Add -ftree-loop-distribute-patterns enabled at -O3.

[pf3gnuchains/gcc-fork.git] / gcc / tree-loop-distribution.c

diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c
index 099a7fe..5905406 100644 (file)
--- a/gcc/tree-loop-distribution.c
+++ b/gcc/tree-loop-distribution.c
@@ -1184,18 +1184,36 @@ tree_loop_distribution (void)
     {
       VEC (gimple, heap) *work_list = VEC_alloc (gimple, heap, 3);
 
-      /* With the following working list, we're asking distribute_loop
-        to separate the stores of the loop: when dependences allow,
-        it will end on having one store per loop.  */
-      stores_from_loop (loop, &work_list);
-
-      /* A simple heuristic for cache locality is to not split stores
-        to the same array.  Without this call, an unrolled loop would
-        be split into as many loops as unroll factor, each loop
-        storing in the same array.  */
-      remove_similar_memory_refs (&work_list);
-
-      nb_generated_loops = distribute_loop (loop, work_list);
+      /* If both flag_tree_loop_distribute_patterns and
+        flag_tree_loop_distribution are set, then only
+        distribute_patterns is executed.  */
+      if (flag_tree_loop_distribute_patterns)
+       {
+         /* With the following working list, we're asking
+            distribute_loop to separate from the rest of the loop the
+            stores of the form "A[i] = 0".  */
+         stores_zero_from_loop (loop, &work_list);
+
+         /* Do nothing if there are no patterns to be distributed.  */
+         if (VEC_length (gimple, work_list) > 0)
+           nb_generated_loops = distribute_loop (loop, work_list);
+       }
+      else if (flag_tree_loop_distribution)
+       {
+         /* With the following working list, we're asking
+            distribute_loop to separate the stores of the loop: when
+            dependences allow, it will end on having one store per
+            loop.  */
+         stores_from_loop (loop, &work_list);
+
+         /* A simple heuristic for cache locality is to not split
+            stores to the same array.  Without this call, an unrolled
+            loop would be split into as many loops as unroll factor,
+            each loop storing in the same array.  */
+         remove_similar_memory_refs (&work_list);
+
+         nb_generated_loops = distribute_loop (loop, work_list);
+       }
 
       if (dump_file && (dump_flags & TDF_DETAILS))
        {
@@ -1217,7 +1235,8 @@ tree_loop_distribution (void)
 static bool
 gate_tree_loop_distribution (void)
 {
-  return flag_tree_loop_distribution != 0;
+  return flag_tree_loop_distribution
+    || flag_tree_loop_distribute_patterns;
 }
 
 struct gimple_opt_pass pass_loop_distribution =