Dougall

Marcin Żukowski’s PivCo-Huffman paper inspired me to revisit an Oodle-like 12-stream Huffman decoder for Apple CPUs that I experimented with in 2022. The same old kernel manages a pretty flat 5GB/s to 5.1GB/s on Apple M4, which did beat PivCo-Huffman, on one or two files, at the time of the paper. But with @rygorous@mastodon.gamedev.place's and Marcin's improvements, the updated PivCo-Huffman code reliably wins. And it doesn't need 31 GPRs. Very exciting work. https://gist.github.com/dougallj/a14d3f72b57ee58a81d487b43ff2a05b

@rygorous FWIW, your writing is hugely inspirational to me. I've learned some of my favourite ideas from your posts, like the throughput optimised bit-reading technique, and the texture swizzling bit-trick. And often your blog has let me understand things that I'd tried and failed to understand before, like FFT implementations, Huffman table initialisation, SIMD transposes, and triangle rasterisation. (Thank you!) This sucks, but many people still care about understanding.

Andreas Abel added latency, throughput, and port usage data for Emerald Rapids, Meteor Lake, Arrow Lake, and Zen 5 to https://uops.info/table.html 🎉