[Bug middle-end/116790] New: [15 Regression] 6% slowdown of 454.calculix on AMD Zen 3

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116790

            Bug ID: 116790
           Summary: [15 Regression] 6% slowdown of 454.calculix on AMD Zen
                    3
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, needs-bisection
          Severity: normal
          Priority: P3
         Component: middle-end
          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=693.170.0

there was a 6% exec time slowdown of the 454.calculix SPEC 2006 benchmark
between commits

r15-3426-g36f63000c6f869
r15-3550-g75a4143d69a842

when run with -O2 -march=generic -flto PGO on an AMD Zen 3 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)