[PATCH] tree-optimization/103990 - fix CFG cleanup regression from PRE change

[Richard Biener via Gcc-patches]

This adjusts the CFG cleanup flow back to what it was before the
last change which fixes the observed regression of 541.leela_r with
LTO and FDO.

Boostrapped on x86_64-unknown-linux-gnu, testing in progress.

2022-01-12  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/103990
        * tree-pass.h (tail_merge_optimize): Drop unused argument.
        * tree-ssa-tail-merge.c (tail_merge_optimize): Likewise.
        * tree-ssa-pre.c (pass_pre::execute): Retain TODO_cleanup_cfg
        and adjust call to tail_merge_optimize.
---
 gcc/tree-pass.h           | 2 +-
 gcc/tree-ssa-pre.c        | 6 ++----
 gcc/tree-ssa-tail-merge.c | 4 ++--
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index 36097cf2736..606d1d60b85 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -412,7 +412,7 @@ extern gimple_opt_pass *make_pass_early_thread_jumps 
(gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_split_crit_edges (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_laddress (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_pre (gcc::context *ctxt);
-extern unsigned int tail_merge_optimize (unsigned int, bool);
+extern unsigned int tail_merge_optimize (bool);
 extern gimple_opt_pass *make_pass_profile (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_strip_predict_hints (gcc::context *ctxt);
 extern gimple_opt_pass *make_pass_lower_complex_O0 (gcc::context *ctxt);
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index ab24fa98a1f..5113256802e 100644
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -4442,7 +4442,6 @@ pass_pre::execute (function *fun)
   if (todo & TODO_cleanup_cfg)
     {
       cleanup_tree_cfg ();
-      todo &= ~TODO_cleanup_cfg;
       need_crit_edge_split = true;
     }
 
@@ -4458,9 +4457,8 @@ pass_pre::execute (function *fun)
      It should either:
      - call merge_blocks after each tail merge iteration
      - call merge_blocks after all tail merge iterations
-     - mark TODO_cleanup_cfg when necessary
-     - share the cfg cleanup with fini_pre.  */
-  todo |= tail_merge_optimize (todo, need_crit_edge_split);
+     - mark TODO_cleanup_cfg when necessary.  */
+  todo |= tail_merge_optimize (need_crit_edge_split);
 
   free_rpo_vn ();
 
diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c
index fd333800f0f..8e1ea1a982e 100644
--- a/gcc/tree-ssa-tail-merge.c
+++ b/gcc/tree-ssa-tail-merge.c
@@ -1724,7 +1724,7 @@ update_debug_stmts (void)
 /* Runs tail merge optimization.  */
 
 unsigned int
-tail_merge_optimize (unsigned int todo, bool need_crit_edge_split)
+tail_merge_optimize (bool need_crit_edge_split)
 {
   int nr_bbs_removed_total = 0;
   int nr_bbs_removed;
@@ -1814,5 +1814,5 @@ tail_merge_optimize (unsigned int todo, bool 
need_crit_edge_split)
 
   timevar_pop (TV_TREE_TAIL_MERGE);
 
-  return todo;
+  return 0;
 }
-- 
2.31.1