Handle NULL def in build_cross_bb_scalars_def

2016-05-07  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/70956
	* graphite-scop-detection.c (build_cross_bb_scalars_def): Handle NULL
	def.

	* gcc.dg/graphite/pr70956.c: New test.

From-SVN: r235994

gcc/ChangeLog

+2016-05-07  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/70956
+	* graphite-scop-detection.c (build_cross_bb_scalars_def): Handle NULL
+	def.
+
 2016-05-07  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	* config/sh/sh-protos.h (sh_cbranch_distance): Declare new function.

gcc/graphite-scop-detection.c

@@ -1722,8 +1722,7 @@ static void
 build_cross_bb_scalars_def (scop_p scop, tree def, basic_block def_bb,
 			     vec<tree> *writes)
 {
-  gcc_assert (def);
-  if (!is_gimple_reg (def))
+  if (!def || !is_gimple_reg (def))
     return;
 
   /* Do not gather scalar variables that can be analyzed by SCEV as they can be

gcc/testsuite/ChangeLog

+2016-05-07  Tom de Vries  <tom@codesourcery.com>
+
+	PR tree-optimization/70956
+	* gcc.dg/graphite/pr70956.c: New test.
+
 2016-05-06  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/70941

gcc/testsuite/gcc.dg/graphite/pr70956.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fgraphite-identity" } */
+
+#include "../tree-ssa/vrp66.c"