On Fri, 19 Jul 2024 22:28:40 GMT, Claes Redestad <redes...@openjdk.org> wrote:
>> Shaojin Wen has updated the pull request incrementally with two additional >> commits since the last revision: >> >> - Update src/java.base/share/classes/java/lang/String.java >> >> Co-authored-by: Chen Liang <li...@openjdk.org> >> - add comments > > FWIW one of the ideas when implementing `StringConcatHelper.simpleConcat` was > that by using the primitives used by the `StringConcatFactory` as > straightforwardly as possible the method acts as a documentation-of-sorts or > guide to understand how the `SCF` expression trees are built up. It's not > perfect, though. Concatenation of a `String` + constant would be handled > differently for one. So perhaps the value as a guide is not high. > > I'm also experimenting with replacing the MH-based strategy with spinning > hidden, shareable classes instead. In that case we might actually be better > off getting rid of the `long indexCoder` hacks and generate code more similar > to the `doConcat` you've come up with here. The main benefit of combining > `coder` and `index/length` into a single `long` was to reduce the MH > combinator overheads, but if we're spinning code with access to optimized > primitives then that isn't really needed. @cl4es Is it your idea to provide some String + primitive doConcat method and use it in StringConcatFactory to generate MH? doConcat(String,boolean) doConcat(String,char) doConcat(String,int) doConcat(String,long) doConcat(boolean, String) doConcat(char, String) doConcat(int, String) doConcat(long, String) ------------- PR Comment: https://git.openjdk.org/jdk/pull/20253#issuecomment-2240494811
