JDK-8287349 : AArch64: Merge LDR instructions to improve C1 OSR performance
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 17,19
  • Priority: P4
  • Status: Closed
  • Resolution: Fixed
  • CPU: aarch64
  • Submitted: 2022-05-26
  • Updated: 2024-01-08
  • Resolved: 2022-06-15
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JDK 17 JDK 20
17.0.6-oracleFixed 20 b03Fixed
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Description
Since MacroAssembler added merge_ldst, we can use different 
destination registers for contiguous-memory LDR instructions to improve performance.
Comments
Dmitry, as you pulled in the backport to 17u, I assume it is on you to revert it again with JDK-8310844 backport :) Tell me if you need someone to do this instead.
08-01-2024

As the current mainline fix is to revert the optimization, 17u fix should be the same.
04-01-2024

This caused a regression, see JDK-8310844.
04-01-2024

Fix Request (17u): This is a trivial performance fix for aarch64. The diff is tiny and does straightforward replacement to pair load-store instructions. PR: https://github.com/openjdk/jdk17u-dev/pull/661 Original patch applies cleanly. Testing: jtreg tier1, tier2 on linux-aarch64.
08-09-2022

A pull request was submitted for review. URL: https://git.openjdk.org/jdk17u-dev/pull/661 Date: 2022-09-08 13:00:00 +0000
08-09-2022

Changeset: 08400f18 Author: Zhuojun Miao <zmiao@openjdk.org> Committer: Tobias Hartmann <thartmann@openjdk.org> Date: 2022-06-15 05:57:55 +0000 URL: https://git.openjdk.org/jdk/commit/08400f18badb23ea3d00282e8b71e76844398a67
15-06-2022

A pull request was submitted for review. URL: https://git.openjdk.java.net/jdk/pull/8933 Date: 2022-05-28 06:28:57 +0000
28-05-2022