Support 1st group of RISC-V Bitmanip backend target features #100528
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These use the same names as LLVM and is_riscv_feature_detected!: - zba (address generation instructions) - zbb (basic bit manipulation) - zbc (carry-less multiplication) - zbs (single-bit manipulation)
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Even if it did, we could always remap the feature name like we already do for a couple of stabilized features. (Although in those cases we remapped them to give a less confusing name rather than because LLVM changed the name I believe.) |
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…iaskrgr Rollup of 10 pull requests Successful merges: - rust-lang#100031 (improve "try ignoring the field" diagnostic) - rust-lang#100325 (Rustdoc-Json: Don't remove impls for items imported from private modules) - rust-lang#100377 (Replace - with _ in fluent slugs to improve developer workflows) - rust-lang#100458 (Adjust span of fn argument declaration) - rust-lang#100514 (Delay span bug when failing to normalize negative coherence impl subject due to other malformed impls) - rust-lang#100528 (Support 1st group of RISC-V Bitmanip backend target features) - rust-lang#100559 (Parser simplifications) - rust-lang#100568 (Fix STD build for ESP-IDF) - rust-lang#100582 ([rustdoc] Fix handling of stripped enum variant in JSON output format) - rust-lang#100586 (Reland changes replacing num_cpus with available_parallelism ) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
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These target features use the same names as LLVM and
is_riscv_feature_detected!, they are:The extension is frozen and ratified, and I don't think we should expect LLVM to change those feature names in the future.
For reference, the specification for the B extension can be found here: https://github.com/riscv/riscv-bitmanip/releases/download/1.0.0/bitmanip-1.0.0-38-g865e7a7.pdf)
On my current project, I see a 7.6% reduction in binary size with these features on, so I have some incentive to try to silence the "unknown feature" warning from
-Ctarget-feature=)