News for hackers. Stuff that matters.

A comment on Branchless Lomuto Partitioning. Parent comment

Re:Branchless Lomuto Partitioning by orlp on Wednesday December 06, 2023 @07:57AM (#38543217)
That's actually fair enough. I'm not certain how well the CPU will like the overlapping SIMD reads/writes on the left hand side.

If you have AVX512 available shuffle(xs, lut[movemask(compare_result)]) could also be two compressions with one reverse shuffle in between.

[ Parent | on HN ]
Re:Branchless Lomuto Partitioning by anonymoushn on Wednesday December 06, 2023 @08:10AM (#38543357)
I don't know either! I've never done something like this. Usually I am filtering to the same buffer or one or two other buffers, so I would never immediately load some stuff I had just stored.
[ Parent | on HN ]