b807d5970b
Arm's FEAT_FP and Feat_AdvSIMD describe the same thing on AArch64: The Neon unit, which handles both floating point and SIMD instructions. Moreover, a configuration for AArch64 must include both or neither. Arm says "entirely proprietary" toolchains may omit floating point: https://developer.arm.com/documentation/102374/0101/Data-processing---floating-point In the Programmer's Guide for Armv8-A, Arm says AArch64 can have both FP and Neon or neither in custom implementations: https://developer.arm.com/documentation/den0024/a/AArch64-Floating-point-and-NEON In "Bare metal boot code for Armv8-A", enabling Neon and FP is just disabling the same trap flag: https://developer.arm.com/documentation/dai0527/a In an unlikely future where "Neon and FP" become unrelated, we can add "[+-]fp" as its own feature flag. Until then, we can simplify programming with Rust on AArch64 by folding both into "[+-]neon", which is valid as it supersets both. "[+-]neon" is retained for niche uses such as firmware, kernels, "I just hate floats", and so on. |
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| Cargo.toml | ||
| README.md | ||
The codegen crate contains the code to convert from MIR into LLVM IR,
and then from LLVM IR into machine code. In general it contains code
that runs towards the end of the compilation process.
For more information about how codegen works, see the rustc dev guide.