re PR c/79731 (ICE: verify_gimple failed)

2017-02-28  Richard Biener  <rguenther@suse.de>

	PR middle-end/79731
	* fold-const.c (decode_field_reference): Reject out-of-bound
	accesses.

	* c-c++-common/torture/pr79731.c: New testcase.

From-SVN: r245779

gcc/ChangeLog

+2017-02-28  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/79731
+	* fold-const.c (decode_field_reference): Reject out-of-bound
+	accesses.
+
 2017-02-28  Jakub Jelinek  <jakub@redhat.com>
 
 	* config/i386/i386.c: Include intl.h.

gcc/fold-const.c

@@ -4133,7 +4133,11 @@ decode_field_reference (location_t loc, tree *exp_, HOST_WIDE_INT *pbitsize,
 			       punsignedp, preversep, pvolatilep);
   if ((inner == exp && and_mask == 0)
       || *pbitsize < 0 || offset != 0
-      || TREE_CODE (inner) == PLACEHOLDER_EXPR)
+      || TREE_CODE (inner) == PLACEHOLDER_EXPR
+      /* Reject out-of-bound accesses (PR79731).  */
+      || (! AGGREGATE_TYPE_P (TREE_TYPE (inner))
+	  && compare_tree_int (TYPE_SIZE (TREE_TYPE (inner)),
+			       *pbitpos + *pbitsize) < 0))
     return 0;
 
   *exp_ = exp;

gcc/testsuite/ChangeLog

 2017-02-28  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/79731
+	* c-c++-common/torture/pr79731.c: New testcase.
+
+2017-02-28  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/79732
 	* gcc.dg/torture/pr79732.c: New testcase.
 

gcc/testsuite/c-c++-common/torture/pr79731.c

+/* { dg-do compile } */
+/* { dg-additional-options "-Wno-psabi -w" } */
+
+typedef unsigned V __attribute__ ((vector_size (8)));
+V
+foo (unsigned x, V v)
+{
+  do {
+      v %= x;
+      x = 1;
+  } while (v[1]);
+  return v;
+}
+void fn2 ()
+{
+  V x = foo (5, (V) { 0, 1 });
+  if (x[0] || x[1] || x[2] || x[3]);
+}