RFR: 8329726: Use non-short forward jumps in lightweight locking

Roman Kennke rkennke at openjdk.org
Fri Apr 5 13:38:19 UTC 2024


This turns a few short-jumps to long-jumps in x86 lightweight locking code paths. When running with -XX:+ShowMessageBoxOnError, MA::stop() generates more code and jccb is not sufficient to address this.

Two of the jccb are in ASSERT path anyway. However, another is also in a product path. We *could* generate jccb or jcc conditionally on ShowMessageBoxOnError, however, I don't think it is worth the trouble. WDYT?

Unfortunately, I could not make a simple test-case, because ShowMessageBoxOnError stops and waits on error, which would make jtreg time-out.

Testing:
 - [x] manual test with dacapo as provided in the bug report
 - [ ] tier1

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Commit messages:
 - 8329726: Use non-short forward jumps in lightweight locking

Changes: https://git.openjdk.org/jdk/pull/18657/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18657&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8329726
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/18657.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18657/head:pull/18657

PR: https://git.openjdk.org/jdk/pull/18657


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