From f7b7b0aab82d50165f9d3fb375cd506af999a288 Mon Sep 17 00:00:00 2001
From: Marek Polacek <polacek@redhat.com>
Date: Fri, 17 Jul 2015 16:03:27 +0000
Subject: [PATCH] fold-const.c (fold_binary_loc): Move A - (A & B) into ~B & A
 ...

	* fold-const.c (fold_binary_loc): Move A - (A & B) into ~B & A ...
	* match.pd: ... here.

	* gcc.dg/fold-minus-7.c: New test.

From-SVN: r225938
---
 gcc/ChangeLog                       |  5 ++++
 gcc/fold-const.c                    | 24 -------------------
 gcc/match.pd                        |  6 +++++
 gcc/testsuite/ChangeLog             |  4 ++++
 gcc/testsuite/gcc.dg/fold-minus-7.c | 36 +++++++++++++++++++++++++++++
 5 files changed, 51 insertions(+), 24 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/fold-minus-7.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d36d6b57b7b..f0d08e96e19 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-17  Marek Polacek  <polacek@redhat.com>
+
+	* fold-const.c (fold_binary_loc): Move A - (A & B) into ~B & A ...
+	* match.pd: ... here.
+
 2015-07-17  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* config/nvptx/mkoffload.c (process): Constify target data.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 93dd29d6729..fa321f455d2 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -9777,30 +9777,6 @@ fold_binary_loc (location_t loc,
 
       if (! FLOAT_TYPE_P (type))
 	{
-	  /* Fold A - (A & B) into ~B & A.  */
-	  if (!TREE_SIDE_EFFECTS (arg0)
-	      && TREE_CODE (arg1) == BIT_AND_EXPR)
-	    {
-	      if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
-		{
-		  tree arg10 = fold_convert_loc (loc, type,
-						 TREE_OPERAND (arg1, 0));
-		  return fold_build2_loc (loc, BIT_AND_EXPR, type,
-				      fold_build1_loc (loc, BIT_NOT_EXPR,
-						   type, arg10),
-				      fold_convert_loc (loc, type, arg0));
-		}
-	      if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
-		{
-		  tree arg11 = fold_convert_loc (loc,
-						 type, TREE_OPERAND (arg1, 1));
-		  return fold_build2_loc (loc, BIT_AND_EXPR, type,
-				      fold_build1_loc (loc, BIT_NOT_EXPR,
-						   type, arg11),
-				      fold_convert_loc (loc, type, arg0));
-		}
-	    }
-
 	  /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
 	     any power of 2 minus 1.  */
 	  if (TREE_CODE (arg0) == BIT_AND_EXPR
diff --git a/gcc/match.pd b/gcc/match.pd
index c335ada567e..700a6922295 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -662,6 +662,12 @@ along with GCC; see the file COPYING3.  If not see
  (bit_ior:c (bit_and:cs @0 (bit_not @2)) (bit_and:cs @1 @2))
  (bit_xor (bit_and (bit_xor @0 @1) @2) @0))
 
+/* Fold A - (A & B) into ~B & A.  */
+(simplify
+ (minus (convert? @0) (convert?:s (bit_and:cs @0 @1)))
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
+      && tree_nop_conversion_p (type, TREE_TYPE (@1)))
+  (convert (bit_and (bit_not @1) @0))))
 
 /* Associate (p +p off1) +p off2 as (p +p (off1 + off2)).  */
 (simplify
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5462c1fd020..8a30395e348 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2015-07-17  Marek Polacek  <polacek@redhat.com>
+
+	* gcc.dg/fold-minus-7.c: New test.
+
 2015-07-17  Alessandro Fanfarillo  <fanfarillo.gcc@gmail.com>
 
 	* gfortran.dg/co_reduce_1.f90: New file.
diff --git a/gcc/testsuite/gcc.dg/fold-minus-7.c b/gcc/testsuite/gcc.dg/fold-minus-7.c
new file mode 100644
index 00000000000..7a49faa9ff6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/fold-minus-7.c
@@ -0,0 +1,36 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+f1 (int a, int b)
+{
+  int tem = a & b;
+  return a - tem;
+}
+
+int
+f2 (int a, int b)
+{
+  int tem = b & a;
+  return a - tem;
+}
+
+int
+f3 (unsigned int a, int b)
+{
+  return a - (a & b);
+}
+
+int
+f4 (int a, unsigned int b)
+{
+  return a - (a & b);
+}
+
+int
+f5 (int a, int b)
+{
+  return a - (unsigned) (b & a);
+}
+
+/* { dg-final { scan-tree-dump-not " - " "cddce1" } } */