rust/compiler/rustc_codegen_llvm
Nikita Popov 783301298f Don't use usub.with.overflow intrinsic
The canonical form of a usub.with.overflow check in LLVM are
separate sub + icmp instructions, rather than a usub.with.overflow
intrinsic. Using usub.with.overflow will generally result in worse
optimization potential.

The backend will attempt to form usub.with.overflow when it comes
to actual instruction selection. This is not fully reliable, but
I believe this is a better tradeoff than using the intrinsic in
IR.

Fixes #103285.
2022-10-20 12:47:17 +02:00
..
src Don't use usub.with.overflow intrinsic 2022-10-20 12:47:17 +02:00
Cargo.toml Auto merge of #99324 - reez12g:issue-99144, r=jyn514 2022-10-06 03:01:57 +00:00
README.md mv compiler to compiler/ 2020-08-30 18:45:07 +03:00

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.