On Mon, 20 Feb 2023 14:45:09 GMT, Eirik Bjorsnos <d...@openjdk.org> wrote:
>> 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 incrementally with two additional > commits since the last revision: > > - Add @bug tag to EqualsIgnoreCase test for correct issue JDK-8302871 > - Add @bug tag to EqualsIgnoreCase test for JDK-8302877 src/java.base/share/classes/java/lang/CharacterDataLatin1.java.template line 170: > 168: * @return true if the two bytes are considered equals ignoring case > in latin1 > 169: */ > 170: static boolean equalsIgnoreCase(byte b1, byte b2) { Perhaps put this in `CharacterDataLatin1`, keeping it close to toLowerCase/toUpperCase that you're changing to use similar logic with #12623 If you apply #12623 first - how much difference does this make on the micro you're adding with this PR? ------------- PR: https://git.openjdk.org/jdk/pull/12632