JDK-8369448 : C2 SuperWord: refactor VTransform to do move_unordered_reduction_out_of_loop during VTransform::optimize
  • Type: Sub-task
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 26
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2025-10-08
  • Updated: 2025-11-14
  • Resolved: 2025-10-14
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JDK 26
26 b20Fixed
Related Reports
Causes :  
JDK-8371065 - C2 SuperWord: VTransformLoopPhiNode::apply setting type leads to assert/wrong result
Causes :  
JDK-8371881 - C2: Fix potential SEGV in VTransformReductionVectorNode tracing
Causes :  
JDK-8371472 - C2 compilation fails with "Error mixing types: vectory and int:0"
Description
This is one of the steps for Cost-Modeling JDK-8340093:

4. Optimize: e.g. move reduction out of loop
  - Refactor move_unordered_reduction_out_of_loop
  - Moving the reduction out of the loop will mean it is not counted in the cost any more, and it is now more profitable (see step 5)
Comments
Changeset: 4786f8be Branch: master Author: Emanuel Peter <epeter@openjdk.org> Date: 2025-10-14 08:32:32 +0000 URL: https://git.openjdk.org/jdk/commit/4786f8bee5c79c1bcf652758a25360b4d308ce1c
14-10-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/27704 Date: 2025-10-08 19:42:38 +0000
08-10-2025