[Bug tree-optimization/72517] New: 436.cactusADM: More than 40% regression in O3 and Ofast on AMD bdver4 m/c.

[Amit.Pawar at amd dot com]

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 
Date:   Wed Jun 15 09:53:07 2016 +

2016-06-15  Richard Biener  

* 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  TrunkDifference
O3  37.69   20.2-46%
O3 bdver4   36.55   32.2-12%
Ofast   40.36   24  -41%
Ofast bdver438.31   35.4-8%

[Bug tree-optimization/72517] [7 Regression] 436.cactusADM: More than 40% regression in O3 and Ofast on AMD bdver4 m/c.

[Amit.Pawar at amd dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72517

Amit Pawar  changed:

   What|Removed |Added

 Status|RESOLVED|REOPENED
 Resolution|FIXED   |---

--- Comment #6 from Amit Pawar  ---
Didn't notice any improvement with Ofast and Ofast -march=bdver4. Checking for
O3.

[Bug tree-optimization/72517] [7 Regression] 436.cactusADM: More than 40% regression in O3 and Ofast on AMD bdver4 m/c.

[Amit.Pawar at amd dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72517

--- Comment #11 from Amit Pawar  ---
Improvement is seen but not same as best one. 


Current scores are
Flags   Latest trunk
O3  :31.4
O3 -march=bdver4:31.1
Ofast   :32.1
Ofast -march=bdver4 :31.2

but good one.
Flags   Good Trunk
O3  37.69   
O3 bdver4   36.55   
Ofast   40.36
Ofast bdver438.31

Can you please check at your end?