JDK-8178811 : Minimize the AVX <-> SSE transition penalty through generation of vzeroupper instruction on x86
- Type: Enhancement
- Component: hotspot
- Sub-Component: compiler
- Affected Version: 9,10
- Priority: P2
- Status: Resolved
- Resolution: Fixed
- CPU: x86
- Submitted: 2017-04-14
- Updated: 2022-01-12
- Resolved: 2017-05-06
The Version table provides details related to the release that this issue/RFE will be addressed.
Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.
To download the current JDK release, click here.
Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.
To download the current JDK release, click here.
| JDK 10 |
|---|
10 b21Fixed  |
Related Reports
|
Relates :
|
|
|
Relates :
|
Description
This fix minimizes the AVX to SSE and SSE to AVX transition penalty through generation of vzeroupper instruction. With this patch we see zero transitions with penalty per SPECjbb2015 jOPS on BDW and a significant reduction on SKX CPU event vector width mismatch from 65 to 0.01 per SPECjbb2015 jOPS. We have also implemented an enhancement to disable vzeroupper generation for Knights family where the instruction has high penalty and is not recommended. The option UseVzeroupper is used to control generation of vzeroupper instruction and gets set to false on the Knights family. We observed ~3% gain on SPECJvm2008 composite result on Skylake.
Comments
|