rust/compiler/rustc_codegen_ssa/src, branch beta

Auto merge of #145186 - camsteffen:assoc-impl-kind, r=petrochenkov

2025-09-13T13:59:48+00:00

Make `AssocItem` aware of its impl kind The general goal is to have fewer query dependencies by making `AssocItem` aware of its parent impl kind (inherent vs. trait) without having to query the parent def_kind. See individual commits.

Introduce trait_item_of

2025-09-12T20:10:30+00:00

Add --print target-spec-json-schema

2025-09-12T18:53:28+00:00

This schema is helpful for people writing custom target spec JSON. It can provide autocomplete in the editor, and also serves as documentation when there are documentation comments on the structs, as `schemars` will put them in the schema.

Rollup merge of #144549 - folkertdev:va-arg-arm, r=saethlin

2025-09-12T10:02:10+00:00

match clang's `va_arg` assembly on arm targets tracking issue: https://github.com/rust-lang/rust/issues/44930 For this example ```rust #![feature(c_variadic)] #[unsafe(no_mangle)] unsafe extern "C" fn variadic(a: f64, mut args: ...) -> f64 { let b = args.arg::(); let c = args.arg::(); a + b + c } ``` We currently generate (via llvm): ```asm variadic: sub sp, sp, #12 stmib sp, {r2, r3} vmov d0, r0, r1 add r0, sp, #4 vldr d1, [sp, #4] add r0, r0, #15 bic r0, r0, #7 vadd.f64 d0, d0, d1 add r1, r0, #8 str r1, [sp] vldr d1, [r0] vadd.f64 d0, d0, d1 vmov r0, r1, d0 add sp, sp, #12 bx lr ``` LLVM is not doing a good job. In fact, it's well-known that LLVM's implementation of `va_arg` is kind of bad, and we implement it ourselves (based on clang) for many targets already. For arm, our own `emit_ptr_va_arg` saves 3 instructions. Next, it turns out it's important for LLVM to explicitly start and end the lifetime of the `va_list`. In https://github.com/rust-lang/rust/pull/146059 I already end the lifetime, but when looking at this again, I noticed that it is important to also start it, see https://godbolt.org/z/EGqvKTTsK: failing to explicitly start the lifetime uses an extra register. So, the combination of `emit_ptr_va_arg` with starting/ending the lifetime makes rustc emit exactly the instructions that clang generates:: ```asm variadic: sub sp, sp, #12 stmib sp, {r2, r3} vmov d16, r0, r1 vldr d17, [sp, #4] vadd.f64 d16, d16, d17 vldr d17, [sp, #12] vadd.f64 d16, d16, d17 vmov r0, r1, d16 add sp, sp, #12 bx lr ``` The arguments to `emit_ptr_va_arg` are based on [the clang implementation](https://github.com/llvm/llvm-project/blob/03dc2a41f3d9a500e47b513de5c5008c06860d65/clang/lib/CodeGen/Targets/ARM.cpp#L798-L844). r? ``@workingjubilee`` (I can re-roll if your queue is too full, but you do seem like the right person here) try-job: armhf-gnu

Rollup merge of #146209 - bjorn3:lto_refactors5, r=dianqk

2025-09-07T18:02:27+00:00

Misc LTO cleanups Follow up to https://github.com/rust-lang/rust/pull/145955. * Remove want_summary argument from `prepare_thin`. Since https://github.com/rust-lang/rust/pull/133250 ThinLTO summary writing is instead done by `llvm_optimize`. * Two minor cleanups

Rollup merge of #146254 - yotamofek:pr/itertools-all-equal-value, r=cjgillot

2025-09-07T06:18:59+00:00

Use `Itertools::all_equal_value()` where applicable Just a small cleanup. We already have `itertools` as a dep in these crates, so might as well use another of its features. Makes the code simpler IMHO :)

Move timers into execute_*_work_item

2025-09-06T18:37:23+00:00

Remove want_summary argument from prepare_thin

2025-09-06T18:37:23+00:00

It is always false nowadays. ThinLTO summary writing is instead done by llvm_optimize.

Remove thin_link_data method from ThinBufferMethods

2025-09-06T18:37:23+00:00

It is only used within cg_llvm.

Ensure fat LTO doesn't merge everything into the allocator module

2025-09-06T13:31:41+00:00