tree-ssa-loop-manip.c (find_uses_to_rename): Do not scan the whole function when…

tree-ssa-loop-manip.c (find_uses_to_rename): Do not scan the whole function when there is nothing to do.

2013-03-18  Richard Biener  <rguenther@suse.de>

	* tree-ssa-loop-manip.c (find_uses_to_rename): Do not scan the
	whole function when there is nothing to do.
	* tree-ssa-loop.c (pass_vectorize): Remove TODO_update_ssa.
	* tree-vectorizer.c (vectorize_loops): Update virtual and
	loop-closed SSA once.
	* tree-vect-loop.c (vect_transform_loop): Do not update SSA here.

From-SVN: r196770

gcc/ChangeLog

 2013-03-18  Richard Biener  <rguenther@suse.de>
 
+	* tree-ssa-loop-manip.c (find_uses_to_rename): Do not scan the
+	whole function when there is nothing to do.
+	* tree-ssa-loop.c (pass_vectorize): Remove TODO_update_ssa.
+	* tree-vectorizer.c (vectorize_loops): Update virtual and
+	loop-closed SSA once.
+	* tree-vect-loop.c (vect_transform_loop): Do not update SSA here.
+
+2013-03-18  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/56113
 	* domwalk.c (bb_postorder): New global static.
 	(cmp_bb_postorder): New function.

gcc/tree-ssa-loop-manip.c

@@ -443,21 +443,12 @@ find_uses_to_rename (bitmap changed_bbs, bitmap *use_blocks, bitmap need_phis)
   unsigned index;
   bitmap_iterator bi;
 
-  /* ??? If CHANGED_BBS is empty we rewrite the whole function -- why?  */
-  if (changed_bbs && !bitmap_empty_p (changed_bbs))
-    {
-      EXECUTE_IF_SET_IN_BITMAP (changed_bbs, 0, index, bi)
-	{
-	  find_uses_to_rename_bb (BASIC_BLOCK (index), use_blocks, need_phis);
-	}
-    }
+  if (changed_bbs)
+    EXECUTE_IF_SET_IN_BITMAP (changed_bbs, 0, index, bi)
+      find_uses_to_rename_bb (BASIC_BLOCK (index), use_blocks, need_phis);
   else
-    {
-      FOR_EACH_BB (bb)
-	{
-	  find_uses_to_rename_bb (bb, use_blocks, need_phis);
-	}
-    }
+    FOR_EACH_BB (bb)
+      find_uses_to_rename_bb (bb, use_blocks, need_phis);
 }
 
 /* Rewrites the program into a loop closed ssa form -- i.e. inserts extra

gcc/tree-ssa-loop.c

@@ -245,8 +245,7 @@ struct gimple_opt_pass pass_vectorize =
   0,                                    /* properties_provided */
   0,                                    /* properties_destroyed */
   0,					/* todo_flags_start */
-  TODO_update_ssa
-    | TODO_ggc_collect			/* todo_flags_finish */
+  TODO_ggc_collect			/* todo_flags_finish */
  }
 };
 

gcc/tree-vect-loop.c

@@ -5773,11 +5773,6 @@ vect_transform_loop (loop_vec_info loop_vinfo)
 	 loop->nb_iterations_estimate = loop->nb_iterations_estimate - double_int_one;
     }
 
-  /* The memory tags and pointers in vectorized statements need to
-     have their SSA forms updated.  FIXME, why can't this be delayed
-     until all the loops have been transformed?  */
-  update_ssa (TODO_update_ssa);
-
   if (dump_enabled_p ())
     dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, vect_location, "LOOP VECTORIZED.");
   if (loop->inner && dump_enabled_p ())

gcc/tree-vectorizer.c

@@ -149,7 +149,16 @@ vectorize_loops (void)
 
   free_stmt_vec_info_vec ();
 
-  return num_vectorized_loops > 0 ? TODO_cleanup_cfg : 0;
+  if (num_vectorized_loops > 0)
+    {
+      /* If we vectorized any loop only virtual SSA form needs to be updated.
+	 ???  Also while we try hard to update loop-closed SSA form we fail
+	 to properly do this in some corner-cases (see PR56286).  */
+      rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa_only_virtuals);
+      return TODO_cleanup_cfg;
+    }
+
+  return 0;
 }