re PR sanitizer/81505 (ICE in tree-ssa-loop-manip.c:95 with -fsanitize=signed-integer-overflow)

2017-07-25  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.

From-SVN: r250494

gcc/ChangeLog

+2017-07-25  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/81505
+	* fold-const.c (fold_negate_const): TREE_OVERFLOW should be
+	sticky.
+
 2017-07-24  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	* config/rs6000/rs6000-cpus.def (ISA_2_6_MASKS_SERVER): Delete

gcc/fold-const.c

@@ -13702,8 +13702,8 @@ 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;
       }
 

gcc/testsuite/ChangeLog

+2017-07-25  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/81505
+	* gcc.dg/ubsan/pr81505.c: New testcase.
+
 2017-07-24  Daniel Santos  <daniel.santos@pobox.com>
 
 	PR testsuite/80759

gcc/testsuite/gcc.dg/ubsan/pr81505.c

+/* { 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;
+}