JDK-8268858 : Determine register pressure automatically by the number of available registers for allocation
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 18
  • Priority: P4
  • Status: Closed
  • Resolution: Fixed
  • OS: generic
  • CPU: generic
  • Submitted: 2021-06-16
  • Updated: 2024-02-06
  • Resolved: 2021-06-23
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.
JDK 18
18 b03Fixed
Related Reports
Relates :  
JDK-8304328 - C2 Bailout "failed spill-split-recycle sanity check" reveals hidden issue with RA
Relates :  
JDK-8064625 - ARM: C2 register pressure looks wrong
Relates :  
JDK-8270824 - SPECjvm2008 compress regression on x86 when +PreserveFramePointer
Relates :  
JDK-8269598 - Regressions up to 5% on aarch64 seems due to JDK-8268858
Comments
Is there any plan to backport this patch to jdk17 and jdk11?
23-08-2022
[~dlong] I created JDK-8270824 to track "compress" regression with -XX:+PreserveFramePointer after JDK-8268858. JDK-8270808 is used to track performance degradation I found in Flink Nexmark benchmark with -XX:+PreserveFramePointer before JDK-8268858.
16-07-2021
[~jzhu] Please try SPECjvm2008 compress on x86/x64 with -XX:+PreserveFramePointer. We are seeing a regression after JDK-8268858.
15-07-2021
Seems to have caused a regression on aarch64. See https://bugs.openjdk.java.net/browse/JDK-8269598
30-06-2021
Changeset: 36d82b6e Author: Joshua Zhu <jzhu@openjdk.org> Committer: Yi Yang <yyang@openjdk.org> Date: 2021-06-23 03:54:00 +0000 URL: https://git.openjdk.java.net/jdk/commit/36d82b6ef18d8add5f97fad507b7d86d702bdf13
23-06-2021