2001-08-28 Daniel Berlin <dan@cgsoftware.com>

	* df.h (struct df): Add rts_order variable.

	* df.c (df_visit_next_rts): New function.
	(df_visit_next): Renamed to df_visit_next_rc
	(df_analyse_1): Allocate/compute/free rts_order as well.
	(df_rd_global_compute): Use df_visit_next_rc instead of
	df_visit_next.
	(df_ru_global_compute): Use df_visit_next_rts instead of
	df_visit_next.

	* flow.c (flow_reverse_top_sort_order_compute): New function.

	* basic-block.h: Add prototype.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@45246 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 25 insertions, 6 deletions

diff --git a/gcc/df.c b/gcc/df.c
index 6f1b18f952e..177da105126 100644
--- a/gcc/df.c
+++ b/gcc/df.c
@@ -238,7 +238,8 @@ static void df_insn_refs_record PARAMS((struct df *, basic_block, rtx));
 static void df_bb_refs_record PARAMS((struct df *, basic_block));
 static void df_refs_record PARAMS((struct df *, bitmap));
 
-static int df_visit_next PARAMS ((struct df *, sbitmap));
+static int df_visit_next_rc PARAMS ((struct df *, sbitmap));
+static int df_visit_next_rts PARAMS ((struct df *, sbitmap));
 static void df_bb_reg_def_chain_create PARAMS((struct df *, basic_block));
 static void df_reg_def_chain_create PARAMS((struct df *, bitmap));
 static void df_bb_reg_use_chain_create PARAMS((struct df *, basic_block));
@@ -1600,11 +1601,11 @@ df_ud_chain_create (df, blocks)
 }
 
 
-/* Use depth first order, and the worklist, to figure out what block
+/* Use reverse completion order, and the worklist, to figure out what block
    to look at next.  */
 
 static int
-df_visit_next (df, blocks)
+df_visit_next_rc (df, blocks)
      struct df *df ATTRIBUTE_UNUSED;
      sbitmap blocks;
 {
@@ -1615,6 +1616,22 @@ df_visit_next (df, blocks)
   return sbitmap_first_set_bit (blocks);
 }
 
+/* Use reverse topsort order, and the worklist, to figure out what block
+   to look at next.  */
+
+static int
+df_visit_next_rts (df, blocks)
+     struct df *df ATTRIBUTE_UNUSED;
+     sbitmap blocks;
+{
+  int i=0;
+  for (i = 0; i < n_basic_blocks; i++)
+    if (TEST_BIT (blocks, df->rts_order[i]))
+      return df->rts_order[i];
+  return sbitmap_first_set_bit (blocks);
+}
+
+
 /* Calculate reaching defs for each basic block in BLOCKS, i.e., the
    defs that are live at the start of a basic block.  */
 static void
@@ -1644,7 +1661,7 @@ df_rd_global_compute (df, blocks)
       bitmap_copy (bb_info->rd_out, bb_info->rd_gen);
     });
   
-  while ((i = df_visit_next (df, worklist)) >= 0)
+  while ((i = df_visit_next_rc (df, worklist)) >= 0)
     {
       struct bb_info *bb_info;
       edge e;
@@ -1722,7 +1739,7 @@ df_ru_global_compute (df, blocks)
     });
 
 
-  while ((i = df_visit_next (df, worklist)) >= 0)
+  while ((i = df_visit_next_rts (df, worklist)) >= 0)
     {
       struct bb_info *bb_info;
       edge e;
@@ -2221,9 +2238,10 @@ df_analyse_1 (df, blocks, flags, update)
 
   df->dfs_order = xmalloc (sizeof(int) * n_basic_blocks);
   df->rc_order = xmalloc (sizeof(int) * n_basic_blocks);
+  df->rts_order = xmalloc (sizeof(int) * n_basic_blocks);
   
   flow_depth_first_order_compute (df->dfs_order, df->rc_order);
-
+  flow_reverse_top_sort_order_compute (df->rts_order);
   if (aflags & DF_RD)
     {
       /* Compute the sets of gens and kills for the defs of each bb.  */
@@ -2280,6 +2298,7 @@ df_analyse_1 (df, blocks, flags, update)
     } 
   free (df->dfs_order);
   free (df->rc_order);
+  free (df->rts_order);
 }