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[Bug tree-optimization/80155] [7 regression] Performance regression with code hoisting enabled
- From: "thopre01 at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 23 Mar 2017 11:15:42 +0000
- Subject: [Bug tree-optimization/80155] [7 regression] Performance regression with code hoisting enabled
- Auto-submitted: auto-generated
- References: <bug-80155-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80155
--- Comment #8 from Thomas Preud'homme <thopre01 at gcc dot gnu.org> ---
(In reply to rguenther@suse.de from comment #6 and #7)
>
> The testcase shows hardly profitable PRE which the patches should
> disable (I didn't verify the patches fix the testcase!)
The patch does not help for the testcase either (at least the Cortex-M7 one).
>
> If you're benchmarking at -O2 can you add -fpredictive-commoning? As
> said, the patch removes important loop optimizations from PRE.
Sorry, it does not make any difference (either for the benchmark or the
testcase).