[Bug target/116076] New: [15 Regression] slowdown of 433.milc on AMD Zen4

[pheeck at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116076

            Bug ID: 116076
           Summary: [15 Regression] slowdown of 433.milc on AMD Zen4
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: needs-bisection
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pheeck at gcc dot gnu.org
            Blocks: 26163
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

As seen here

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=992.70.0

there was a 4.5% exec time slowdown of the 433.milc SPEC 2006 benchmark between
commits

r15-2045-g61c21a719e205f
r15-2061-gacd4ab8d6e8938

when run with -Ofast -march=native -flto on an AMD Zen4 machine.


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)