Improve documentation for codegen options #141554
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| @@ -379,7 +396,7 @@ This flag controls the optimization level. | |||
| * `2`: some optimizations. | |||
| * `3`: all optimizations. | |||
| * `s`: optimize for binary size. | |||
| * `z`: optimize for binary size, but also turn off loop vectorization. | |||
| * `z`: optimize for binary size, but more aggressively. Often results in larger binaries than `s` | |||
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I took the description from https://llvm.org/doxygen/classllvm_1_1OptimizationLevel.html#a1e916712888d6a2d3952834c126460e7
The fact that it's often worse is based on experience
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I'd guess the old information was based on https://stackoverflow.com/questions/15548023/clang-optimization-levels
But that misses all the heuristics that are also affected by this flag, which are much more important (there's no way just not doing vectorization results in significantly bigger binaries)
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This adds more information to many different codegen options. It should not add any new guarantees, just document existing behavior.
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@bors r+ rollup=always |
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Rollup of 9 pull requests Successful merges: - #141554 (Improve documentation for codegen options) - #141817 (rustc_llvm: add Windows system libs only when cross-compiling from Wi…) - #141843 (Add `visit_id` to ast `Visitor`) - #141881 (Subtree update of `rust-analyzer`) - #141898 ([rustdoc-json] Implement PartialOrd and Ord for rustdoc_types::Id) - #141921 (Disable f64 minimum/maximum tests for arm 32) - #141930 (Enable triagebot `[concern]` functionality) - #141936 (Decouple "reporting in deps" from `FutureIncompatibilityReason`) - #141949 (move `test-float-parse` tool into `src/tools` dir) r? `@ghost` `@rustbot` modify labels: rollup
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Rollup merge of #141554 - Noratrieb:document-codegen-opts-better, r=bjorn3 Improve documentation for codegen options This adds more information to many different codegen options. It should not add any new guarantees, just document existing behavior. r? bjorn3
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…ommend-over-recommended, r=lqd Fix incorrect use of "recommend" over "recommended" Spotted this typo in rust-lang#141554, but it has since been merged. r? `@Noratrieb`
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Rollup of 9 pull requests Successful merges: - rust-lang/rust#141554 (Improve documentation for codegen options) - rust-lang/rust#141817 (rustc_llvm: add Windows system libs only when cross-compiling from Wi…) - rust-lang/rust#141843 (Add `visit_id` to ast `Visitor`) - rust-lang/rust#141881 (Subtree update of `rust-analyzer`) - rust-lang/rust#141898 ([rustdoc-json] Implement PartialOrd and Ord for rustdoc_types::Id) - rust-lang/rust#141921 (Disable f64 minimum/maximum tests for arm 32) - rust-lang/rust#141930 (Enable triagebot `[concern]` functionality) - rust-lang/rust#141936 (Decouple "reporting in deps" from `FutureIncompatibilityReason`) - rust-lang/rust#141949 (move `test-float-parse` tool into `src/tools` dir) r? `@ghost` `@rustbot` modify labels: rollup
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…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#141554 (Improve documentation for codegen options) - rust-lang#141817 (rustc_llvm: add Windows system libs only when cross-compiling from Wi…) - rust-lang#141843 (Add `visit_id` to ast `Visitor`) - rust-lang#141881 (Subtree update of `rust-analyzer`) - rust-lang#141898 ([rustdoc-json] Implement PartialOrd and Ord for rustdoc_types::Id) - rust-lang#141921 (Disable f64 minimum/maximum tests for arm 32) - rust-lang#141930 (Enable triagebot `[concern]` functionality) - rust-lang#141936 (Decouple "reporting in deps" from `FutureIncompatibilityReason`) - rust-lang#141949 (move `test-float-parse` tool into `src/tools` dir) r? `@ghost` `@rustbot` modify labels: rollup
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This adds more information to many different codegen options. It should not add any new guarantees, just document existing behavior.
r? bjorn3