https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109130
Bug ID: 109130
Summary: 464.h264ref regressed by 6.5% on a Neoverse-N1 CPU
with PGO, LTO, -Ofast and -march=native
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: jamborm at gcc dot gnu.org
CC: tnfchris at gcc dot gnu.org
Blocks: 26163
Target Milestone: ---
Host: aarch64-suse-linux
Target: aarch64-suse-linux
LNT shows what looks like a clear recent 6.5% regression on the
464.h264ref benchmark from SPEC 2006 CPU suite when compiled with
PGO, LTO, -Ofast and -march=native on a Neoverse-N1 CPU:
https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=586.220.0
In the same time period, I cannot (immediately) see any similar
regressions on any other CPU (all others that we monitor are x86_64)
or option combination.
Unfortunately I don't have the time and resources to further
investigate, but the commit range bad177e848787258..2fc55f51f9953b45
includes 8e26ac4749c (AArch64: Fix codegen regressions around tbz),
among other things.
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)
