[Bug tree-optimization/123093] New: [16 Regression] 6% slowdown of 453.povray on Aarch64

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123093

            Bug ID: 123093
           Summary: [16 Regression] 6% slowdown of 453.povray on Aarch64
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, needs-bisection
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jmelcr at gcc dot gnu.org
                CC: 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=588.160.0

there was a 6% exec time slowdown of the 453.povray SPEC 2006 benchmark between
commits

r16-5960-g28f12e889c75c8
r16-6006-g3b3e153da546d3

when compiled with -Ofast -march=native -mtune=native -flto on an Ampere Altra
(Neoverse N1) machine.

This is a regression against GCC 15. See the comparison
here:

https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=624.160.0&plot.1=669.160.0&plot.2=593.160.0&plot.3=640.160.0&plot.4=609.160.0&plot.5=590.160.0&plot.6=750.160.0&plot.7=867.160.0&plot.8=1038.160.0&plot.9=1221.160.0&plot.10=588.160.0&;


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)