GCC backend subtree update #145890

GuillaumeGomez · 2025-08-26T15:26:13Z

r? ghost

…update_cg_gcc_2025-08-04

Fix for m68k

Make sure that compiler and linker don't optimize the section's contents away by adding the global holding the data to "llvm.used". The volatile load in the main shim is retained because "llvm.used", which translates to SHF_GNU_RETAIN on ELF targets, requires a reasonably recent linker; emitting the volatile load ensures compatibility with older linkers, at least when libstd is used. Pretty printers in dylib dependencies are now emitted by the main crate instead of the dylib; apart from matching how rlibs are handled, this approach has the advantage that `omit_gdb_pretty_printer_section` keeps working with dylib dependencies.

This reverts commit 868bdde.

The implementation of the linkage attribute inside extern blocks defines symbols starting with _rust_extern_with_linkage_. If someone tries to also define this symbol you will get a symbol conflict or even an ICE. By adding an unpredictable component to the symbol name, this becomes less of an issue.

atomicrmw on pointers: move integer-pointer cast hacks into backend Conceptually, we want to have atomic operations on pointers of the form `fn atomic_add(ptr: *mut T, offset: usize, ...)`. However, LLVM does not directly support such operations (llvm/llvm-project#120837), so we have to cast the `offset` to a pointer somewhere. This PR moves that hack into the LLVM backend, so that the standard library, intrinsic, and Miri all work with the conceptual operation we actually want. Hopefully, one day LLVM will gain a way to represent these operations without integer-pointer casts, and then the hack will disappear entirely. Cc ```@nikic``` -- this is the best we can do right now, right? Fixes rust-lang#134617

Fmt tests run

Update gccjit dependency and libgccjit commit

…8_14 Sync from rust 2025/08/14

…8_25 Sync from rust 2025/08/25

…update_cg_gcc_2025-08-26

rustbot · 2025-08-26T15:26:19Z

Some changes occurred in compiler/rustc_codegen_gcc

cc @antoyo, @GuillaumeGomez

rustbot · 2025-08-26T16:09:51Z

⚠️ Warning ⚠️

Some commits in this PR modify submodules.

If this was not intentional, see I changed a submodule on accident in the rustc dev guide.

GuillaumeGomez · 2025-08-26T18:53:30Z

@bors r+ p=1

bors · 2025-08-26T18:53:33Z

📌 Commit 92104a6 has been approved by GuillaumeGomez

It is now in the queue for this repository.

bors · 2025-08-26T18:54:50Z

⌛ Testing commit 92104a6 with merge 160e762...

bors · 2025-08-26T22:02:40Z

☀️ Test successful - checks-actions
Approved by: GuillaumeGomez
Pushing 160e762 to master...

github-actions · 2025-08-26T22:05:22Z

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 91ee6a4 (parent) -> 160e762 (this PR)

Test differences

Show 2 test diffs

2 doctest diffs were found. These are ignored, as they are noisy.

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 160e7623e8cbbf1feab2b6e2a24733a98c7bde9c --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

x86_64-gnu-llvm-19: 2611.6s -> 3583.8s (37.2%)
dist-aarch64-linux: 8868.2s -> 6181.3s (-30.3%)
dist-apple-various: 5250.0s -> 4519.3s (-13.9%)
i686-gnu-2: 6247.9s -> 5504.0s (-11.9%)
x86_64-gnu-aux: 7515.0s -> 6632.7s (-11.7%)
i686-gnu-nopt-1: 8413.8s -> 7439.7s (-11.6%)
aarch64-gnu-llvm-19-1: 3714.9s -> 3291.3s (-11.4%)
x86_64-rust-for-linux: 2850.4s -> 2539.0s (-10.9%)
aarch64-gnu-llvm-19-2: 2522.6s -> 2257.6s (-10.5%)
aarch64-msvc-2: 5397.0s -> 4901.6s (-9.2%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

rust-timer · 2025-08-26T23:13:38Z

Finished benchmarking commit (160e762): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (secondary -2.2%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.2%	[-2.2%, -2.1%]	2
All ❌✅ (primary)	-	-	0

Cycles

Results (primary -2.5%, secondary -1.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.5%	[-2.5%, -2.5%]	2
Improvements ✅ (secondary)	-1.9%	[-2.8%, -1.1%]	2
All ❌✅ (primary)	-2.5%	[-2.5%, -2.5%]	2

Binary size

Results (secondary 0.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.0%	[0.0%, 0.0%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Bootstrap: 469.036s -> 466.645s (-0.51%)
Artifact size: 391.17 MiB -> 391.15 MiB (-0.00%)

rust-log-analyzer · 2025-08-27T00:01:29Z

A job failed! Check out the build log: (web) (plain enhanced) (plain)

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

Prepare workflow directory
Prepare all required actions
Getting action download info
Download action repository 'actions/checkout@v5' (SHA:08c6903cd8c0fde910a37f88322edcfb5dd907a8)
Complete job name: DockerHub mirror
##[group]Run actions/checkout@v5
with:
  persist-credentials: false
  repository: rust-lang/rust
  token: ***
---
http.https://github.com/.extraheader
[command]/usr/bin/git config --local --unset-all http.https://github.com/.extraheader
[command]/usr/bin/git submodule foreach --recursive sh -c "git config --local --name-only --get-regexp 'http\.https\:\/\/github\.com\/\.extraheader' && git config --local --unset-all 'http.https://github.com/.extraheader' || :"
##[endgroup]
##[group]Run echo "***" | docker login ghcr.io -u rust-lang --password-stdin
echo "***" | docker login ghcr.io -u rust-lang --password-stdin
shell: /usr/bin/bash -e {0}
##[endgroup]
Error response from daemon: Get "https://ghcr.io/v2/": Get "https://ghcr.io/token?account=rust-lang&client_id=docker&offline_token=true&service=ghcr.io": net/http: request canceled (Client.Timeout exceeded while awaiting headers) (Client.Timeout exceeded while awaiting headers)
##[error]Process completed with exit code 1.
Post job cleanup.

RalfJung and others added 27 commits July 23, 2025 08:32

atomicrmw on pointers: move integer-pointer cast hacks into backend

84f834b

Merge commit '482e8540a1b757ed7bccc2041c5400f051fdb01e' into subtree-…

c4b91bd

…update_cg_gcc_2025-08-04

Reenable m68k CI

1c79360

Remove outdated comment

aa51e18

Merge pull request rust-lang#373 from rust-lang/fix/m68k

f0ab82f

Fix for m68k

Revert "Preserve the .debug_gdb_scripts section"

82aac02

This reverts commit 868bdde.

Update gccjit dependency and libgccjit commit

e22a140

run rustfmt on tests/run/*.rs

307ebca

fix tests/run formatting

dde77db

Merge pull request rust-lang#748 from dvermd/fmt_tests_run

32db0c6

Fmt tests run

Port the #[linkage] attribute to the new attribute system

27beb72

Merge pull request rust-lang#747 from GuillaumeGomez/update

2714314

Update gccjit dependency and libgccjit commit

Merge branch 'master' into sync_from_rust_2025_08_14

ec19410

Update to nightly-2025-08-14

26183d5

Rename/remove some UI and run-make tests

3f476d3

Don't set feature compiler-builtins-no-f16-f128

eff47b5

Complete functionality and general cleanup

e6eb521

Merge pull request rust-lang#751 from rust-lang/sync_from_rust_2025_0…

aac150e

…8_14 Sync from rust 2025/08/14

Merge branch 'master' into sync_from_rust_2025_08_25

02a3cae

Update to nightly-2025-08-25

a53663f

Set default codegen backend to gcc

ad99858

Merge pull request rust-lang#753 from rust-lang/sync_from_rust_2025_0…

feb4282

…8_25 Sync from rust 2025/08/25

Merge commit 'feb42827f11a7ae241ceecc81e9ae556fb6ba214' into subtree-…

1713713

…update_cg_gcc_2025-08-26

Fix sync conflict

a03a0f1

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Aug 26, 2025

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GuillaumeGomez force-pushed the subtree-update_cg_gcc_2025-08-26 branch from 70d06b3 to a03a0f1 Compare August 26, 2025 16:07

Update GCC submodule

92104a6

bors 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 Aug 26, 2025

bors added the merged-by-bors This PR was explicitly merged by bors. label Aug 26, 2025

bors merged commit 160e762 into rust-lang:master Aug 26, 2025
11 checks passed

rustbot added this to the 1.91.0 milestone Aug 26, 2025

GuillaumeGomez deleted the subtree-update_cg_gcc_2025-08-26 branch August 26, 2025 22:06

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Test differences

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Overall result: no relevant changes - no action needed

Instruction count

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Cycles

Binary size

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