[Bug target/123047] New: [16 Regression] 17% slowdown of 436.cactusADM on Aarch64

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123047

            Bug ID: 123047
           Summary: [16 Regression] 17% slowdown of 436.cactusADM on
                    Aarch64
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, 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: aarch64-gnu-linux
            Target: aarch64-gnu-linux

As seen here

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=586.100.0

there was a 17% exec time slowdown of the 436.cactusADM SPEC 2006 benchmark
between commits

r16-5210-g08e9df25462097
r16-5267-gc47f1462745887

when compiled with -Ofast -march=native -flto -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 (2k17, 2k and 2k6 and 95)