re PR tree-optimization/68906 (ICE at -O3 on x86_64-linux-gnu: verify_ssa failed)

gcc/

2015-12-18  Yuri Rumyantsev  <ysrumyan@gmail.com>

	PR tree-optimization/68906
	* tree-ssa-loop-unswitch.c (tree_unswitch_outer_loop): Add check
	that an exit block belongs to LOOP.

gcc/testsuite/

2015-12-18  Yuri Rumyantsev  <ysrumyan@gmail.com>

	PR tree-optimization/68906
	* gcc.dg/torture/pr68906.c: New test.

From-SVN: r231812

gcc/ChangeLog

+2015-12-18  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR tree-optimization/68906
+	* tree-ssa-loop-unswitch.c (tree_unswitch_outer_loop): Add check
+	that an exit block belongs to LOOP.
+
 2015-12-18  Ilya Enkovich  <enkovich.gnu@gmail.com>
 
 	PR tree-optimization/68956

gcc/testsuite/ChangeLog

+2015-12-18  Yuri Rumyantsev  <ysrumyan@gmail.com>
+
+	PR tree-optimization/68906
+	* gcc.dg/torture/pr68906.c: New test.
+
 2015-12-18  Ilya Enkovich  <enkovich.gnu@gmail.com>
 
 	PR tree-optimization/68956

gcc/testsuite/gcc.dg/torture/pr68906.c

+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+int a;
+volatile int b;
+short c, d;
+int
+fn1 ()
+{
+  int e;
+  for (;;)
+    {
+      a = 3;
+      if (c)
+	continue;
+      e = 0;
+      for (; e > -30; e--)
+	if (b)
+	  {
+	    int f = e;
+	    return d;
+	  }
+    }
+}

gcc/tree-ssa-loop-unswitch.c

@@ -429,9 +429,9 @@ tree_unswitch_outer_loop (struct loop *loop)
   gcc_assert (loop->inner);
   if (loop->inner->next)
     return false;
-  /* Accept loops with single exit only.  */
+  /* Accept loops with single exit only which is not from inner loop.  */
   exit = single_exit (loop);
-  if (!exit)
+  if (!exit || exit->src->loop_father != loop)
     return false;
   /* Check that phi argument of exit edge is not defined inside loop.  */
   if (!check_exit_phi (loop))