JDK-8284533 : Improve InterpreterCodelet data footprint
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 11,17,18,19
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2022-04-07
  • Updated: 2022-11-17
  • Resolved: 2022-04-08
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JDK 17 JDK 19
17.0.6Fixed 19 b18Fixed
Related Reports
Relates :  
JDK-8284578 - Relax InterpreterCodelet stub alignment
Description
Current InterpreterCodelet lays the field in inefficient order: 

sizeof: 24
_size: @0
_description: @8
_bytecode: @16

Stub generation aligns codelets and their related code at CodeEntryAlignment, which means with CEA=16 we are taking two CEA units for InterpreterCodelet data. Rearranging the fields a bit improves the interpreter code density a bit, dropping its sizeof to 16 and thus taking one CEA unit.
Comments
Fix request (17u): This is a simple rearrangement of 2 fields leading to better codelets density. Original patch does not apply but is trivial to follow, product fields are the same. PR: https://github.com/openjdk/jdk17u-dev/pull/878 Testing: tier1, tier2 on aarch64.
14-11-2022
A pull request was submitted for review. URL: https://git.openjdk.org/jdk17u-dev/pull/878 Date: 2022-11-10 18:21:32 +0000
10-11-2022
Changeset: 61698bd1 Author: Aleksey Shipilev <shade@openjdk.org> Date: 2022-04-08 15:18:59 +0000 URL: https://git.openjdk.java.net/jdk/commit/61698bd137fc8ffad6a63b57b73df699712527b9
08-04-2022
A pull request was submitted for review. URL: https://git.openjdk.java.net/jdk/pull/8147 Date: 2022-04-07 15:02:48 +0000
07-04-2022