This PR proposes adding a new method to BitSet that provides an immutable snapshot of the set in the form of an `IntPredicate`.
The predicate is eligible for constant folding. Here are some classes in the JDK that would benefit directly from constant-folding of BitSets: PoolReader (6) URLEncoder (1) - Updated in this PR HtmlTree (2) More over, the implementation of the predicate is @ValueBased and this would provide additional benefits in the future. Initial benchmarks with the URLEncoder show encouraging results: Name (encodeChars) (maxLength) (unchanged) Cnt Base Error Test Error Unit Diff% URLEncodeDecode.testEncodeUTF8 6 1024 0 15 2,371 ± 0,016 2,073 ± 0,184 ms/op 12,6% (p = 0,000*) URLEncodeDecode.testEncodeUTF8 6 1024 75 15 1,772 ± 0,013 1,387 ± 0,032 ms/op 21,8% (p = 0,000*) URLEncodeDecode.testEncodeUTF8 6 1024 100 15 1,230 ± 0,009 1,140 ± 0,011 ms/op 7,3% (p = 0,000*) ------------- Commit messages: - Add test and remove updates for some JDK classes Changes: https://git.openjdk.org/jdk/pull/15530/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15530&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8315454 Stats: 153 lines in 3 files changed: 140 ins; 1 del; 12 mod Patch: https://git.openjdk.org/jdk/pull/15530.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/15530/head:pull/15530 PR: https://git.openjdk.org/jdk/pull/15530
