JDK-8188313 : C2: Consider enabling auto-vectorization for simple reductions
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 9
  • Priority: P3
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2017-10-03
  • Updated: 2019-02-21
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.
Other
tbdUnresolved
Related Reports
Blocks :  
JDK-8214922 - AArch64: Add vectorization support for fmin/fmax
Relates :  
JDK-8078563 - Restrict reduction optimization
Description
Reconsider the decision to disable autovectorization for simple reductions made by JDK-8078563.

Richard Startin reports [1] that artificially complicating reduction operation (to make it eligible for auto-vectorization) produces a better result than original code (sum of elements). 

[1] http://richardstartin.uk/tricking-java-into-adding-up-arrays-faster/