Don't allow latch with phi in try_transform_to_exit_first_loop_alt

2016-01-11  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/69109
	* tree-parloops.c (try_transform_to_exit_first_loop_alt): Don't allow
	latch with phi.

	* gcc.dg/autopar/pr69109-2.c: New test.
	* gcc.dg/autopar/pr69109.c: New test.

From-SVN: r232212

gcc/ChangeLog

 2016-01-11  Tom de Vries  <tom@codesourcery.com>
 
+	PR tree-optimization/69109
+	* tree-parloops.c (try_transform_to_exit_first_loop_alt): Don't allow
+	latch with phi.
+
+2016-01-11  Tom de Vries  <tom@codesourcery.com>
+
 	PR tree-optimization/69108
 	* tree-parloops.c (gather_scalar_reductions): Handle case that outer phi
 	res is not used in a phi.

gcc/testsuite/ChangeLog

 2016-01-11  Tom de Vries  <tom@codesourcery.com>
 
+	PR tree-optimization/69109
+	* gcc.dg/autopar/pr69109-2.c: New test.
+	* gcc.dg/autopar/pr69109.c: New test.
+
+2016-01-11  Tom de Vries  <tom@codesourcery.com>
+
 	PR tree-optimization/69108
 	* gcc.dg/autopar/pr69108.c: New test.
 

gcc/testsuite/gcc.dg/autopar/pr69109-2.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2 -funswitch-loops" } */
+
+#include "../../gcc.c-torture/compile/pr32399.c"

gcc/testsuite/gcc.dg/autopar/pr69109.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2 -funswitch-loops" } */
+
+#include "../vect/unswitch-loops-pr26969.c"

gcc/tree-parloops.c

@@ -1769,6 +1769,10 @@ try_transform_to_exit_first_loop_alt (struct loop *loop,
   if (!gimple_seq_nondebug_singleton_p (bb_seq (loop->latch)))
     return false;
 
+  /* Check whether the latch contains no phis.  */
+  if (phi_nodes (loop->latch) != NULL)
+    return false;
+
   /* Check whether the latch contains the loop iv increment.  */
   edge back = single_succ_edge (loop->latch);
   edge exit = single_dom_exit (loop);