[Bug tree-optimization/126051] New: [17 Regression] 9% slowdown of 510.parest_r on Aarch64

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126051

            Bug ID: 126051
           Summary: [17 Regression] 9% slowdown of 510.parest_r on Aarch64
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Keywords: needs-bisection
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pheeck at gcc dot gnu.org
            Blocks: 26163
  Target Milestone: ---
              Host: aarch64-gnu-linux
            Target: aarch64-gnu-linux

As seen here

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=583.457.0

there was a 9% exec time slowdown of the 510.parest_r SPEC 2017 benchmark
between commits

r17-1605-gb5d5f34aa79790
r17-1770-g372ff3c0613e11

when compiled with -Ofast -march=native PGO (-fprofile-use) on an Ampere Altra
Neoverse N1 machine.


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)