match.pd ((x & y) ^ (x | y) -> x ^ y): New pattern.

	* match.pd ((x & y) ^ (x | y) -> x ^ y): New pattern.

	* gcc.dg/fold-xor-3.c: New test.

From-SVN: r224370

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index cfa86f6ac08b8aa1393b6e6653d4ae3bc01a92e2..6327ef5aeff14af821ecaa6ec8d4cc24e1206c29 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2015-06-11  Marek Polacek  <polacek@redhat.com>
+
+       * match.pd ((x & y) ^ (x | y) -> x ^ y): New pattern.
+
 2015-06-11  Marek Polacek  <polacek@redhat.com>
 
        * match.pd: Use single_use throughout.

diff --git a/gcc/match.pd b/gcc/match.pd
index 33fa717c8447a43b9fa2f1c89b356c70273724c0..9a1317e1f230eb78b000fa11af0c4a5f257707a6 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -320,6 +320,12 @@ along with GCC; see the file COPYING3.  If not see
   (bitop:c (rbitop:c @0 @1) (bit_not@2 @0))
   (bitop @1 @2)))
 
+/* (x & y) ^ (x | y) -> x ^ y */
+(simplify
+ (bit_xor:c (bit_and@2 @0 @1) (bit_ior@3 @0 @1))
+  (if (single_use (@2) && single_use (@3))
+   (bit_xor @0 @1)))
+
 (simplify
  (abs (negate @0))
  (abs @0))

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index cf2c0d6cc06f057e31dda716ab6c3bcf4ece2c4c..f5abd3d4de752fb6f9f8ff06a3ee4365d7e2ffab 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2015-06-11  Marek Polacek  <polacek@redhat.com>
+
+       * gcc.dg/fold-xor-3.c: New test.
+
 2015-06-11  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
        * gcc.target/arm/short-it-ifcvt-1.c: New test.

diff --git a/gcc/testsuite/gcc.dg/fold-xor-3.c b/gcc/testsuite/gcc.dg/fold-xor-3.c
new file mode 100644 (file)
index 0000000..c2c0af6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-xor-3.c
@@ -0,0 +1,37 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (signed int x, signed int y)
+{
+  signed int tem1 = x & y;
+  signed int tem2 = x | y;
+  return tem1 ^ tem2;
+}
+
+unsigned int
+fn2 (unsigned int x, unsigned int y)
+{
+  unsigned int tem1 = x & y;
+  unsigned int tem2 = x | y;
+  return tem1 ^ tem2;
+}
+
+int
+fn3 (signed int x, signed int y)
+{
+  signed int tem1 = x & y;
+  signed int tem2 = x | y;
+  return tem2 ^ tem1;
+}
+
+unsigned int
+fn4 (unsigned int x, unsigned int y)
+{
+  unsigned int tem1 = x & y;
+  unsigned int tem2 = x | y;
+  return tem2 ^ tem1;
+}
+
+/* { dg-final { scan-tree-dump-not " & " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\| " "cddce1" } } */