Handle case that outer phi res is not used in a phi in gather_scalar_reductions

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.dg/autopar/pr69108.c: New test.

From-SVN: r232211

gcc/ChangeLog

+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.
+
 2016-01-11  Yury Gribov  <y.gribov@samsung.com>
 
 	PR 67425

gcc/testsuite/ChangeLog

+2016-01-11  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/69108
+	* gcc.dg/autopar/pr69108.c: New test.
+
 2016-01-10  Patrick Palka  <ppalka@gcc.gnu.org>
 
 	PR c++/69029

gcc/testsuite/gcc.dg/autopar/pr69108.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-parallelize-loops=2" } */
+
+#include "../graphite/interchange-2.c"

gcc/tree-parloops.c

@@ -2474,6 +2474,8 @@ gather_scalar_reductions (loop_p loop, reduction_info_table_type *reduction_list
 	  gimple *inner_stmt;
 	  bool single_use_p = single_imm_use (res, &use_p, &inner_stmt);
 	  gcc_assert (single_use_p);
+	  if (gimple_code (inner_stmt) != GIMPLE_PHI)
+	    continue;
 	  gphi *inner_phi = as_a <gphi *> (inner_stmt);
 	  if (simple_iv (loop->inner, loop->inner, PHI_RESULT (inner_phi),
 			 &iv, true))