re PR tree-optimization/68060 (ICE on valid code at -O3 on x86_64-linux-gnu in…

re PR tree-optimization/68060 (ICE on valid code at -O3 on x86_64-linux-gnu in vect_get_vec_def_for_operand, at tree-vect-stmts.c:1413)

2016-01-14  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68060
	* tree-vect-loop.c (vect_is_simple_reduction): Check the
	outer loop reduction is only used in the inner loop before
	detecting a double reduction.

	* gcc.dg/torture/pr68060-1.c: New testcase.
	* gcc.dg/torture/pr68060-2.c: Likewise.

From-SVN: r232367

gcc/ChangeLog

+2016-01-14  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68060
+	* tree-vect-loop.c (vect_is_simple_reduction): Check the
+	outer loop reduction is only used in the inner loop before
+	detecting a double reduction.
+
 2016-01-14  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/68269

gcc/testsuite/ChangeLog

+2016-01-14  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68060
+	* gcc.dg/torture/pr68060-1.c: New testcase.
+	* gcc.dg/torture/pr68060-2.c: Likewise.
+
 2016-01-14  Nick Clifton  <nickc@redhat.com>
 
 	* lib/target-supports.exp

gcc/testsuite/gcc.dg/torture/pr68060-1.c

+/* { dg-do compile } */
+
+int a, b, c;
+
+int
+main ()
+{
+  for (; c; c++)
+    for (a = 0; a < 4; a++)
+      {
+	c &= 5;
+	for (b = 0; b < 2; b++)
+	  c |= 1;
+      }
+  return 0; 
+}

gcc/testsuite/gcc.dg/torture/pr68060-2.c

+/* { dg-do compile } */
+
+void fn2 ();
+
+int a, b, c;
+
+void fn1()
+{
+  for (;;) {
+      int *d;
+      fn2();
+      c = 0;
+      for (; c <= 3; c++) {
+	  *d ^= 9;
+	  b = 0;
+	  for (; b <= 3; b++)
+	    *d ^= a;
+      }
+  }
+}

gcc/tree-vect-loop.c

@@ -2591,7 +2591,7 @@ vect_is_simple_reduction (loop_vec_info loop_info, gimple *phi,
   struct loop *vect_loop = LOOP_VINFO_LOOP (loop_info);
   edge latch_e = loop_latch_edge (loop);
   tree loop_arg = PHI_ARG_DEF_FROM_EDGE (phi, latch_e);
-  gimple *def_stmt, *def1 = NULL, *def2 = NULL;
+  gimple *def_stmt, *def1 = NULL, *def2 = NULL, *phi_use_stmt = NULL;
   enum tree_code orig_code, code;
   tree op1, op2, op3 = NULL_TREE, op4 = NULL_TREE;
   tree type;
@@ -2640,6 +2640,8 @@ vect_is_simple_reduction (loop_vec_info loop_info, gimple *phi,
 			     "reduction used in loop.\n");
           return NULL;
         }
+
+      phi_use_stmt = use_stmt;
     }
 
   if (TREE_CODE (loop_arg) != SSA_NAME)
@@ -2722,7 +2724,8 @@ vect_is_simple_reduction (loop_vec_info loop_info, gimple *phi,
 	  && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt))
           && loop->inner
           && flow_bb_inside_loop_p (loop->inner, gimple_bb (def1))
-          && is_gimple_assign (def1))
+          && is_gimple_assign (def1)
+	  && flow_bb_inside_loop_p (loop->inner, gimple_bb (phi_use_stmt)))
         {
           if (dump_enabled_p ())
             report_vect_op (MSG_NOTE, def_stmt,