Stream: git-wasmtime

Topic: wasmtime / PR #7710 Add `sextend_maybe` and `uextend_mayb...

Wasmtime GitHub notifications bot (Dec 20 2023 at 01:54):

scottmcm opened PR #7710 from scottmcm:opt-extend-maybe to bytecodealliance:main:

Working on something else, I noticed that the (x < y) != 0 opt was written in a way that only works for C

https://github.com/bytecodealliance/wasmtime/blob/f8c9f6711f6316001801480d3883888734835faf/cranelift/codegen/src/opts/icmp.isle#L16-L25

whereas in Rust, which doesn't have the "usual arithmetic conversions", the result of the comparison stays as I8 and thus without the extension it didn't match that pattern.

This picks up a suggestion that alex had made in a previous PR (https://github.com/bytecodealliance/wasmtime/pull/7636#discussion_r1416208525) to make something like lowering ISLE's maybe_uextend extractor for optimization ISLE.

They're then used to improve the mentioned icmp-of-icmp pattern

https://github.com/bytecodealliance/wasmtime/commit/8ef0b8181ca23b9133a464da6ae10fa32ffdbf15#diff-fa420f878e321dc6579ac911f9ba8820a9381e4c49615584f6e6909f0e329dfcL124-R125

as well as simplify some of the duplication in the <=> patterns.

Wasmtime GitHub notifications bot (Dec 20 2023 at 01:54):

scottmcm requested elliottt for a review on PR #7710.

Wasmtime GitHub notifications bot (Dec 20 2023 at 01:54):

scottmcm requested wasmtime-compiler-reviewers for a review on PR #7710.

Wasmtime GitHub notifications bot (Dec 20 2023 at 04:44):

github-actions[bot] commented on PR #7710:

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cc @cfallin, @fitzgen

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Wasmtime GitHub notifications bot (Dec 20 2023 at 19:31):

fitzgen submitted PR review:

Nice!

Wasmtime GitHub notifications bot (Dec 20 2023 at 20:10):

fitzgen merged PR #7710.

Last updated: Dec 06 2025 at 06:05 UTC