Perform LTO optimisations with wasm-ld + -Clinker-plugin-lto #118378
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| LinkerPluginLto::Disabled => { | ||
| // Nothing to do | ||
| } | ||
| LinkerPluginLto::LinkerPluginAuto => { |
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| LinkerPluginLto::LinkerPluginAuto => { | |
| LinkerPluginLto::LinkerPluginAuto | LinkerPluginLto::LinkerPlugin(_) => { |
push_linker_plugin_lto_args could then be inlined and removed.
Upd: the match on self.sess.opts.optimize could be kept separate function, though, it is shared between fn optimize and fn linker_plugin_lto.
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I intentionally left them separate.
- That the match turns out the same is more of a coincidence than anything else. I anticipate the
--lto-O*args may change to support Os and Oz in future. (Especially with those being the most popular opt levels for webassembly.) If that happens, adding Os/Oz to a shared match statement would break the normalfn optimizethat controls merging sections only, unrelated to LLVM. push_linker_plugin_lto_argscould be inlined, but I was going to do another PR that puts warnings in one of the match arms but not the other.
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@bors r+ rollup |
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Nov 28, 2023
| config::OptLevel::Less => "O1", | ||
| config::OptLevel::Default => "O2", | ||
| config::OptLevel::Aggressive => "O3", | ||
| // wasm-ld only handles integer LTO opt levels. Use O2 |
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| // wasm-ld only handles integer LTO opt levels. Use O2 | |
| // `wasm-ld` only handles integer LTO opt levels. Use O2. |
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…iaskrgr Rollup of 6 pull requests Successful merges: - rust-lang#118193 (Add missing period in `std::process::Command` docs) - rust-lang#118222 (unify read_to_end and io::copy impls for reading into a Vec) - rust-lang#118323 (give dev-friendly error message for incorrect config profiles) - rust-lang#118378 (Perform LTO optimisations with wasm-ld + -Clinker-plugin-lto) - rust-lang#118399 (Clean dead codes in miri) - rust-lang#118410 (update test for new LLVM 18 codegen) r? `@ghost` `@rustbot` modify labels: rollup
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…iaskrgr Rollup of 6 pull requests Successful merges: - rust-lang#118193 (Add missing period in `std::process::Command` docs) - rust-lang#118222 (unify read_to_end and io::copy impls for reading into a Vec) - rust-lang#118323 (give dev-friendly error message for incorrect config profiles) - rust-lang#118378 (Perform LTO optimisations with wasm-ld + -Clinker-plugin-lto) - rust-lang#118399 (Clean dead codes in miri) - rust-lang#118410 (update test for new LLVM 18 codegen) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of rust-lang#118378 - cormacrelf:bugfix/linker-plugin-lto-wasm, r=petrochenkov Perform LTO optimisations with wasm-ld + -Clinker-plugin-lto Fixes (partially) rust-lang#60059. Technically, `--target wasm32-unknown-unknown -Clinker-plugin-lto` would complete without errors before, but it was not producing optimized code. At least, it may have been but it was probably not the opt-level people intended. Similarly to rust-lang#118377, this could benefit from a warning about using an explicit libLTO path with LLD, which will ignore it and use its internal LLVM. Especially given we always use lld on wasm targets. I left the code open to that possibility rather than making it perfectly neat.
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Fixes (partially) #60059. Technically,
--target wasm32-unknown-unknown -Clinker-plugin-ltowould complete without errors before, but it was not producing optimized code. At least, it may have been but it was probably not the opt-level people intended.Similarly to #118377, this could benefit from a warning about using an explicit libLTO path with LLD, which will ignore it and use its internal LLVM. Especially given we always use lld on wasm targets. I left the code open to that possibility rather than making it perfectly neat.