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rust/compiler/rustc_codegen_llvm
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Guillaume Gomez 095ca33bb6
Rollup merge of #128149 - RalfJung:nontemporal_store, r=jieyouxu,Amanieu,Jubilee 
nontemporal_store: make sure that the intrinsic is truly just a hint

The `!nontemporal` flag for stores in LLVM *sounds* like it is just a hint, but actually, it is not -- at least on x86, non-temporal stores need very special treatment by the programmer or else the Rust memory model breaks down. LLVM still treats these stores as-if they were normal stores for optimizations, which is [highly dubious](https://github.com/llvm/llvm-project/issues/64521). Let's avoid all that dubiousness by making our own non-temporal stores be truly just a hint, which is possible on some targets (e.g. ARM). On all other targets, non-temporal stores become regular stores.

~~Blocked on https://github.com/rust-lang/stdarch/pull/1541 propagating to the rustc repo, to make sure the `_mm_stream` intrinsics are unaffected by this change.~~

Fixes https://github.com/rust-lang/rust/issues/114582
Cc `@Amanieu` `@workingjubilee`
2024-08-12 17:09:14 +02:00
..
src Rollup merge of #128149 - RalfJung:nontemporal_store, r=jieyouxu,Amanieu,Jubilee 2024-08-12 17:09:14 +02:00
Cargo.toml dedup object 2024-07-28 17:21:07 +03:00
messages.ftl Move mingw dlltool invocation to cg_ssa 2024-07-30 10:33:33 +00:00
README.md mv compiler to compiler/ 2020-08-30 18:45:07 +03:00

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.