JDK-8290965 : PPC64: Implement post-call NOPs
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 20
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • CPU: ppc
  • Submitted: 2022-07-25
  • Updated: 2024-01-23
  • Resolved: 2024-01-17
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JDK 23
23 b06Fixed
Related Reports
Blocks :  
JDK-8322294 - Cleanup NativePostCallNop
Relates :  
JDK-8286302 - Port JEP 425 to PPC64
Description
Post-call NOPs encode the offset from a compiled call to the CodeBlob the compiled call belongs to. This allows for quick CodeBlob look-up when iterating compiled stack frames.

[~rpressler] commented on the review of JDK-8287567: "The NOPs make a big difference for various stack walking operations, and while we did see some negative effects, they're probably very minor. However, because they're only generated in JDK 19 if preview is enabled, we can perform a deeper performance analysis later."

Also make use of the quick lookup when reconstructing the back chain during fast thaw (see `Thaw<ConfigT>::patch_caller_links()`)
Comments
Changeset: de97c0eb Author: Richard Reingruber <rrich@openjdk.org> Date: 2024-01-17 06:50:32 +0000 URL: https://git.openjdk.org/jdk/commit/de97c0eb4bbeece0dfab3065c260c7f5434060a7
17-01-2024
A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/17171 Date: 2023-12-20 19:56:28 +0000
20-12-2023
Helidon Nima could be a benchmark for the effect of post-call NOPs
24-05-2023