Use the trifecta div algorithm for 128-bit div on wasm #685
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This commit updates the `#[cfg]` annotations used to select the implementation of 128-bit division in compiler-builtins on wasm targets. This is done with relation to https://github.com/WebAssembly/128-bit-arithmetic where performance of 128-bit operations is being investigated on WebAssembly. While I don't know much about the particulars of the two algorithms involved here the comments indicate that the "trifecta" variant is preferred if possible but it's not selected on 32-bit architectures. This rationale isn't as applicable to WebAssembly targets because despite the 32-bit pointer width there are often wider-than-pointer operations available as it's typically run on 64-bit machines. Locally in testing a benchmark that performs division with a Rust-based bignum libraries whent from 350% slower-than-native to 220% slower-than-native with this change, a nice increase in speed. While this was tested with Wasmtime other runtimes are likely to see an improvement as well.
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Makes sense, thanks! |
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Once #684 merges you can send a PR to rust-lang/rust updating to v0.1.125 |
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Happy to do so, and thanks! |
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This commit updates the compiler-builtins crate from 0.1.123 to 0.1.125. The changes in this update are: * rust-lang/compiler-builtins#682 * rust-lang/compiler-builtins#678 * rust-lang/compiler-builtins#685
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…ins, r=tgross35 Update compiler-builtins to 0.1.125 This commit updates the compiler-builtins crate from 0.1.123 to 0.1.125. The changes in this update are: * rust-lang/compiler-builtins#682 * rust-lang/compiler-builtins#678 * rust-lang/compiler-builtins#685 Fixes: rust-lang#129823
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…s, r=<try> Update compiler-builtins to 0.1.125 This commit updates the compiler-builtins crate from 0.1.123 to 0.1.125. The changes in this update are: * rust-lang/compiler-builtins#682 * rust-lang/compiler-builtins#678 * rust-lang/compiler-builtins#685 try-job: aarch64-apple try-job: aarch64-gnu try-job: armhf-gnu try-job: test-various
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…ins, r=tgross35 Update compiler-builtins to 0.1.125 This commit updates the compiler-builtins crate from 0.1.123 to 0.1.125. The changes in this update are: * rust-lang/compiler-builtins#682 * rust-lang/compiler-builtins#678 * rust-lang/compiler-builtins#685
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…s, r=tgross35 Update compiler-builtins to 0.1.125 This commit updates the compiler-builtins crate from 0.1.123 to 0.1.125. The changes in this update are: * rust-lang/compiler-builtins#682 * rust-lang/compiler-builtins#678 * rust-lang/compiler-builtins#685
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…ss35 Update compiler-builtins to 0.1.125 This commit updates the compiler-builtins crate from 0.1.123 to 0.1.125. The changes in this update are: * rust-lang/compiler-builtins#682 * rust-lang/compiler-builtins#678 * rust-lang/compiler-builtins#685
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This commit updates the
#[cfg]annotations used to select the implementation of 128-bit division in compiler-builtins on wasm targets. This is done with relation tohttps://github.com/WebAssembly/128-bit-arithmetic where performance of 128-bit operations is being investigated on WebAssembly. While I don't know much about the particulars of the two algorithms involved here the comments indicate that the "trifecta" variant is preferred if possible but it's not selected on 32-bit architectures. This rationale isn't as applicable to WebAssembly targets because despite the 32-bit pointer width there are often wider-than-pointer operations available as it's typically run on 64-bit machines.
Locally in testing a benchmark that performs division with a Rust-based bignum libraries whent from 350% slower-than-native to 220% slower-than-native with this change, a nice increase in speed. While this was tested with Wasmtime other runtimes are likely to see an improvement as well.