https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107409

--- Comment #9 from Rama Malladi <rvmallad at amazon dot com> ---
(In reply to Martin Liška from comment #3)
> Can you please share perf-profile before and after the revision?
> 
> Note I can't see it for Altra aarch64 CPU:
> https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=633.477.0&plot.
> 1=683.477.0&plot.2=664.477.0&plot.3=648.477.0&plot.4=618.477.0&plot.5=605.
> 477.0&plot.6=759.477.0&plot.7=584.477.0&
> 
> However, there are huge changes in between GCC 6/7 and a newer releases.
> Note the benchmark is pretty small and very sensitive to instruction caches.

Hi, I got IPC data for baseline version of compiler and with this patch
reverted.

This is on Graviton3 processor machine, executing 1-copy rate run of 519.lbm_r.

Baseline: Compiler commit ID: f896c13489d22b30d01257bc8316ab97b3359d1c
Cycles:            148,489,372,938
Instructions:      382,748,379,257
IPC:               2.58

Baseline with code change in a9a4edf0e71bbac9f1b5dcecdcf9250111d16889 reverted.

$ git diff gcc/tree-cfg.cc
diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc
index d982988048f..736432713fe 100644
--- a/gcc/tree-cfg.cc
+++ b/gcc/tree-cfg.cc
@@ -9984,7 +9984,7 @@ execute_fixup_cfg (void)
     }
   if (scale)
     {
-      update_max_bb_count ();
+//      update_max_bb_count ();
       compute_function_frequency ();
     }

Cycles:            140,937,228,769
Instructions:      368,881,714,982
IPC:               2.62

>From the above, I do see the instructions executed are higher for the baseline
compiler code-gen vs. the one with patch reverted. Can you please look into the
code-gen and let me know if you find some perf opportunity with this patch
revert? Thank you.

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