From 8d77f669e4cf7644bbd8274acba5587a4dd79957 Mon Sep 17 00:00:00 2001
From: kazu <kazu@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 22 Nov 2004 15:18:50 +0000
Subject: PR rtl-optimization/18599 * regrename.c
(copyprop_hardreg_forward): Speed up by putting BB_VISITED flags on
basic blocks as we process them.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@91016 138bc75d-0d04-0410-961f-82ee72b054a4
---
gcc/regrename.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
(limited to 'gcc/regrename.c')
diff --git a/gcc/regrename.c b/gcc/regrename.c
index 3153e5c353f..35f17a4d1d2 100644
--- a/gcc/regrename.c
+++ b/gcc/regrename.c
@@ -1745,24 +1745,31 @@ copyprop_hardreg_forward (void)
{
struct value_data *all_vd;
bool need_refresh;
- basic_block bb, bbp = 0;
+ basic_block bb;
need_refresh = false;
all_vd = xmalloc (sizeof (struct value_data) * last_basic_block);
+ /* Clear all BB_VISITED flags. We use BB_VISITED flags to indicate
+ whether we have processed a given basic block or not. Note that
+ we never put BB_VISITED flag on ENTRY_BLOCK_PTR throughout this
+ function because we want to call init_value_data for all
+ successors of ENTRY_BLOCK_PTR. */
+ FOR_ALL_BB (bb)
+ bb->flags &= ~BB_VISITED;
+
FOR_EACH_BB (bb)
{
+ bb->flags |= BB_VISITED;
+
/* If a block has a single predecessor, that we've already
processed, begin with the value data that was live at
the end of the predecessor block. */
/* ??? Ought to use more intelligent queuing of blocks. */
- if (EDGE_COUNT (bb->preds) == 1)
- for (bbp = bb; bbp && bbp != EDGE_PRED (bb, 0)->src; bbp = bbp->prev_bb);
if (EDGE_COUNT (bb->preds) == 1
- && ! (EDGE_PRED (bb, 0)->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
- && EDGE_PRED (bb, 0)->src != ENTRY_BLOCK_PTR
- && bbp)
+ && ((EDGE_PRED (bb, 0)->src->flags & BB_VISITED) != 0)
+ && ! (EDGE_PRED (bb, 0)->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)))
all_vd[bb->index] = all_vd[EDGE_PRED (bb, 0)->src->index];
else
init_value_data (all_vd + bb->index);
@@ -1771,6 +1778,12 @@ copyprop_hardreg_forward (void)
need_refresh = true;
}
+ /* Clear BB_VISITED flag on each basic block. We do not need to
+ clear the one on ENTRY_BLOCK_PTR because it's already cleared
+ above. */
+ FOR_EACH_BB (bb)
+ bb->flags &= ~BB_VISITED;
+
if (need_refresh)
{
if (dump_file)
--
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