diff mbox

Fix PR81505

Message ID alpine.LSU.2.20.1707250902240.10808@zhemvz.fhfr.qr
State New
Headers show

Commit Message

Richard Biener July 25, 2017, 7:03 a.m. UTC 
The following makes fold_neagte_const properly handle TREE_OVERFLOW as
sticky (even if present on POINTER_TYPE constants).

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2017-06-25  Richard Biener  <rguenther@suse.de>

	PR middle-end/81505
	* fold-const.c (fold_negate_const): TREE_OVERFLOW should be
	sticky.

	* gcc.dg/ubsan/pr81505.c: New testcase.
diff mbox

Patch

Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c	(revision 250386)
+++ gcc/fold-const.c	(working copy)
@@ -13693,8 +13693,8 @@  fold_negate_const (tree arg0, tree type)
 	bool overflow;
 	wide_int val = wi::neg (arg0, &overflow);
 	t = force_fit_type (type, val, 1,
-			    (overflow | TREE_OVERFLOW (arg0))
-			    && !TYPE_UNSIGNED (type));
+			    (overflow && ! TYPE_UNSIGNED (type))
+			    || TREE_OVERFLOW (arg0));
 	break;
       }
 
Index: gcc/testsuite/gcc.dg/ubsan/pr81505.c
===================================================================
--- gcc/testsuite/gcc.dg/ubsan/pr81505.c	(nonexistent)
+++ gcc/testsuite/gcc.dg/ubsan/pr81505.c	(working copy)
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O3 -fsanitize=signed-integer-overflow" } */
+
+int a, b, c, h;
+
+int i[5][5];
+
+void
+fn1 ()
+{
+  int l = 0;
+
+  for (a = 0; a <= 3; a++)
+    for (b = 1; b >= 0; b -= 1)
+      l |= i[0][b];
+  c = l;
+}