https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72517
Bug ID: 72517
Summary: 436.cactusADM: More than 40% regression in O3 and
Ofast on AMD bdver4 m/c.
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: Amit.Pawar at amd dot com
Target Milestone: ---
Starting from git commit id 5695a690b29a98205a8ae29a6072fd2e42cf1c84 cactusADM
showing >40% regression with generic and > 8% with native on AMD BDVER4
machine. Following table describes the flags used.
Git bisecting shows
5695a690b29a98205a8ae29a6072fd2e42cf1c84 is the first bad commit
commit 5695a690b29a98205a8ae29a6072fd2e42cf1c84
Author: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Wed Jun 15 09:53:07 2016 +0000
2016-06-15 Richard Biener <rguent...@suse.de>
* tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Do
not consider dependences between accesses that belong to the
same group.
(vect_analyze_data_ref_dependences): Do not analyze read-read
or self-dependences.
* gcc.dg/vect/bb-slp-pattern-2.c: Disable loop vectorization.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@237473
138bc75d-0d04-0410-961f-82ee72b054a4
Git id "61958e92f84b20ec65157388ac221d0f23291b03" (good trunk) produces good
score on bdver4. Tested on bdver2,bdver3 and bdver4 machines and shows only on
bdver4.
Flags Good Trunk Trunk Difference
O3 37.69 20.2 -46%
O3 bdver4 36.55 32.2 -12%
Ofast 40.36 24 -41%
Ofast bdver4 38.31 35.4 -8%
