On the mailing list, Anton Hägerstrand <anton@blunders.io> posted a link to a blog post showing hotspots in our indexing: https://blunders.io/posts/lucene-bench-2021-01-10 and identified vecto dot product computations as one of them. Not surprising in itself, but he also suggested we might want to try using Math.fma in the computation to see if it can optimize the multiply-and-add operation that is at the heart of both the dot product and l2-norm distance.

Migrated from LUCENE-9679 by Michael Sokolov (@msokolov), resolved Mar 16 2021