This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[PATCH] Fix rotate discovery in fold-const.c (PR tree-optimization/65014)


Hi!

We pass the values after STRIP_NOPS to *ROTATE_EXPR build, which is
undesirable, as the testcase shows, the operand could very well end up being
a pointer rather than integer.
This patch fixes it by passing the original trees instead.
Alternatively we could fold_convert the STRIP_NOPS result to the original
type, but I'd be afraid that in the common case that would just create more
GC garbage.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2015-02-12  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/65014
	* fold-const.c (fold_binary_loc): When creating {L,R}ROTATE_EXPR,
	use original second operand of arg0 or arg1 instead of
	that adjusted by STRIP_NOPS.

	* gcc.c-torture/compile/pr65014.c: New test.

--- gcc/fold-const.c.jj	2015-01-22 19:30:59.000000000 +0100
+++ gcc/fold-const.c	2015-02-11 15:06:52.628078961 +0100
@@ -10261,7 +10261,9 @@ fold_binary_loc (location_t loc,
 		tem = build2_loc (loc, LROTATE_EXPR,
 				  TREE_TYPE (TREE_OPERAND (arg0, 0)),
 				  TREE_OPERAND (arg0, 0),
-				  code0 == LSHIFT_EXPR ? tree01 : tree11);
+				  code0 == LSHIFT_EXPR
+				  ? TREE_OPERAND (arg0, 1)
+				  : TREE_OPERAND (arg1, 1));
 		return fold_convert_loc (loc, type, tem);
 	      }
 	    else if (code11 == MINUS_EXPR)
@@ -10283,7 +10285,8 @@ fold_binary_loc (location_t loc,
 					       ? LROTATE_EXPR
 					       : RROTATE_EXPR),
 					      TREE_TYPE (TREE_OPERAND (arg0, 0)),
-					      TREE_OPERAND (arg0, 0), tree01));
+					      TREE_OPERAND (arg0, 0),
+					      TREE_OPERAND (arg0, 1)));
 	      }
 	    else if (code01 == MINUS_EXPR)
 	      {
@@ -10304,7 +10307,7 @@ fold_binary_loc (location_t loc,
 				? LROTATE_EXPR
 				: RROTATE_EXPR),
 			       TREE_TYPE (TREE_OPERAND (arg0, 0)),
-			       TREE_OPERAND (arg0, 0), tree11));
+			       TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1)));
 	      }
 	  }
       }
--- gcc/testsuite/gcc.c-torture/compile/pr65014.c.jj	2015-02-11 15:21:19.175681614 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr65014.c	2015-02-11 15:22:18.040703653 +0100
@@ -0,0 +1,10 @@
+/* PR tree-optimization/65014 */
+/* { dg-do compile { target int32plus } } */
+
+extern int x;
+
+unsigned
+foo (unsigned int y)
+{
+  return (y << ((__INTPTR_TYPE__) &x)) | (y >> (32 - ((__INTPTR_TYPE__) &x)));
+}

	Jakub


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]