re PR tree-optimization/58554 (Revision 202619 causes runtime failure in CPU2006…

re PR tree-optimization/58554 (Revision 202619 causes runtime failure in CPU2006 benchmark 445.gobmk)

2013-09-30  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58554
	* tree-loop-distribution.c (classify_partition): Require unconditionally
	executed stores for memcpy and memset recognition.
	(tree_loop_distribution): Calculate dominance info.

	* gcc.dg/torture/pr58554.c: New testcase.

From-SVN: r203031

gcc/ChangeLog

+2013-09-30  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58554
+	* tree-loop-distribution.c (classify_partition): Require unconditionally
+	executed stores for memcpy and memset recognition.
+	(tree_loop_distribution): Calculate dominance info.
+
 2013-09-30  Venkataramanan Kumar  <venkataramanan.kumar@linaro.org>
 
 	* config/aarch64/aarch64.h (MCOUNT_NAME): Define.

gcc/testsuite/ChangeLog

+2013-09-30  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58554
+	* gcc.dg/torture/pr58554.c: New testcase.
+
 2013-09-30  Simon Cook  <simon.cook@embecosm.com>
 	    Joern Rennecke  <joern.rennecke@embecosm.com>
 

gcc/testsuite/gcc.dg/torture/pr58554.c

+/* { dg-do run } */
+
+extern void abort (void);
+void __attribute__((noinline,noclone))
+clear_board(unsigned char *board, int board_size)
+{
+  int k;
+  for (k = 0; k < 421; k++)
+    if (k < board_size )
+      board[k] = 3;
+}
+int main()
+{
+  unsigned char board[421];
+  board[420] = 1;
+  clear_board (board, 420);
+  if (board[420] != 1)
+    abort ();
+  return 0;
+}

gcc/tree-loop-distribution.c

@@ -1206,7 +1206,9 @@ classify_partition (loop_p loop, struct graph *rdg, partition_t partition)
 	  && !SSA_NAME_IS_DEFAULT_DEF (rhs)
 	  && flow_bb_inside_loop_p (loop, gimple_bb (SSA_NAME_DEF_STMT (rhs))))
 	return;
-      if (!adjacent_dr_p (single_store))
+      if (!adjacent_dr_p (single_store)
+	  || !dominated_by_p (CDI_DOMINATORS,
+			      loop->latch, gimple_bb (stmt)))
 	return;
       partition->kind = PKIND_MEMSET;
       partition->main_dr = single_store;
@@ -1222,7 +1224,9 @@ classify_partition (loop_p loop, struct graph *rdg, partition_t partition)
       if (!adjacent_dr_p (single_store)
 	  || !adjacent_dr_p (single_load)
 	  || !operand_equal_p (DR_STEP (single_store),
-			       DR_STEP (single_load), 0))
+			       DR_STEP (single_load), 0)
+	  || !dominated_by_p (CDI_DOMINATORS,
+			      loop->latch, gimple_bb (store)))
 	return;
       /* Now check that if there is a dependence this dependence is
          of a suitable form for memmove.  */
@@ -1719,6 +1723,7 @@ out:
 	{
 	  if (!cd)
 	    {
+	      calculate_dominance_info (CDI_DOMINATORS);
 	      calculate_dominance_info (CDI_POST_DOMINATORS);
 	      cd = new control_dependences (create_edge_list ());
 	      free_dominance_info (CDI_POST_DOMINATORS);