Merge three `MaxUniverse`s into one by adwinwhite · Pull Request #158951 · rust-lang/rust

adwinwhite · 2026-07-08T08:26:19Z

We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both.

I think this is a small refactor without any behavior impact.
r? @ShoyuVanilla or @khyperia

rustbot · 2026-07-08T08:26:23Z

changes to the core type system

cc @lcnr

rustbot · 2026-07-08T08:26:25Z

ShoyuVanilla is currently at their maximum review capacity.
They may take a while to respond.

adwinwhite · 2026-07-08T08:27:43Z

Wonder whether the resolve_vars_if_possible causes perf regression.
@bors try @rust-timer queue

Merge three `MaxUniverse`s into one

rust-bors · 2026-07-08T10:34:40Z

☀️ Try build successful (CI)
Build commit: d38b46e (d38b46ead03071b39dde8bbe959f68f764519d6b)
Base parent: 99576cf (99576cf2ebc870c305225e9856b9423228872c56)

rust-timer · 2026-07-08T12:27:09Z

Finished benchmarking commit (d38b46e): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This perf run didn't have relevant results for this metric.

Max RSS (memory usage)

Results (secondary 4.4%)

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)	4.4%	[4.4%, 4.4%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Cycles

This perf run didn't have relevant results for this metric.

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 488.508s -> 490.004s (0.31%)
Artifact size: 388.95 MiB -> 388.46 MiB (-0.13%)

ShoyuVanilla

@bors r+ rollup

View changes since this review

rust-bors · 2026-07-08T12:30:35Z

📌 Commit 1818498 has been approved by ShoyuVanilla

It is now in the queue for this repository.

@ShoyuVanilla

…hoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

…uwer Rollup of 18 pull requests Successful merges: - #158871 (add relnotes for 1.97.0) - #150946 (intrinsics: Add a fallback for non-const libm float functions) - #158617 (allow mGCA const arguments to fall back to anon consts) - #158645 (Fix splat ICEs and ban it in closures) - #158655 (Fix coroutine MIR saved local remapping) - #158666 (Carry the `b_offset` inside `BackendRepr::ScalarPair`) - #158920 (Update wasm-component-ld to 0.5.26) - #158926 (wrapping_sh* methods: clarify underspecified reference) - #158927 (add core test run with `-Zforce-intrinsic-fallback`) - #151379 (Stabilize `VecDeque::retain_back` from `truncate_front`) - #158807 (Add regression test for CString::clone_into unwind safety) - #158862 (Fix the span for parameter suggestion ) - #158883 (tests: fix enum-match.rs to handle LLVM 23) - #158894 (Make the ordering of non-terminal binds in ambiguity error messages deterministic) - #158902 (add codegen test for range length bound propagation) - #158913 (Update `browser-ui-test` version to `0.24.1`) - #158935 (std: support real fd methods on Emscripten) - #158951 (Merge three `MaxUniverse`s into one)

@ShoyuVanilla

…hoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

…uwer Rollup of 17 pull requests Successful merges: - #158510 (Enable `static_position_independent_executables` on all gnu and musl targets) - #158541 (Move `std::io::Write` to `core::io`) - #158899 (Fix `unaligned_volatile_store` by removing `MemFlags::UNALIGNED`) - #155429 (Support `u128`/`i128` c-variadic arguments) - #156370 (Reject linked dylib EII default overrides) - #157153 (allow `Allocator`s to be used as `#[global_allocator]`s) - #158535 (Support `#[track_caller]` on EII declarations) - #158617 (allow mGCA const arguments to fall back to anon consts) - #158645 (Fix splat ICEs and ban it in closures) - #158988 (Redo `TokenStreamIter`) - #158347 (Improve generic parameters handling for #[diagnostic::on_const]) - #158722 (delegation: do not always inherit `ConstArgHasType` predicates) - #158739 (view-types: HIR lowering) - #158883 (tests: fix enum-match.rs to handle LLVM 23) - #158886 (Add documentation for the `no_std` attribute) - #158951 (Merge three `MaxUniverse`s into one) - #158961 (Reapply "LLVM 23: Run AssignGUIDPass in some places")

@ShoyuVanilla

…hoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

@ShoyuVanilla

…hoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

@ShoyuVanilla

…hoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

…uwer Rollup of 21 pull requests Successful merges: - #150946 (intrinsics: Add a fallback for non-const libm float functions) - #158510 (Enable `static_position_independent_executables` on all gnu and musl targets) - #158541 (Move `std::io::Write` to `core::io`) - #158899 (Fix `unaligned_volatile_store` by removing `MemFlags::UNALIGNED`) - #155429 (Support `u128`/`i128` c-variadic arguments) - #156370 (Reject linked dylib EII default overrides) - #156508 (Infer all anonymous lifetimes in assoc consts as `'static`) - #158617 (allow mGCA const arguments to fall back to anon consts) - #158645 (Fix splat ICEs and ban it in closures) - #158859 (Improve `-Zls` diagnostic message on `.rs` files) - #158988 (Redo `TokenStreamIter`) - #158347 (Improve generic parameters handling for #[diagnostic::on_const]) - #158722 (delegation: do not always inherit `ConstArgHasType` predicates) - #158739 (view-types: HIR lowering) - #158883 (tests: fix enum-match.rs to handle LLVM 23) - #158886 (Add documentation for the `no_std` attribute) - #158940 (Implement feature `char_to_u32`) - #158951 (Merge three `MaxUniverse`s into one) - #158961 (Reapply "LLVM 23: Run AssignGUIDPass in some places") - #158996 ([compiler] Implement `PartialOrd` via `Ord` for `Span` and newtype_indexes) - #159005 (Use `as_lang_item` instead of repeatedly matching)

@ShoyuVanilla

…hoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

…uwer Rollup of 24 pull requests Successful merges: - #150946 (intrinsics: Add a fallback for non-const libm float functions) - #158510 (Enable `static_position_independent_executables` on all gnu and musl targets) - #158541 (Move `std::io::Write` to `core::io`) - #158899 (Fix `unaligned_volatile_store` by removing `MemFlags::UNALIGNED`) - #156027 (Consider captured regions for opaque type region liveness.) - #156370 (Reject linked dylib EII default overrides) - #156508 (Infer all anonymous lifetimes in assoc consts as `'static`) - #157561 (rustdoc: do not include extra stuff in span) - #158617 (allow mGCA const arguments to fall back to anon consts) - #158645 (Fix splat ICEs and ban it in closures) - #158859 (Improve `-Zls` diagnostic message on `.rs` files) - #158988 (Redo `TokenStreamIter`) - #158347 (Improve generic parameters handling for #[diagnostic::on_const]) - #158384 (Allow BackwardIncompatibleDropHint in polonius legacy) - #158722 (delegation: do not always inherit `ConstArgHasType` predicates) - #158739 (view-types: HIR lowering) - #158877 (borrowck: Keep returned `path` from `best_blame_constraint()` consistent) - #158883 (tests: fix enum-match.rs to handle LLVM 23) - #158886 (Add documentation for the `no_std` attribute) - #158940 (Implement feature `char_to_u32`) - #158951 (Merge three `MaxUniverse`s into one) - #158961 (Reapply "LLVM 23: Run AssignGUIDPass in some places") - #158995 (Use REST API in linkchecker script) - #158996 ([compiler] Implement `PartialOrd` via `Ord` for `Span` and newtype_indexes)

@ShoyuVanilla

…hoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

Rollup of 24 pull requests Successful merges: - #150946 (intrinsics: Add a fallback for non-const libm float functions) - #158541 (Move `std::io::Write` to `core::io`) - #156027 (Consider captured regions for opaque type region liveness.) - #156370 (Reject linked dylib EII default overrides) - #156508 (Infer all anonymous lifetimes in assoc consts as `'static`) - #157561 (rustdoc: do not include extra stuff in span) - #158617 (allow mGCA const arguments to fall back to anon consts) - #158645 (Fix splat ICEs and ban it in closures) - #158859 (Improve `-Zls` diagnostic message on `.rs` files) - #158988 (Redo `TokenStreamIter`) - #158347 (Improve generic parameters handling for #[diagnostic::on_const]) - #158384 (Allow BackwardIncompatibleDropHint in polonius legacy) - #158722 (delegation: do not always inherit `ConstArgHasType` predicates) - #158739 (view-types: HIR lowering) - #158877 (borrowck: Keep returned `path` from `best_blame_constraint()` consistent) - #158883 (tests: fix enum-match.rs to handle LLVM 23) - #158886 (Add documentation for the `no_std` attribute) - #158940 (Implement feature `char_to_u32`) - #158951 (Merge three `MaxUniverse`s into one) - #158960 (Fix bootstrap submodule path prefix matching) - #158961 (Reapply "LLVM 23: Run AssignGUIDPass in some places") - #158995 (Use REST API in linkchecker script) - #158996 ([compiler] Implement `PartialOrd` via `Ord` for `Span` and newtype_indexes) - #159036 (bootstrap: expand '@argfile' arguments to rustc shim)

@ShoyuVanilla

Rollup merge of #158951 - adwinwhite:unify-max-universe, r=ShoyuVanilla Merge three `MaxUniverse`s into one We have three similar visitors to find the max universe of a value. They differ only in whether they consider infers, placeholders or both. I think this is a small refactor without any behavior impact. r? @ShoyuVanilla or @khyperia

JonathanBrouwer · 2026-07-12T07:44:18Z

@rust-timer build d53d381

rust-timer · 2026-07-12T12:21:03Z

Finished benchmarking commit (d53d381): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.4%	[0.3%, 0.4%]	2
Regressions ❌ (secondary)	0.1%	[0.0%, 0.2%]	9
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.1%	[-0.1%, -0.0%]	3
All ❌✅ (primary)	0.4%	[0.3%, 0.4%]	2

Max RSS (memory usage)

Results (primary -0.7%, secondary -1.8%)

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

	mean	range	count
Regressions ❌ (primary)	2.4%	[2.4%, 2.4%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.7%	[-3.7%, -3.7%]	1
Improvements ✅ (secondary)	-1.8%	[-3.5%, -1.0%]	3
All ❌✅ (primary)	-0.7%	[-3.7%, 2.4%]	2

Cycles

Results (secondary 1.2%)

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)	5.8%	[2.0%, 14.2%]	9
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.3%	[-9.2%, -1.5%]	9
All ❌✅ (primary)	-	-	0

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 490.768s -> 489.423s (-0.27%)
Artifact size: 389.74 MiB -> 389.63 MiB (-0.03%)

JonathanBrouwer · 2026-07-12T20:16:05Z

@rustbot label: +perf-regression-triaged
Noise

Rollup of 24 pull requests Successful merges: - rust-lang/rust#150946 (intrinsics: Add a fallback for non-const libm float functions) - rust-lang/rust#158541 (Move `std::io::Write` to `core::io`) - rust-lang/rust#156027 (Consider captured regions for opaque type region liveness.) - rust-lang/rust#156370 (Reject linked dylib EII default overrides) - rust-lang/rust#156508 (Infer all anonymous lifetimes in assoc consts as `'static`) - rust-lang/rust#157561 (rustdoc: do not include extra stuff in span) - rust-lang/rust#158617 (allow mGCA const arguments to fall back to anon consts) - rust-lang/rust#158645 (Fix splat ICEs and ban it in closures) - rust-lang/rust#158859 (Improve `-Zls` diagnostic message on `.rs` files) - rust-lang/rust#158988 (Redo `TokenStreamIter`) - rust-lang/rust#158347 (Improve generic parameters handling for #[diagnostic::on_const]) - rust-lang/rust#158384 (Allow BackwardIncompatibleDropHint in polonius legacy) - rust-lang/rust#158722 (delegation: do not always inherit `ConstArgHasType` predicates) - rust-lang/rust#158739 (view-types: HIR lowering) - rust-lang/rust#158877 (borrowck: Keep returned `path` from `best_blame_constraint()` consistent) - rust-lang/rust#158883 (tests: fix enum-match.rs to handle LLVM 23) - rust-lang/rust#158886 (Add documentation for the `no_std` attribute) - rust-lang/rust#158940 (Implement feature `char_to_u32`) - rust-lang/rust#158951 (Merge three `MaxUniverse`s into one) - rust-lang/rust#158960 (Fix bootstrap submodule path prefix matching) - rust-lang/rust#158961 (Reapply "LLVM 23: Run AssignGUIDPass in some places") - rust-lang/rust#158995 (Use REST API in linkchecker script) - rust-lang/rust#158996 ([compiler] Implement `PartialOrd` via `Ord` for `Span` and newtype_indexes) - rust-lang/rust#159036 (bootstrap: expand '@argfile' arguments to rustc shim)

unify MaxUniverses

1818498

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. WG-trait-system-refactor The Rustc Trait System Refactor Initiative (-Znext-solver) labels Jul 8, 2026

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rust-bors Bot pushed a commit that referenced this pull request Jul 8, 2026

Auto merge of #158951 - adwinwhite:unify-max-universe, r=<try>

d38b46e

Merge three `MaxUniverse`s into one

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rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Jul 8, 2026

ShoyuVanilla approved these changes Jul 8, 2026

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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 Jul 8, 2026

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Rollup of 18 pull requests #158958

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Rollup of 17 pull requests #159007

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Rollup of 18 pull requests #159013

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Rollup of 21 pull requests #159020

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Rollup of 21 pull requests #159024

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Rollup of 24 pull requests #159037

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Rollup of 25 pull requests #159045

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Rollup of 24 pull requests #159046

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rust-bors Bot merged commit 9a91b8f into rust-lang:main Jul 10, 2026
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rustbot added the perf-regression Performance regression. label Jul 12, 2026

rustbot added the perf-regression-triaged The performance regression has been triaged. label Jul 12, 2026

lcnr mentioned this pull request Jul 14, 2026

Stabilize the next-generation trait solver rust-lang/goals#113

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Merge three `MaxUniverse`s into one - #158951

Merge three `MaxUniverse`s into one#158951
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Overall result: no relevant changes - no action needed

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Overall result: ❌✅ regressions and improvements - please read:

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