nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2024-11-30 10:45:18 +00:00
Code Issues Packages Projects Releases Wiki Activity
fac0a74450
rust/compiler/rustc_codegen_ssa
History
bors 02f7806ecd Auto merge of #124606 - scottmcm:less-expect, r=cjgillot 
Stop `llvm.expect`ing assert terminators

We're putting `llvm.expect` calls before the <https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/mir/enum.TerminatorKind.html#variant.Assert> terminators.

But we don't need them.  One of the arms is always to a panic function that's marked `#[cold]`, which is `cold` <https://llvm.org/docs/LangRef.html#function-attributes> in LLVM, which

> When computing edge weights, basic blocks post-dominated by a cold function call are also considered to be cold; and, thus, given low weight.

So even without us emitting the extra intrinsic call, LLVM knows what to expect for the `br`.  Thus we can save the (small) effort of emitting it and then LLVM optimizing it out.

r? compiler
2024-05-05 01:06:22 +00:00
..
src Auto merge of #124606 - scottmcm:less-expect, r=cjgillot 2024-05-05 01:06:22 +00:00
Cargo.toml Update ar_archive_writer to 0.2.0 2024-04-09 17:45:02 +00:00
messages.ftl Handle calls to upstream monomorphizations in compiler_builtins 2024-03-16 15:22:05 -04:00
README.md mv compiler to compiler/ 2020-08-30 18:45:07 +03:00

README.md

Please read the rustc-dev-guide chapter on Backend Agnostic Codegen.