On Fri, 17 Feb 2023 17:31:09 GMT, Eirik Bjorsnos <d...@openjdk.org> wrote:
> This PR suggests we speed up Character.toUpperCase and Character.toLowerCase > for latin1 code points by applying the 'oldest ASCII trick in the book'. > > This takes advantage of the fact that latin1 uppercase code points are always > 0x20 lower than their lowercase (with the exception of two code points which > uppercase out of latin1). > > To verify the correctness of the new implementation, the test > `Latin1CaseConversion` is added with an exhaustive verification of > toUpperCase/toLowerCase for all latin1 code points. > > The implementation needs to balance the performance of the various ranges in > latin1. An effort has been made to favour operations on ASCII code points, > without causing excessive regression for higher code points. > > Performance is benchmarked for 7 chosen sample code points, each representing > a range or a special-case. Results in the first comment. This pull request has now been integrated. Changeset: ef1f7bd3 Author: Eirik Bjorsnos <eir...@gmail.com> Committer: Naoto Sato <na...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/ef1f7bd3b80f8777c15ab22b1dff7dfe4f084734 Stats: 166 lines in 5 files changed: 143 ins; 0 del; 23 mod 8302877: Speed up latin1 case conversions Reviewed-by: naoto, redestad ------------- PR: https://git.openjdk.org/jdk/pull/12623
