[lworld] RFR: 8255541: [lworld] Improve array layout checks in C2 compiled code

Wed Oct 28 14:01:02 UTC 2020

C2 should use a single bit test of the layout helper value to check for flat/null-free inline type arrays. This is a prerequisite of JDK-8255046 which will then add support for checking the corresponding bits in the mark word instead.

Best regards,
Tobias

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Commit messages:
 - 8255541: [lworld] Improve array layout checks in C2 compiled code

Changes: https://git.openjdk.java.net/valhalla/pull/244/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=244&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8255541
  Stats: 168 lines in 8 files changed: 32 ins; 73 del; 63 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/244.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/244/head:pull/244

PR: https://git.openjdk.java.net/valhalla/pull/244