Improve performance by optimizing bundle merging logic. #204
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While merging two bundles, the `merge_bundles` function appends two sorted vectors and sort the resulting vector again. This approach used to be fast in most cases, but rustc 1.81 introduced changes in sorting algorithm that made `sort_unstable_by_key` to behave very bad with vectors are that are almost sorted. This introduces an optimization consisting in handling the special case where the vector being appended contains a single item differently. This case is very common, and there's a benefit in handling it differently both with rust 1.81 and with earlier versions.
cfallin
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Thanks very much for this! I'll fuzz locally for a bit just for extra caution, then cut a new release and get this into Cranelift/Wasmtime.
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(I'm looking into the cargo-deny failure -- seems to be a license issue with a crate dependency) |
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Includes bytecodealliance#204 to fix a performance regression with Rust 1.81's new standard library sort function.
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Includes #204 to fix a performance regression with Rust 1.81's new standard library sort function.
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While merging two bundles, the
merge_bundlesfunction appends two sorted vectors and sort the resulting vector again. This approach used to be fast in most cases, but rustc 1.81 introduced changes in sorting algorithm that madesort_unstable_by_keyto behave very bad with vectors that are almost sorted.This introduces an optimization consisting in handling the special case where the vector being appended contains a single item differently. This case is very common, and there's a benefit in handling it differently both with rust 1.81 and with earlier versions.
Fixes #203