fold-const.c (fold): When seeing if D & ~C != 0 to fold (A & C) == D into 0, fold ~C.

	* fold-const.c (fold) [EQ_EXPR]: When seeing if D & ~C != 0 to
	fold (A & C) == D into 0, fold ~C.  Similarly, for the case
	where | is used instead of &.

	* testsuite/gcc.dg/tree-ssa/20041002-1.c: New.

From-SVN: r88449

gcc/ChangeLog

 2004-10-03  Kazu Hirata  <kazu@cs.umass.edu>
 
+	* fold-const.c (fold) [EQ_EXPR]: When seeing if D & ~C != 0 to
+	fold (A & C) == D into 0, fold ~C.  Similarly, for the case
+	where | is used instead of &.
+
+2004-10-03  Kazu Hirata  <kazu@cs.umass.edu>
+
 	* ginclude/stddef.h: Fix a comment typo.
 
 2004-10-03  Eric Botcazou  <ebotcazou@libertysurf.fr>

gcc/fold-const.c

@@ -8400,11 +8400,11 @@ fold (tree expr)
 	  && TREE_CODE (arg1) == INTEGER_CST
 	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
 	{
-	  tree dandnotc
-	    = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
-			    arg1, build1 (BIT_NOT_EXPR,
-					  TREE_TYPE (TREE_OPERAND (arg0, 1)),
-					  TREE_OPERAND (arg0, 1))));
+	  tree notc = fold (build1 (BIT_NOT_EXPR,
+				    TREE_TYPE (TREE_OPERAND (arg0, 1)),
+				    TREE_OPERAND (arg0, 1)));
+	  tree dandnotc = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
+					arg1, notc));
 	  tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
 	  if (integer_nonzerop (dandnotc))
 	    return omit_one_operand (type, rslt, arg0);
@@ -8417,10 +8417,9 @@ fold (tree expr)
 	  && TREE_CODE (arg1) == INTEGER_CST
 	  && TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST)
 	{
-	  tree candnotd
-	    = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
-			    TREE_OPERAND (arg0, 1),
-			    build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1)));
+	  tree notd = fold (build1 (BIT_NOT_EXPR, TREE_TYPE (arg1), arg1));
+	  tree candnotd = fold (build2 (BIT_AND_EXPR, TREE_TYPE (arg0),
+					TREE_OPERAND (arg0, 1), notd));
 	  tree rslt = code == EQ_EXPR ? integer_zero_node : integer_one_node;
 	  if (integer_nonzerop (candnotd))
 	    return omit_one_operand (type, rslt, arg0);

gcc/testsuite/ChangeLog

+2004-10-03  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* gcc.dg/tree-ssa/20041002-1.c: New.
+
 2004-10-03  Paul Brook  <paul@codesourcery.com>
 
 	* gfortran.dg/pr17286.f90: Add dg-do line.  Explicitly test bug,

gcc/testsuite/gcc.dg/tree-ssa/20041002-1.c

+/* PR tree-optimization/16632
+   fold() failed to see the following "if" statements never trigger.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-ssa" } */
+
+int
+foo (int i)
+{
+  if ((i | 3) == 1)
+    return 1;
+  return 0;
+}
+
+int
+bar (int i)
+{
+  if ((i & 4) == 2)
+    return 1;
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "if" 0 "ssa" } } */