optimize branch update with small lookup tables

microsoft / lepton_jpeg_rust

Port of DropBox Lepton compression to Rust

Apache License 2.0

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Closed mcroomp closed 1 year ago

mcroomp commented 1 year ago

Use small lookup table to avoid branching during probability updates

mcroomp commented 1 year ago

@danielrh might find this amusing... finally figured out a way to handle the zero probability corner case without an extra branch

danielrh commented 1 year ago

I love this! :-) Did you have a microbenchmark comparison? Does it end up helping in practice