By avoiding a bit shift operation for the latin1 fast-path test, we can speed up the `java.lang.CharacterData.of` method by ~25% for latin1 code points.
The latin1 test is currently implemented as `ch >>> 8 == 0`. We can replace this with `ch >= 0 && ch <= 0xFF` for a noticable performance gain (especially for ASCII chars): This methods is called frequently by various property-determining methods in `java.lang.Character` like `isLowerCase`, `isDigit` etc, so one should expect improvements for all these methods. Performance is tested using the `Characters.isDigit` benchmark using the digits '0' (decimal 48, in CharacterDataLatin1) and '\u0660' (decimal 1632, in CharacterData00): Baseline: Benchmark (codePoint) Mode Cnt Score Error Units Characters.isDigit 48 avgt 15 0.870 ± 0.011 ns/op Characters.isDigit 1632 avgt 15 2.168 ± 0.017 ns/op PR: Benchmark (codePoint) Mode Cnt Score Error Units Characters.isDigit 48 avgt 15 0.654 ± 0.007 ns/op Characters.isDigit 1632 avgt 15 2.032 ± 0.019 ns/op ------------- Commit messages: - Update copyright year - Avoid bit shifting in the CharacterDataLatin1 fast-path Changes: https://git.openjdk.org/jdk/pull/13040/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13040&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8304245 Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod Patch: https://git.openjdk.org/jdk/pull/13040.diff Fetch: git fetch https://git.openjdk.org/jdk pull/13040/head:pull/13040 PR: https://git.openjdk.org/jdk/pull/13040
