re PR middle-end/23670 (Fold does not fold (a|b)&b to b likewise for (a&b) | b to b)

	PR middle-end/23670
	* fold-const.c (fold_binary) <BIT_IOR_EXPR>: Optimize (X&Y)|Y into
	(X,Y) and the corresponding symmetry related transformations.
	(fold_binary) <BIT_AND_EXPR>: Likewise, optimize (X|Y)&Y into
	(X,Y) and its symmetry related transformations.

	* gcc.dg/tree-ssa/andor-2.c: New test case.

From-SVN: r110997

4 files changed, 105 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a5336bb..a134098 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,13 @@
 2006-02-14  Roger Sayle  <roger@eyesopen.com>
 
+	PR middle-end/23670
+	* fold-const.c (fold_binary) <BIT_IOR_EXPR>: Optimize (X&Y)|Y into
+	(X,Y) and the corresponding symmetry related transformations.
+	(fold_binary) <BIT_AND_EXPR>: Likewise, optimize (X|Y)&Y into
+	(X,Y) and its symmetry related transformations.
+
+2006-02-14  Roger Sayle  <roger@eyesopen.com>
+
         * dojump.c (do_compare_rtx_and_jump): Also handle multi-word GTU
 	and GEU.
 
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 03c9d1c..2683dab 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -8161,6 +8161,26 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
 				arg1);
 	}
 
+      /* (X & Y) | Y is (X, Y).  */
+      if (TREE_CODE (arg0) == BIT_AND_EXPR
+	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
+      /* (X & Y) | X is (Y, X).  */
+      if (TREE_CODE (arg0) == BIT_AND_EXPR
+	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+	  && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
+      /* X | (X & Y) is (Y, X).  */
+      if (TREE_CODE (arg1) == BIT_AND_EXPR
+	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
+	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
+	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
+      /* X | (Y & X) is (Y, X).  */
+      if (TREE_CODE (arg1) == BIT_AND_EXPR
+	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
+
       t1 = distribute_bit_expr (code, type, arg0, arg1);
       if (t1 != NULL_TREE)
 	return t1;
@@ -8313,6 +8333,26 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
 			    fold_build2 (BIT_AND_EXPR, type,
 					 TREE_OPERAND (arg0, 1), arg1));
 
+      /* (X | Y) & Y is (X, Y).  */
+      if (TREE_CODE (arg0) == BIT_IOR_EXPR
+	  && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 0));
+      /* (X | Y) & X is (Y, X).  */
+      if (TREE_CODE (arg0) == BIT_IOR_EXPR
+	  && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0)
+	  && reorder_operands_p (TREE_OPERAND (arg0, 1), arg1))
+	return omit_one_operand (type, arg1, TREE_OPERAND (arg0, 1));
+      /* X & (X | Y) is (Y, X).  */
+      if (TREE_CODE (arg1) == BIT_IOR_EXPR
+	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0)
+	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 1)))
+	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 1));
+      /* X & (Y | X) is (Y, X).  */
+      if (TREE_CODE (arg1) == BIT_IOR_EXPR
+	  && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
+	  && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
+	return omit_one_operand (type, arg0, TREE_OPERAND (arg1, 0));
+
       t1 = distribute_bit_expr (code, type, arg0, arg1);
       if (t1 != NULL_TREE)
 	return t1;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5d4bfaf..d2319a1 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2006-02-14  Roger Sayle  <roger@eyesopen.com>
+
+	PR middle-end/23670
+	* gcc.dg/tree-ssa/andor-2.c: New test case.
+
 2006-02-14  Thomas Koenig  <Thomas.Koenig@online.de>
 
         PR fortran/25045
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/andor-2.c b/gcc/testsuite/gcc.dg/tree-ssa/andor-2.c
new file mode 100644
index 0000000..cdc00b7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/andor-2.c
@@ -0,0 +1,52 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-original" } */
+
+int test1(int a, int b)
+{
+  return (a & b) | b;
+}
+
+int test2(int c, int d)
+{
+  return (c & d) | c;
+}
+
+int test3(int e, int f)
+{
+  return e | (e & f);
+}
+
+int test4(int g, int h)
+{
+  return g | (h & g);
+}
+
+int test5(int i, int j)
+{
+  return (i | j) & j;
+}
+
+int test6(int k, int l)
+{
+  return (k | l) & k;
+}
+
+int test7(int m, int n)
+{
+  return m & (m | n);
+}
+
+int test8(int o, int p)
+{
+  return o & (p | o);
+}
+
+/* { dg-final { scan-tree-dump-times "return b;" 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "return c;" 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "return e;" 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "return g;" 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "return j;" 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "return k;" 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "return m;" 1 "original" } } */
+/* { dg-final { scan-tree-dump-times "return o;" 1 "original" } } */
+/* { dg-final { cleanup-tree-dump "original" } } */