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From: "fkastl at suse dot cz" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/112697] New: [14 Regression] 30-40% exec time
 regression of 433.milc on zen2
Date: Fri, 24 Nov 2023 09:03:48 +0000
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X-Bugzilla-Product: gcc
X-Bugzilla-Component: middle-end
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: missed-optimization, needs-bisection
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D112697

            Bug ID: 112697
           Summary: [14 Regression] 30-40% exec time regression of
                    433.milc on zen2
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, needs-bisection
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fkastl at suse dot cz
  Target Milestone: ---
              Host: x86_64-linux
            Target: x86_64-linux

Between commits

g:0c305f3dec9a992dd775a3b9607b7b1e8c051859
g:7f974c5fd4f59a9d8dd20c49a0e2909cb290f4b4

there's a 30-40% slowdown of the 433.milc 2006SPEC benchmark as seen here:

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=3D292.70.0

It's 40% here and I also measured the slowdown on another zen2 machine where
the difference was 30%.

Compile options:

-g -O2 -flto=3D128=