[Bug target/118125] New: [15 Regression] 7-16% slowdown of 510.parest_r on x86-64(-v3) since r15-6110-g92e0e0f8177530

[pheeck at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118125

            Bug ID: 118125
           Summary: [15 Regression] 7-16% slowdown of 510.parest_r on
                    x86-64(-v3) since r15-6110-g92e0e0f8177530
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pheeck at gcc dot gnu.org
                CC: jamborm at gcc dot gnu.org
            Blocks: 26163
  Target Milestone: ---
              Host: x86_64-linux
            Target: x86_64-linux

As seen here

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=1118.457.0
https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=959.457.0
https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=475.457.0
https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=287.457.0

there was a 7-16% exec time slowdown of the 510.parest_r SPEC 2017 benchmark
when run with -Ofast -flto -march=x86-64-v3 or -march=native on zen{2,3,4}
machines.

I've bisected this to

r15-6110-g92e0e0f8177530

Author:     Martin Jambor <mjambor@suse.cz>
AuthorDate: Wed Dec 11 14:55:27 2024 +0100
Commit:     Martin Jambor <jamborm@gcc.gnu.org>
CommitDate: Wed Dec 11 14:56:20 2024 +0100

    ipa: Update value range jump functions during inlining

Cc-ing Martin.


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163
[Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95)