RFR: 8296374: Check for young region in G1BarrierSet::invalidate instead of card-by-card check

Wed Dec 14 17:05:59 UTC 2022

Hi,

Please review this change to young region card checks in G1BarrierSet::invalidate(). A single check should suffice because the MemRegion for invalidation in G1 is either completely in the young gen or not. 

Testing: Tier 1-3

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Commit messages:
 - early exit for g1 young cards

Changes: https://git.openjdk.org/jdk/pull/11677/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11677&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296374
  Stats: 8 lines in 1 file changed: 4 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/11677.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11677/head:pull/11677

PR: https://git.openjdk.org/jdk/pull/11677