pr45241 give up dot_prod pattern searching if stmt is outside the loop.

	* tree-vect-patterns.c (vect_recog_dot_prod_pattern): Give
	up dot_prod pattern searching if a stmt is outside the loop.

	* gcc.dg/vect/no-tree-pre-pr45241.c: New.

From-SVN: r163207

gcc/ChangeLog

+2010-08-12  Changpeng Fang  <changpeng.fang@amd.com>
+
+	* tree-vect-patterns.c (vect_recog_dot_prod_pattern): Give
+	up dot_prod pattern searching if a stmt is outside the loop.
+
 2010-08-12  H.J. Lu  <hongjiu.lu@intel.com>
 	    Uros Bizjak  <ubizjak@gmail.com>
 

gcc/testsuite/ChangeLog

+2010-08-12  Changpeng Fang  <changpeng.fang@amd.com>
+
+	PR tree-optimization/45241
+	* gcc.dg/vect/no-tree-pre-pr45241.c: New test.
+
 2010-08-12  Uros Bizjak  <ubizjak@gmail.com>
 
 	* gcc.target/i386/pr40906-1.c: Add -fno-asynchronous-unwind-tables

gcc/testsuite/gcc.dg/vect/no-tree-pre-pr45241.c

+/* PR tree-optimization/45241 */
+/* { dg-do compile } */
+/* { dg-options "-ftree-vectorize" } */
+
+int
+foo (short x)
+{
+  short i, y;
+  int sum;
+
+  for (i = 0; i < x; i++)
+    y = x * i;
+
+  for (i = x; i > 0; i--)
+    sum += y;
+
+  return sum;
+}
+
+/* { dg-final { cleanup-tree-dump "vect" } } */

gcc/tree-vect-patterns.c

@@ -255,6 +255,11 @@ vect_recog_dot_prod_pattern (gimple last_stmt, tree *type_in, tree *type_out)
 
   prod_type = half_type;
   stmt = SSA_NAME_DEF_STMT (oprnd0);
+
+  /* It could not be the dot_prod pattern if the stmt is outside the loop.  */
+  if (!flow_bb_inside_loop_p (loop, gimple_bb (stmt)))
+    return NULL;
+
   /* FORNOW.  Can continue analyzing the def-use chain when this stmt in a phi
      inside the loop (in case we are analyzing an outer-loop).  */
   if (!is_gimple_assign (stmt))