rust/compiler/rustc_codegen_ssa/src/mir, branch try

Ban projecting into SIMD types [MCP838]

2025-07-20T17:22:09+00:00

Allow `Rvalue::Repeat` to return true in `rvalue_creates_operand` too

2025-07-20T03:50:02+00:00

The conversation in 143502 made be realize how easy this is to handle, since the only possibilty is ZSTs -- everything else ends up with the destination being `LocalKind::Memory` and thus doesn't call `codegen_rvalue_operand` at all. This gets us perilously close to a world where `rvalue_creates_operand` only ever returns true. I'll try out such a world next :)

Auto merge of #143784 - scottmcm:enums-again-new-ex2, r=dianqk

2025-07-19T08:03:40+00:00

Simplify discriminant codegen for niche-encoded variants which don't wrap across an integer boundary Inspired by rust-lang/rust#139729, this attempts to be a much-simpler and more-localized change while still making a difference. (Specifically, this does not try to solve the problem with select-sinking, leaving that to be fixed by https://github.com/llvm/llvm-project/issues/134024 -- once it gets released -- instead of in rustc's codegen.) What this *does* improve is checking for the variant in a 3+ variant enum when that variant is the type providing the niche. Something like `if let Foo::WithBool(_) = ...` previously compiled to `ugt(add(x, -2), 2)`, which is non-trivial to think about because it's depending on the unsigned wrapping to shift the 0/1 up above 2. With this PR it compiles to just `ult(x, 2)`, which is probably what you'd have written yourself if you were doing it by hand to look for "is this byte a bool?". That's done by leaving most of the codegen alone, but adding a couple new special cases to the `is_niche` check. The default looks at the relative discriminant, but in the common cases where there's no wraparound involved, we can just check the original value, rather than the offsetted one. The first commit just adds some tests, so the best way to see the effect of this change is to look at the second commit and how it updates the test expectations.

use `codegen_instance_attrs` where an instance is (easily) available

2025-07-16T21:24:32+00:00

add `codegen_instance_attrs` query

2025-07-16T19:38:58+00:00

and use it for naked functions

Improve comments inside `codegen_get_discr`

2025-07-16T05:30:46+00:00

Simplify codegen for niche-encoded variant tests

2025-07-12T11:53:24+00:00

Auto merge of #143766 - matthiaskrgr:rollup-0x7t69s, r=matthiaskrgr

2025-07-12T07:44:04+00:00

Rollup of 8 pull requests Successful merges: - rust-lang/rust#142391 (rust: library: Add `setsid` method to `CommandExt` trait) - rust-lang/rust#143302 (`tests/ui`: A New Order [27/N]) - rust-lang/rust#143303 (`tests/ui`: A New Order [28/28] FINAL PART) - rust-lang/rust#143568 (std: sys: net: uefi: tcp4: Add timeout support) - rust-lang/rust#143611 (Mention more APIs in `ParseIntError` docs) - rust-lang/rust#143661 (chore: Improve how the other suggestions message gets rendered) - rust-lang/rust#143708 (fix: Include frontmatter in -Zunpretty output ) - rust-lang/rust#143718 (Make UB transmutes really UB in LLVM) r? `@ghost` `@rustbot` modify labels: rollup try-job: i686-gnu-nopt-1 try-job: test-various

Rollup merge of #143718 - scottmcm:ub-transmute-is-ub, r=WaffleLapkin

2025-07-11T05:35:22+00:00

Make UB transmutes really UB in LLVM Ralf suggested in that UB transmutes shouldn't be trapping, which happened for the one path *that* PR was changing, but there's another path as well, so *this* PR changes that other path to match. r? codegen

Auto merge of #142911 - mejrs:unsized, r=compiler-errors

2025-07-11T05:27:32+00:00

Remove support for dynamic allocas Followup to rust-lang/rust#141811