Rollup of 10 pull requests - #161719
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I wasn't able to find a test that verifies different behavior based on whether or not overflow checks are available, so add one here.
…ing methods Newly implemented/adjusted: - vectored read/write - file locking - native paths (bin/tmp) - command output - process pid
Change from the existing behavior of panicking unconditionally to panicking only if debug assertions are enabled, wrapping otherwise. This is more consistent with other operations, and gives slightly better codegen [1]. Suggested in the stabilization PR, RUST-161015. [1]: https://rust.godbolt.org/z/Yz81zhbno
…crum dirfd dir operations (3/4) Previous PR: rust-lang#150679 Reference: rust-lang#139514 Tracking issue: rust-lang#120426
add crashtests [6/N] Followup to rust-lang#161166. [Link to issue list.](https://github.com/rust-lang/rust/issues?q=is:issue%20state:open%20label:I-ICE%20label:S-has-mcve%20sort:created-asc%20AND%20(%20138262%20OR%20142155%20OR%20144241%20OR%20149562%20OR%20152414%20OR%20152416%20OR%20152626%20OR%20154903%20OR%20154963%20OR%20155053%20OR%20156101%20OR%20156288%20))
library: motor: bump moto-rt ABI ver to 17 Newly added features: - vectored read/write - file locking - native paths (bin/tmp/home) - command output - process pid
interpret: fix after_local_read handling `after_local_read` handling was wrong in two ways: - Contrary to what was documented, we invoked it for all reads of locals, not just reads of locals that have their values stored as immediates (without memory). - Miri effectively ignored the `frame` we are passing to it. And indeed we never want this called on anything but the current frame, also for consistency with the corresponding write hook. So let's restrict `local_to_op` to the current frame. Debuggers/visualizers should be able to use the existing method on `LocalState` that Miri also needs for its provenance visitor. Its name was not sufficiently scary for skipping access hooks, so I also overhauled how we name these "fake"/"ghost" access related APIs.
Update books ## rust-lang/reference 3 commits in eda708334abad285d63bc1f3558a51e8b790346e..3b38834b39f732c64686f7c64aa29dcf3cd83ba5 2026-08-18 23:36:42 UTC to 2026-08-18 21:58:44 UTC - Tolerate malformed comments in shebang lookahead (rust-lang/reference#2331) - Fix some lexer rules (rust-lang/reference#2330) - Add grammar validation tool (rust-lang/reference#2325)
Rework `div_ceil` for nonzero integers
This changes the definition of `NonZero::div_ceil` for improved performance by employing a different algorithm.
The generated assembly is better in nearly every case, with the exception of the division by a constant 2, which gains one instruction.
<details>
<summary>Assembly</summary>
```asm
div_ceil_16_new:
lea rax, [rdi - 1]
shr rax, 4
inc rax
ret
div_ceil_16_old:
mov rax, rdi
shr rax, 4
and edi, 15
cmp rdi, 1
sbb rax, -1
ret
div_ceil_21_new:
lea rcx, [rdi - 1]
movabs rdx, -8784163844623596007
mov rax, rcx
mul rdx
sub rcx, rdx
shr rcx
add rcx, rdx
shr rcx, 4
inc rcx
mov rax, rcx
ret
div_ceil_21_old:
movabs rcx, -8784163844623596007
mov rax, rdi
mul rcx
movabs rcx, -3513665537849438403
imul rcx, rdi
sub rdi, rdx
shr rdi
add rdi, rdx
shr rdi, 4
movabs rdx, 878416384462359600
xor eax, eax
cmp rcx, rdx
seta al
add rax, rdi
ret
div_ceil_2_new:
lea rax, [rdi - 1]
shr rax
inc rax
ret
div_ceil_2_old:
mov rax, rdi
mov rcx, rdi
shr rcx
sub rax, rcx
ret
div_ceil_3_new:
lea rax, [rdi - 1]
movabs rcx, -6148914691236517205
mul rcx
shr rdx
lea rax, [rdx + 1]
ret
div_ceil_3_old:
mov rax, rdi
movabs rcx, -6148914691236517205
mul rcx
shr rdx
movabs rsi, 6148914691236517205
xor ecx, ecx
cmp rax, rsi
seta cl
add rcx, rdx
mov rax, rcx
ret
div_ceil_generic_new:
mov rax, rdi
dec rax
mov rcx, rax
or rcx, rsi
shr rcx, 32
je .LBB8_1
xor edx, edx
div rsi
inc rax
ret
.LBB8_1:
xor edx, edx
div esi
inc rax
ret
div_ceil_generic_old:
mov rax, rdi
mov rcx, rdi
or rcx, rsi
shr rcx, 32
je .LBB9_1
xor edx, edx
div rsi
cmp rdx, 1
sbb rax, -1
ret
.LBB9_1:
xor edx, edx
div esi
cmp rdx, 1
sbb rax, -1
ret
```
</details>
It is theoretically possible to adapt this algorithm for normal unsigned integers and possibly even signed normal integers,
but the results were questionable at best, which is why the change was restricted to unsigned nonzero integers.
core: Make funnel shifts panic only if overflow checks are enabled Change from the existing behavior of panicking unconditionally to panicking only if overflow checks are enabled, wrapping otherwise. This is more consistent with other operations, and gives slightly better codegen https://rust.godbolt.org/z/Yz81zhbno. Suggested in the stabilization PR at rust-lang#161015 (comment). The first commit adds some simple tests for overflow behavior that I couldn't find existing anywhere else.
…, r=tgross35 run `classify-runtime-const` test for `f128` This seems to work now, at least locally on linux and windows-gnu. @bors try jobs=test-various,aarch64-apple-*,*-gnu-nopt-*,x86_64-mingw-*,aarch64-msvc-*,arm-android
…ouxu renovate: add lockfile update warning
…, r=ytmimi Stop rustfmt deleting attributes in fn params Currently, rustfmt deletes attributes in function type parameters, for example: ```rust type F = fn(#[rustc_splat] ()); ``` Becomes: ```rust type F = fn(()); ``` [Playground](https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=f56e4727022f44a6e5c937c1521830f9) This is an annoying and confusing bug, and causes formatted code to silently change meaning, or fail compilation. This PR cherry-picks the fix and tests from rust-lang/rustfmt#6590 to `rust-lang/rust`. We're discussing a potential beta backport in [Zulip #t-rustfmt > Attributes in fn type deleted on stable but not nightly](https://rust-lang.zulipchat.com/#narrow/channel/357797-t-rustfmt/topic/Attributes.20in.20fn.20type.20deleted.20on.20stable.20but.20not.20nightly/with/618688539), which is why this PR is separate to the subtree sync. Tracking issue: rust-lang#153629 - This formatting bug impacts splatted function pointers - We just published [a "call for experiment" blog post](https://blog.rust-lang.org/inside-rust/2026/08/19/overloading-experiment/), including experiments with splatted function pointers r? @ytmimi
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Rollup of 10 pull requests try-job: dist-various-1 try-job: test-various try-job: x86_64-gnu-aux try-job: x86_64-gnu-llvm-21-3 try-job: x86_64-msvc-1 try-job: aarch64-apple-1 try-job: aarch64-apple-2 try-job: x86_64-mingw-1 try-job: i686-msvc-1 try-job: i686-msvc-2
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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 9bb55c8 (parent) -> 26747db (this PR) Test differencesShow 4435 test diffsStage 1
Stage 2
Additionally, 4374 doctest diffs were found. These are ignored, as they are noisy. Job group index
Test dashboardRun cargo run --manifest-path src/ci/citool/Cargo.toml -- \
test-dashboard 26747db4f50d83f3670834410ac16fbd39c14c15 --output-dir test-dashboardAnd then open Job duration changes
How to interpret the job duration changes?Job durations can vary a lot, based on the actual runner instance |
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📌 Perf builds for each rolled up PR:
parent commit: 9bb55c8c86 In the case of a perf regression, run the following command for each PR you suspect might be the cause: |
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|
Finished benchmarking commit (26747db): comparison URL. Overall result: no relevant changes - no action needed@rustbot label: -perf-regression Instruction countThis perf run didn't have relevant results for this metric. Max RSS (memory usage)Results (primary -5.3%, secondary -3.7%)A less reliable metric. May be of interest, but not used to determine the overall result above.
CyclesResults (primary 2.7%, secondary -6.4%)A less reliable metric. May be of interest, but not used to determine the overall result above.
Binary sizeThis perf run didn't have relevant results for this metric. Bootstrap: 476.471s -> 471.198s (-1.11%) |
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Successful merges:
div_ceilfor nonzero integers #160819 (Reworkdiv_ceilfor nonzero integers)classify-runtime-consttest forf128#161591 (runclassify-runtime-consttest forf128)r? @ghost
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