https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81554
Bug ID: 81554
Summary: [8 Regression] 25% performance regression in Himeno
benchmark
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: kristerw at gcc dot gnu.org
Target Milestone: ---
Created attachment 41831
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41831&action=edit
The Himeno benchmark
The Himeno benchmark from the Phoronix test suite lost 25% of its performance
by r248771 that fixed PR 66313 ("Unsafe factorization of a*b+a*c").
The benchmark is attached, can be compiled as
gcc -O3 himenobmtxpa.c
and run as
./a.out s
I see 15% slowdown when the benchmark is compiled as "-O3" and 25% if compiled
as "-O3 -march=native" on a Broadwell CPU.
