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

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

	* gcc.dg/fold-minus-4.c: New test.
	* gcc.dg/fold-minus-5.c: New test.
	* c-c++-common/ubsan/overflow-add-5.c: New test.

From-SVN: r224834

6 files changed, 129 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ee2e8d7..80c07c8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-23  Marek Polacek  <polacek@redhat.com>
+
+	* match.pd ((x + y) - (x | y) -> x & y,
+	(x + y) - (x & y) -> x | y): New patterns.
+
 2015-06-23  Ludovic Courtès  <ludo@gnu.org>
 
 	PR 65711
diff --git a/gcc/match.pd b/gcc/match.pd
index badb80a..9c88e3e 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -343,6 +343,20 @@ along with GCC; see the file COPYING3.  If not see
  (plus:c (bit_and @0 @1) (bit_ior @0 @1))
  (plus @0 @1))
 
+/* (x + y) - (x | y) -> x & y */
+(simplify
+ (minus (plus @0 @1) (bit_ior @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type)
+      && !TYPE_SATURATING (type))
+  (bit_and @0 @1)))
+
+/* (x + y) - (x & y) -> x | y */
+(simplify
+ (minus (plus @0 @1) (bit_and @0 @1))
+ (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type)
+      && !TYPE_SATURATING (type))
+  (bit_ior @0 @1)))
+
 /* (x | y) - (x ^ y) -> x & y */
 (simplify
  (minus (bit_ior @0 @1) (bit_xor @0 @1))
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 19e4a7b..f305d81 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-06-23  Marek Polacek  <polacek@redhat.com>
+
+	* gcc.dg/fold-minus-4.c: New test.
+	* gcc.dg/fold-minus-5.c: New test.
+	* c-c++-common/ubsan/overflow-add-5.c: New test.
+
 2015-06-23  James Greenhalgh  <james.greenhalgh@arm.com>
 
 	Add missing testcase from r224672.
diff --git a/gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c b/gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
new file mode 100644
index 0000000..905a60a
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/ubsan/overflow-add-5.c
@@ -0,0 +1,30 @@
+/* { dg-do run } */
+/* { dg-options "-fsanitize=signed-integer-overflow" } */
+
+int __attribute__ ((noinline))
+foo (int i, int j)
+{
+  return (i + j) - (i | j);
+}
+
+/* { dg-output "signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 2147483647 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+
+int __attribute__ ((noinline))
+bar (int i, int j)
+{
+  return (i + j) - (i & j);
+}
+
+/* { dg-output "\[^\n\r]*signed integer overflow: 2147483647 \\+ 1 cannot be represented in type 'int'\[^\n\r]*(\n|\r\n|\r)" } */
+/* { dg-output "\[^\n\r]*signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'" } */
+
+int
+main ()
+{
+  int r = foo (__INT_MAX__, 1);
+  asm volatile ("" : "+g" (r));
+  r = bar (__INT_MAX__, 1);
+  asm volatile ("" : "+g" (r));
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/fold-minus-4.c b/gcc/testsuite/gcc.dg/fold-minus-4.c
new file mode 100644
index 0000000..2d76b4f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-minus-4.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" } } */
diff --git a/gcc/testsuite/gcc.dg/fold-minus-5.c b/gcc/testsuite/gcc.dg/fold-minus-5.c
new file mode 100644
index 0000000..a31e1cc
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-minus-5.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" } } */