Rollup of 10 pull requests by JonathanBrouwer · Pull Request #162918 · rust-lang/rust

JonathanBrouwer · 2026-09-17T18:18:15Z

Successful merges:

core::num::f16b Rust's 16bit Brain Float #160859 (core::num::f16b Rust's 16bit Brain Float)
fix is_single_fp_element for s390x and x86 #161987 (fix is_single_fp_element for s390x and x86)
Replace hard linked metadata.rmeta with a copy when finalizing the incremental compilation session dir fails #162366 (Replace hard linked metadata.rmeta with a copy when finalizing the incremental compilation session dir fails)
RISC-V: Add Zmmul target feature #162552 (RISC-V: Add Zmmul target feature)
Ensure concurrent rustc instances in the same process correctly lock the session dir #162602 (Ensure concurrent rustc instances in the same process correctly lock the session dir)
Remove one remaining use of Level::Help #162885 (Remove one remaining use of Level::Help)
c-b: Export fmaf16 now that we have an implementation #162606 (c-b: Export fmaf16 now that we have an implementation)
rustc_{codegen_,}llvm: adapt to new ThreadModel API #162817 (rustc_{codegen_,}llvm: adapt to new ThreadModel API)
Avoid derive edits on macro-generated types #162895 (Avoid derive edits on macro-generated types)
Error on invalid placements of the cfi_encoding attribute. #162899 (Error on invalid placements of the cfi_encoding attribute.)

LLVM 24 has moved from TargetOptions::ThreadModel to specifying thread-model as a module flag. This catches us up.

This copy will retain and is specialized for blocking operations.

Incr comp only uses the non-blocking variant.

This lock registry allows emulating fd based locks (like flock()) on top of the fcntl(F_SETLK) process based locks, thereby ensuring that concurrent rustc instances inside the same process don't break the incr comp locking scheme.

Borrow checking produces some weird, spanless help messages about fixing lifetime errors. If there are multiple, they are grouped under a header like this: ``` help: the following changes may resolve your lifetime errors ``` There are three forms of these. One of the forms is this: ``` = help: add bound `'a: 'b` ``` This form is redundant, because there is always an earlier help note (on a proper error message with a span) like this: ``` = help: consider adding the following bound: `'b: 'a` ``` This commit removes these redundant messages.

…ostic It's currently a spanless top-level help diagnostic. This commit changes it to an error (with one or more help subdiagnostics), gives it a span, and changes the wording. Note that giving it a span means that deduplication will no longer erroneously hide diagnostics with identical wording from different functions! Because of this, several "duplicate diagnostic" mentions are removed from the expected outputs. It's still a weird diagnostic (and now counts towards the error count) but it's better than before. This also removes the one use of buffered non-error diagnostics. So `BufferedDiag` is also removed.

And remove `struct_help`, to discourage use of `Level::Help`. (`Sublevel::Help` is fine.)

If `fmaf16` is exported, the existing version hits errors like: error: `compiler_builtins` cannot call functions through upstream monomorphizations; encountered invalid call from `core::fmt::num::<impl core::fmt::Debug for u64>::fmt` to `core::fmt::num::imp::<impl core::fmt::Display for u64>::fmt` --> library/core/src/fmt/num.rs:85:17 | 79 | / macro_rules! impl_Debug { 80 | | ($($T:ident)*) => { 81 | | $( 82 | | #[stable(feature = "rust1", since = "1.0.0")] ... | 85 | | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ... | 96 | | }; 97 | | } | |_- in this expansion of `impl_Debug!` ... 595 | / impl_Debug! { 596 | | i8 i16 i32 i64 i128 isize 597 | | u8 u16 u32 u64 u128 usize 598 | | } | |_- in this macro invocation Presumably this comes from the call to `panicking::assert_failed!` that needs to be monomorphized. Avoid any formatting by using a plain `debug_assert!` if we are building the crate as compiler-builtins.

LLVM doesn't currently emit this but probably should, and this is valuable as a fallback in any case.

…ertdev,tgross35 `core::num::f16b` Rust's 16bit Brain Float Implements the [RFC: f16b type](rust-lang/rfcs#3983). Best reviewed commit by commit, happy to split into separate PRs if that is deemed easier to review. However the line count and surface area is, in my opinion, reasonably small. Adds; - ABI plumbing for the `f16b` along with `bfloat` lang item to work with LLVM, GCC is explicitly `unimplemented!(...)` - `f16b` feature gate, page for `f16b` on libruscdoc and a `struct bf16` in `core::num` - Tests - Treat `f16b` as a scalar primitive for scalable vectors Issues; - [Tracking Issue](rust-lang#160630) - [RFC](rust-lang/rfcs#3983)

JonathanBrouwer · 2026-09-17T18:18:36Z

@bors r+ p=1

Trying commonly failed jobs
@bors try jobs=dist-various-1,test-various,test-x86_64-gnu-aux,test-x86_64-gnu-llvm-21-3,test-x86_64-msvc-1,test-aarch64-apple-1,test-aarch64-apple-2,test-x86_64-mingw-1,test-i686-msvc,test-armhf-gnu

rust-bors · 2026-09-17T18:18:39Z

📌 Commit 9edabb4 has been approved by JonathanBrouwer

It is now in the queue for this repository.

Rollup of 10 pull requests try-job: dist-various-1 try-job: test-various try-job: test-x86_64-gnu-aux try-job: test-x86_64-gnu-llvm-21-3 try-job: test-x86_64-msvc-1 try-job: test-aarch64-apple-1 try-job: test-aarch64-apple-2 try-job: test-x86_64-mingw-1 try-job: test-i686-msvc try-job: test-armhf-gnu

rust-log-analyzer · 2026-09-17T18:25:42Z

The job test-pr-check-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[RUSTC-TIMING] rustc_hir_analysis test:false 8.214
    Checking rustc_hir_typeck v0.0.0 (/checkout/compiler/rustc_hir_typeck)
[RUSTC-TIMING] rustc_mir_build test:false 3.784
    Checking rustc_traits v0.0.0 (/checkout/compiler/rustc_traits)
error[E0004]: non-exhaustive patterns: `rustc_abi::Primitive::Float(rustc_abi::Float::F16B)` not covered
    --> compiler/rustc_codegen_llvm/src/va_arg.rs:480:50
     |
 480 |             BackendRepr::Scalar(scalar) => match scalar.primitive() {
     |                                                  ^^^^^^^^^^^^^^^^^^ pattern `rustc_abi::Primitive::Float(rustc_abi::Float::F16B)` not covered
     |
note: `rustc_abi::Primitive` defined here
    --> compiler/rustc_abi/src/lib.rs:1498:1
     |
1498 | pub enum Primitive {
     | ^^^^^^^^^^^^^^^^^^
...
1507 |     Float(Float),
     |     ----- not covered
     = note: the matched value is of type `rustc_abi::Primitive`
help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
     |
 483 ~                 Primitive::Int(_, _) | Primitive::Pointer(_) => false,
 484 ~                 rustc_abi::Primitive::Float(rustc_abi::Float::F16B) => todo!(),
     |

For more information about this error, try `rustc --explain E0004`.
[RUSTC-TIMING] rustc_codegen_llvm test:false 3.712
error: could not compile `rustc_codegen_llvm` (lib) due to 1 previous error

rust-log-analyzer · 2026-09-17T18:29:10Z

The job test-x86_64-gnu-aux failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[RUSTC-TIMING] rustc_lint test:false 59.165
   Compiling rustc_ty_utils v0.0.0 (/checkout/compiler/rustc_ty_utils)
[RUSTC-TIMING] rustc_const_eval test:false 54.444
   Compiling rustc_mir_transform v0.0.0 (/checkout/compiler/rustc_mir_transform)
error[E0004]: non-exhaustive patterns: `rustc_abi::Primitive::Float(rustc_abi::Float::F16B)` not covered
    --> compiler/rustc_codegen_llvm/src/va_arg.rs:480:50
     |
 480 |             BackendRepr::Scalar(scalar) => match scalar.primitive() {
     |                                                  ^^^^^^^^^^^^^^^^^^ pattern `rustc_abi::Primitive::Float(rustc_abi::Float::F16B)` not covered
     |
note: `rustc_abi::Primitive` defined here
    --> compiler/rustc_abi/src/lib.rs:1498:1
     |
1498 | pub enum Primitive {
     | ^^^^^^^^^^^^^^^^^^
...
1507 |     Float(Float),
     |     ----- not covered
     = note: the matched value is of type `rustc_abi::Primitive`
help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
     |
 483 ~                 Primitive::Int(_, _) | Primitive::Pointer(_) => false,
 484 ~                 rustc_abi::Primitive::Float(rustc_abi::Float::F16B) => todo!(),
     |

For more information about this error, try `rustc --explain E0004`.
[RUSTC-TIMING] rustc_codegen_llvm test:false 3.550
error: could not compile `rustc_codegen_llvm` (lib) due to 1 previous error
---
Currently active steps:
compile::Assemble { target_compiler: Compiler { stage: 1, host: x86_64-unknown-linux-gnu, forced_compiler: false } } at src/bootstrap/src/core/build_steps/tool.rs:375
compile::Rustc { target: x86_64-unknown-linux-gnu, build_compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, crates: [] } at src/bootstrap/src/core/build_steps/compile.rs:2328
Build completed unsuccessfully in 0:05:56
make: *** [Makefile:51: check-aux] Error 1
  local time: Thu Sep 17 18:28:58 UTC 2026
  network time: Thu, 17 Sep 2026 18:28:58 GMT
##[error]Process completed with exit code 2.
##[group]Run echo "disk usage:"
echo "disk usage:"

rust-bors · 2026-09-17T18:29:10Z

PR #160859, which is a member of this rollup, was unapproved.

This rollup was thus unapproved.

rust-bors · 2026-09-17T19:06:44Z

💔 Test for a5598e9 failed: CI. Failed jobs:

try - dist-various-1 (web logs, enhanced plaintext logs)
try - test-aarch64-apple-1 (web logs, enhanced plaintext logs)
try - test-aarch64-apple-2 (web logs, enhanced plaintext logs)
try - test-armhf-gnu (web logs, enhanced plaintext logs)
try - test-i686-msvc (web logs, enhanced plaintext logs)
(and 5 other jobs)

TechnoPorg and others added 30 commits September 9, 2026 15:36

RISC-V: Add zmmul target feature

0c8e360

Document interaction between "m" and "zmmul"

7a6e24a

Tweak wording of comment in target_features.rs

d609aff

Address review comments

a33e6eb

add non_zst_field helper

aadf13c

fix is_single_fp_element for s390x and x86

ee524a2

abi/compatibility test: add simple float type tests

33871b9

rustc_{codegen_,}llvm: adapt to new ThreadModel API

5dd4631

LLVM 24 has moved from TargetOptions::ThreadModel to specifying thread-model as a module flag. This catches us up.

Copy metadata workproduct when session dir rename fails

3c283d4

Gate finalize_session_directory rename fallbacks to windows

26e7e77

Pass File to Fallback::lock

b4beb1e

Have a separate copy of the flock code for rustdoc

0143ce1

This copy will retain and is specialized for blocking operations.

Remove wait argument from Lock::new

435b07d

Incr comp only uses the non-blocking variant.

Move metadata work product name into a constant

0bae8cf

Clarify Level::{Help,Note,FailureNote} details

31fafe3

And remove `struct_help`, to discourage use of `Level::Help`. (`Sublevel::Help` is fine.)

c-b: Export fmaf16 now that we have an implementation

362d116

LLVM doesn't currently emit this but probably should, and this is valuable as a fallback in any case.

f16b Implementation and documentation

db58d50

Add F16B to Float enum & wireup trivial matches

ef2c67f

Wire up f16b in backends

ddab56a

Update Tidy rules to allow for //@ revision

dcf9ab4

Update and write tests

4ff2c1d

Use HashMap::entry

2be177e

Add regression tests for derive suggestions on generated enums

3c8dcac

Avoid derive edits on macro-generated types

4a1b4b0

Error on invalid uses of the cfi_encoding attribute.

9600948

rust-bors Bot added the rollup A PR which is a rollup label Sep 17, 2026

rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 17, 2026

This comment has been minimized.

Sign in to view

JonathanBrouwer mentioned this pull request Sep 17, 2026

core::num::f16b Rust's 16bit Brain Float #160859

Open

rust-bors Bot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Sep 17, 2026

JonathanBrouwer closed this Sep 17, 2026

rustbot removed the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label Sep 17, 2026

rust-bors Bot added the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label Sep 17, 2026

Navigation Menu

Uh oh!

Rollup of 10 pull requests - #162918

Rollup of 10 pull requests#162918
JonathanBrouwer wants to merge 39 commits into
rust-lang:mainfrom
JonathanBrouwer:rollup-sJ7H4ui

JonathanBrouwer commented Sep 17, 2026

Uh oh!

JonathanBrouwer commented Sep 17, 2026

Uh oh!

rust-bors Bot commented Sep 17, 2026

Uh oh!

This comment has been minimized.

rust-log-analyzer commented Sep 17, 2026

Uh oh!

rust-log-analyzer commented Sep 17, 2026

Uh oh!

rust-bors Bot commented Sep 17, 2026

Uh oh!

rust-bors Bot commented Sep 17, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

14 participants

Uh oh!

Conversation

JonathanBrouwer commented Sep 17, 2026

Uh oh!

JonathanBrouwer commented Sep 17, 2026

Uh oh!

rust-bors Bot commented Sep 17, 2026

Uh oh!

This comment has been minimized.

rust-log-analyzer commented Sep 17, 2026

Uh oh!

rust-log-analyzer commented Sep 17, 2026

Uh oh!

rust-bors Bot commented Sep 17, 2026

Uh oh!

rust-bors Bot commented Sep 17, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

14 participants