https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107413
Bug ID: 107413
Summary: Perf loss ~14% on 519.lbm_r SPEC cpu2017 benchmark
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: rvmallad at amazon dot com
Target Milestone: ---
Created attachment 53775
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53775&action=edit
Input and source files.
Below is some perf data executing the 519.lbm_r benchmark on aarch64
architecture (Graviton 3 processor). I have comparison of the baseline perf
(mainline commit ID: f56d48b2471c388401174029324e1f4c4b84fcdb) vs. a fix for
the same (revert the code change in commit ID:
b5b33e113434be909e8a6d7b93824196fb6925c0).
Steps to compile:
$ gcc -std=c99 -mabi=lp64 -g -Ofast -mcpu=native lbm.i main.i -lm -flto -o
519_lbm_r_base
$ time ./519_lbm_r_base 3000 reference.dat 0 0 100_100_130_ldc.of
real 2m50.946s
Reverting the code changes in commit ID:
b5b33e113434be909e8a6d7b93824196fb6925c0
$ time ./519_lbm_r_fix 3000 reference.dat 0 0 100_100_130_ldc.of
real 2m27.157s
The code change reverted was:
[AArch64] PR84114: Avoid reassociating FMA
Author: Wilco Dijkstra <wdijk...@arm.com>
Date: Mon Mar 5 14:40:55 2018 +0000
Please find attached the files to reproduce this issue and the fix.
