ b;
+  return tem1 - tem2;
+}
+
+int
+fn3 (int a, int b)
+{
+  int tem1 = a | b;
+  int tem2 = b ^ a;
+  return tem1 - tem2;
+}
+
+int
+fn4 (int a, int b)
+{
+  int tem1 = b | a;
+  int tem2 = b ^ a;
+  return tem1 - tem2;
+}
+
+/* { dg-final { scan-tree-dump-not " \\^ " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */

	Marek