uschindler commented on PR #12311: URL: https://github.com/apache/lucene/pull/12311#issuecomment-1564310637
Hi @alessandrobenedetti, the code shown here is indeed crazy to read, but this is more a problem of the APIs in general. The Java Vector API is very low level and you have to exactly know how lanes, species and so on work. The code written by Robert is 100% according to the javadocs guidelines. A lot of low level code (in codecs like BlockTermsReader is done like that). Also MMapDirectory indexinput look like that. They are not beatiful but optimized for performance. To me the variable names are perfectly fine vor vector code (`ab`, `a1b`,...). This is typical in that area. It won't get better with other names. The code on official JDK docs looks identical: https://docs.oracle.com/en/java/javase/20/docs/api/jdk.incubator.vector/jdk/incubator/vector/package-summary.html The arbitrary if/else constructs are a problem of underlying hardware infratstructure. It is NOT autogenerated, but follows low-level hardware specs, so there are arbitrary looking constants and if/else in it. This can be improved by moving numbers like 128 as constants, be free to make PRs! For performance reasons you should NOT split that up into too many different methods, as the code relies on escape analysis of the VM. We may split it later, but that's more a cleanup approach. An additional problem in the whole code is that it is Java version specific, so there will me multiple versions of the same code staying in different directories (java20, java21,...). Same for MMapDirectory. The extraction code for the Java APIs is special and a hack, but it is not part of Lucene's public library; it is a build tool only. Sorry for it, there's a new version now because a rewrite was needed to allow backporting and fix incomplete extraction: #12329 (this version looks much better, also technically bettrer organized). -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org
