rust/compiler/rustc_codegen_llvm
bors 039d887928 Auto merge of #119911 - NCGThompson:is-statically-known, r=oli-obk
Replacement of #114390: Add new intrinsic `is_var_statically_known` and optimize pow for powers of two

This adds a new intrinsic `is_val_statically_known` that lowers to [``@llvm.is.constant.*`](https://llvm.org/docs/LangRef.html#llvm-is-constant-intrinsic).` It also applies the intrinsic in the int_pow methods to recognize and optimize the idiom `2isize.pow(x)`. See #114390 for more discussion.

While I have extended the scope of the power of two optimization from #114390, I haven't added any new uses for the intrinsic. That can be done in later pull requests.

Note: When testing or using the library, be sure to use `--stage 1` or higher. Otherwise, the intrinsic will be a noop and the doctests will be skipped. If you are trying out edits, you may be interested in [`--keep-stage 0`](https://rustc-dev-guide.rust-lang.org/building/suggested.html#faster-builds-with---keep-stage).

Fixes #47234
Resolves #114390
`@Centri3`
2024-01-25 05:16:53 +00:00
..
src Auto merge of #119911 - NCGThompson:is-statically-known, r=oli-obk 2024-01-25 05:16:53 +00:00
Cargo.toml Update measureme crate to version 11 2024-01-13 16:32:03 +01:00
messages.ftl warn when using an unstable feature with -Ctarget-feature 2023-11-06 09:44:00 +01:00
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.