[Bug target/125664] New: [17 Regression] 4% slowdown of sphinx3 on Aarch64

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125664

            Bug ID: 125664
           Summary: [17 Regression] 4% slowdown of sphinx3 on Aarch64
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, needs-bisection
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jmelcr at gcc dot gnu.org
            Blocks: 26163
  Target Milestone: ---
              Host: aarch64-suse-linux
            Target: aarch64-suse-linux
             Build: aarch64-suse-linux

As seen here

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=575.280.0

there was a 4% exec time slowdown of the sphinx3 SPEC 2006 benchmark between
commits

r17-702-g5d0a9050f3a1c1
r17-1049-gfd6d39208ba4ed

when compiled with -Ofast -g on an Ampere Altra Neoverse N1 machine.

This is a regression against previous GCC versions. See the comparison
here:

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=638.280.0&plot.1=675.280.0&plot.2=594.280.0&plot.3=653.280.0&plot.4=615.280.0&plot.5=600.280.0&plot.6=767.280.0&plot.7=873.280.0&plot.8=1054.280.0&plot.9=1226.280.0&plot.10=1526.280.0&plot.11=575.280.0&;


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163
[Bug 26163] [meta-bug] missed optimization in SPEC (2026, 2k17, 2k and 2k6 and
95)