[patch] tree-outof-ssa.c: VECify stmt_list.

[Kazu Hirata <kazu at cs dot umass dot edu>]

Hi,

Attached is a patch to VECify stmt_list.

Andrew, we have several options here.

o Go with the simple VARRAY -> VEC(tree,gc)* option.  (This is what
  the patch below does.)

o Allocate and free these work areas on heap in analyze_edges_for_bb
  since the use of the memory does not "escape" the function.

o Allocate and free these work areas in perform_edge_inserts so that
  you won't have to allocate and free them every time
  analyze_edges_for_bb is called.

I would prefer the second and third option, but I am asking you
because you seem to want to reuse the memory from previous call to
analyze_edge_for_bb.  Well, reusing the memory may be the only
reasonable thing you can do with VARRAY on GC. :-)

Tested on i686-pc-linux-gnu.  Thoughts?  Preference?

Kazu Hirata

2005-05-03  Kazu Hirata  <kazu@cs.umass.edu>

	* tree-outof-ssa.c (stmt_list, analyze_edges_for_bb): Use VEC
	instead of VARRAY.

Index: tree-outof-ssa.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-outof-ssa.c,v
retrieving revision 2.56
diff -u -d -p -r2.56 tree-outof-ssa.c
--- tree-outof-ssa.c	22 Apr 2005 10:56:55 -0000	2.56
+++ tree-outof-ssa.c	2 May 2005 00:06:53 -0000
@@ -1951,7 +1951,7 @@ rewrite_trees (var_map map, tree *values
 /* These are the local work structures used to determine the best place to 
    insert the copies that were placed on edges by the SSA->normal pass..  */
 static varray_type edge_leader = NULL;
-static varray_type GTY(()) stmt_list = NULL;
+static GTY(()) VEC(tree,gc) *stmt_list = NULL;
 static bitmap leader_has_match = NULL;
 static edge leader_match = NULL;
 
@@ -2096,14 +2096,14 @@ analyze_edges_for_bb (basic_block bb, FI
   if (edge_leader == NULL)
     {
       VARRAY_EDGE_INIT (edge_leader, 25, "edge_leader");
-      VARRAY_TREE_INIT (stmt_list, 25, "stmt_list");
+      stmt_list = VEC_alloc (tree, gc, 25);
       leader_has_match = BITMAP_ALLOC (NULL);
     }
   else
     {
 #ifdef ENABLE_CHECKING
       gcc_assert (VARRAY_ACTIVE_SIZE (edge_leader) == 0);
-      gcc_assert (VARRAY_ACTIVE_SIZE (stmt_list) == 0);
+      gcc_assert (VEC_length (tree, stmt_list) == 0);
       gcc_assert (bitmap_empty_p (leader_has_match));
 #endif
     }
@@ -2138,7 +2138,7 @@ analyze_edges_for_bb (basic_block bb, FI
 	  if (!found)
 	    {
 	      VARRAY_PUSH_EDGE (edge_leader, e);
-	      VARRAY_PUSH_TREE (stmt_list, PENDING_STMT (e));
+	      VEC_safe_push (tree, gc, stmt_list, PENDING_STMT (e));
 	    }
 	}
      }
@@ -2149,7 +2149,7 @@ analyze_edges_for_bb (basic_block bb, FI
       for (x = 0; x < VARRAY_ACTIVE_SIZE (edge_leader); x++)
 	bsi_commit_one_edge_insert (VARRAY_EDGE (edge_leader, x), NULL);
       VARRAY_POP_ALL (edge_leader);
-      VARRAY_POP_ALL (stmt_list);
+      VEC_truncate (tree, stmt_list, 0);
       bitmap_clear (leader_has_match);
       return;
     }
@@ -2177,7 +2177,7 @@ analyze_edges_for_bb (basic_block bb, FI
 	   and use the saved stmt list.  */
 	PENDING_STMT (leader_edge) = NULL;
 	leader_edge->aux = leader_edge;
-	curr_stmt_list = VARRAY_TREE (stmt_list, x);
+	curr_stmt_list = VEC_index (tree, stmt_list, x);
 
         new_edge = make_forwarder_block (leader_edge->dest, same_stmt_list_p, 
 					 NULL);
@@ -2207,14 +2207,14 @@ analyze_edges_for_bb (basic_block bb, FI
     else
       {
         e = VARRAY_EDGE (edge_leader, x);
-	PENDING_STMT (e) = VARRAY_TREE (stmt_list, x);
+	PENDING_STMT (e) = VEC_index (tree, stmt_list, x);
 	bsi_commit_one_edge_insert (e, NULL);
       }
 
    
   /* Clear the working data structures.  */
   VARRAY_POP_ALL (edge_leader);
-  VARRAY_POP_ALL (stmt_list);
+  VEC_truncate (tree, stmt_list, 0);
   bitmap_clear (leader_has_match);
 }