Since the worklist was never added to and the anlysis part can benifit
from the work part, we can combine the analayis part with the work part.
This should get a small speedup for this pass
Looking into the history here, remove_forwarder_block used to add to the
worklist
but remove_forwarder_block_with_phi never did.
This is the first step in moving part of the functionality of mergephi into
cfgcleanup.
gcc/ChangeLog:
* tree-cfgcleanup.cc (pass_merge_phi::execute): Remove worklist.
Signed-off-by: Andrew Pinski <[email protected]>
---
gcc/tree-cfgcleanup.cc | 35 ++++++++++++-----------------------
1 file changed, 12 insertions(+), 23 deletions(-)
diff --git a/gcc/tree-cfgcleanup.cc b/gcc/tree-cfgcleanup.cc
index 58e8af5efcf..2e613df6855 100644
--- a/gcc/tree-cfgcleanup.cc
+++ b/gcc/tree-cfgcleanup.cc
@@ -1456,16 +1456,17 @@ public:
unsigned int
pass_merge_phi::execute (function *fun)
{
- basic_block *worklist = XNEWVEC (basic_block, n_basic_blocks_for_fn (fun));
- basic_block *current = worklist;
- basic_block bb;
-
calculate_dominance_info (CDI_DOMINATORS);
/* Find all PHI nodes that we may be able to merge. */
- FOR_EACH_BB_FN (bb, fun)
+ bool changed = false;
+ unsigned n = last_basic_block_for_fn (fun);
+ for (unsigned i = NUM_FIXED_BLOCKS; i < n; i++)
{
basic_block dest;
+ basic_block bb = BASIC_BLOCK_FOR_FN (fun, i);
+ if (!bb)
+ continue;
/* Look for a forwarder block with PHI nodes. */
if (!tree_forwarder_block_p (bb, true))
@@ -1481,14 +1482,10 @@ pass_merge_phi::execute (function *fun)
|| bb_has_abnormal_pred (bb))
continue;
- if (!dominated_by_p (CDI_DOMINATORS, dest, bb))
- {
- /* If BB does not dominate DEST, then the PHI nodes at
- DEST must be the only users of the results of the PHI
- nodes at BB. */
- *current++ = bb;
- }
- else
+ /* If BB does not dominate DEST, then the PHI nodes at
+ DEST must be the only users of the results of the PHI
+ nodes at BB. So only check when BB dominates dest. */
+ if (dominated_by_p (CDI_DOMINATORS, dest, bb))
{
gphi_iterator gsi;
unsigned int dest_idx = single_succ_edge (bb)->dest_idx;
@@ -1521,19 +1518,11 @@ pass_merge_phi::execute (function *fun)
/* If the loop above iterated through all the PHI nodes
in BB, then we can merge the PHIs from BB into DEST. */
- if (gsi_end_p (gsi))
- *current++ = bb;
+ if (!gsi_end_p (gsi))
+ continue;
}
- }
-
- /* Now let's drain WORKLIST. */
- bool changed = false;
- while (current != worklist)
- {
- bb = *--current;
changed |= remove_forwarder_block_with_phi (bb);
}
- free (worklist);
/* Removing forwarder blocks can cause formerly irreducible loops
to become reducible if we merged two entry blocks. */
--
2.43.0
