JDK-8237082 : Workaround C2 limitations when working with long loops
  • Type: Bug
  • Component: tools
  • Sub-Component: jextract
  • Affected Version: repo-panama
  • Priority: P3
  • Status: Closed
  • Resolution: Fixed
  • Submitted: 2020-01-14
  • Updated: 2020-12-16
  • Resolved: 2020-12-16
Related Reports
Relates :  
JDK-8223051 - support loops with long (64b) trip counts
Relates :  
JDK-8237077 - C2 fails to optimize certain code shapes with memory access indexed var handles
Description
Hotspot and Graal both have well-known issues when it comes to support bound-check-elimination in the presence of loops with 'long' induction variables.

One possible, interim, solution would be to workaround this limitation in the foreign memory access implementation, by special casing 'small' memory segments.
Comments
Changeset: 5249395528dc Author: mcimadamore Date: 2020-01-15 10:50 +0000 URL: https://hg.openjdk.java.net/panama/dev/rev/5249395528dc
16-12-2020