> This PR suggests we can speed up `StringLatin1.regionMatchesCI` by applying
> 'the oldest ASCII trick in the book'.
>
> The new static method `CharacterDataLatin1.equalsIgnoreCase` compares two
> latin1 bytes for equality ignoring case. `StringLatin1.regionMatchesCI` is
> updated to use `equalsIgnoreCase`
>
> To verify the correctness of `equalsIgnoreCase`, a new test is added to
> `EqualsIgnoreCase` with an exhaustive verification that all 256x256 latin1
> code point pairs have an `equalsIgnoreCase` consistent with
> Character.toUpperCase, Character.toLowerCase.
>
> Performance is tested for matching and mismatching cases of code point pairs
> picked from the ASCII letter, ASCII number and latin1 letter ranges. Results
> in the first comment below.
Eirik Bjorsnos has updated the pull request with a new target base due to a
merge or a rebase. The incremental webrev excludes the unrelated changes
brought in by the merge/rebase. The pull request contains 20 additional commits
since the last revision:
- Merge branch 'master' into regionmatches-latin1-speedup
- Make the loop variables chars to avoid casting
- Use improved case-twiddling comment as suggested by Martin
- Replace 'oldest ASCII trick in the book' use in toUpperCase, toLowerCase
with "by removing (setting) a single bit"
- Align local variable naming in toLowerCase, toUpperCase with
equalsIgnoreCase by using 'lower' and 'upper'
- Rename unconventionally named local variable 'U' to 'upper'
- Merge remote-tracking branch 'origin/master' into
regionmatches-latin1-speedup
- Add whitespace between methods
- Merge branch 'master' into regionmatches-latin1-speedup
- Remove whitespace following '('
- ... and 10 more: https://git.openjdk.org/jdk/compare/ea132c56...fe4efe9f
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/12632/files
- new: https://git.openjdk.org/jdk/pull/12632/files/cc185293..fe4efe9f
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=12632&range=12
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=12632&range=11-12
Stats: 1397 lines in 120 files changed: 873 ins; 291 del; 233 mod
Patch: https://git.openjdk.org/jdk/pull/12632.diff
Fetch: git fetch https://git.openjdk.org/jdk pull/12632/head:pull/12632
PR: https://git.openjdk.org/jdk/pull/12632
