kaivalnp commented on issue #15697: URL: https://github.com/apache/lucene/issues/15697#issuecomment-3931276740
> Seeing the same kind of warmup behavior on a Mac M2 Ah thanks, my machine was an AWS Graviton3 -- so this issue(?) may be related to ARM Something strange: the degradation does not occur if we separate [this](https://github.com/apache/lucene/blob/e1879e450b75b3a58fde2b0dad77ae6b499504dd/lucene/core/src/java25/org/apache/lucene/internal/vectorization/PanamaVectorUtilSupport.java#L596-L612) into two separate loops (upper and lower): ``` Benchmark (size) Mode Cnt Score Error Units VectorUtilBenchmark.binaryHalfByteDotProductSinglePackedScalar 1024 thrpt 15 2.447 ± 0.008 ops/us VectorUtilBenchmark.binaryHalfByteDotProductSinglePackedVector 1024 thrpt 15 13.275 ± 0.341 ops/us ``` ..which seems counter intuitive, because the "packed" vector is loaded twice (perhaps C2 compiles it "correctly" under the hood). I'm also unsure if this is an actual issue, or just occurs in JMH benchmarks.. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
