diff options
| author | Richard Biener <rguenther@suse.de> | 2022-09-01 13:28:08 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-09-01 15:06:28 +0200 |
| commit | 47e15513c9e581ef04ad25fb0d561a45d345edd1 (patch) | |
| tree | d8af15a8e1c5afdc3cf7fd873e1874fcfab42d57 | |
| parent | e75398ac9f06d67cffe495a150e2b27064f3971d (diff) | |
| download | gcc-47e15513c9e581ef04ad25fb0d561a45d345edd1.zip gcc-47e15513c9e581ef04ad25fb0d561a45d345edd1.tar.gz gcc-47e15513c9e581ef04ad25fb0d561a45d345edd1.tar.bz2 | |
Remove cycle checking from compute_control_dep_chain
Now that we have DFS_BACK_EDGE marks we can simply avoid walking
those instead of repeatedly looking for a cycle on the current chain.
* gimple-predicate-analysis.cc (compute_control_dep_chain):
Remove cycle detection, instead avoid walking backedges.
| -rw-r--r-- | gcc/gimple-predicate-analysis.cc | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/gcc/gimple-predicate-analysis.cc b/gcc/gimple-predicate-analysis.cc index 2982268..a754ff0 100644 --- a/gcc/gimple-predicate-analysis.cc +++ b/gcc/gimple-predicate-analysis.cc @@ -1035,18 +1035,6 @@ compute_control_dep_chain (basic_block dom_bb, const_basic_block dep_bb, fprintf (dump_file, "chain length exceeds 5: %u\n", cur_chain_len); } - for (unsigned i = 0; i < cur_chain_len; i++) - { - edge e = cur_cd_chain[i]; - /* Cycle detected. */ - if (e->src == dom_bb) - { - if (dump_file) - fprintf (dump_file, "cycle detected\n"); - return false; - } - } - if (DEBUG_PREDICATE_ANALYZER && dump_file) fprintf (dump_file, "%*s%s (dom_bb = %u, dep_bb = %u, cd_chains = { %s }, ...)\n", @@ -1061,7 +1049,7 @@ compute_control_dep_chain (basic_block dom_bb, const_basic_block dep_bb, FOR_EACH_EDGE (e, ei, dom_bb->succs) { int post_dom_check = 0; - if (e->flags & (EDGE_FAKE | EDGE_ABNORMAL)) + if (e->flags & (EDGE_FAKE | EDGE_ABNORMAL | EDGE_DFS_BACK)) continue; basic_block cd_bb = e->dest; @@ -1110,6 +1098,12 @@ compute_control_dep_chain (basic_block dom_bb, const_basic_block dep_bb, break; } + /* The post-dominator walk will reach a backedge only + from a forwarder, otherwise it should choose to exit + the SCC. */ + if (single_succ_p (cd_bb) + && single_succ_edge (cd_bb)->flags & EDGE_DFS_BACK) + break; cd_bb = get_immediate_dominator (CDI_POST_DOMINATORS, cd_bb); post_dom_check++; if (cd_bb == EXIT_BLOCK_PTR_FOR_FN (cfun) |