do not attempt to prove unknowable goals #129896
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
rustbot
added
S-waiting-on-review
jackh726
approved these changes
Sep 3, 2024
Comment on lines
+671
to
+672
| // We also look for unknowable candidates. In case a goal is unknowable, there's | ||
| // always exactly 1 candidate. |
There was a problem hiding this comment.
It could be good to add an assert below for this.
There was a problem hiding this comment.
there are two possible asserts, both feel quite meh, so I didn't add any:
- if we found a coherence unknowable candidate, assert that there are no other candidates
- if we didn't find one, there is no coherence unknowable candidate in the remaining
candidates
|
☔ The latest upstream changes (presumably #129915) made this pull request unmergeable. Please resolve the merge conflicts. |
lcnr
force-pushed
the
bail-on-unknowable
branch
from
be3821c to
6188aae
Compare
bors
added
S-waiting-on-bors
matthiaskrgr
added a commit
to matthiaskrgr/rust
that referenced
this pull request
Sep 3, 2024
do not attempt to prove unknowable goals In case a goal is unknowable, we previously still checked all other possible ways to prove this goal, even though its final result is already guaranteed to be ambiguous. By ignoring all other candidates in that case we can avoid a lot of unnecessary work, fixing the performance regression in typenum found in rust-lang#121848. This is already the behavior in the old solver. This could in theory cause future-compatability issues as considering fewer goals unknowable may end up causing performance regressions/hangs. I am quite confident that this will not be an issue. r? `@compiler-errors`
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 3, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129706 (Rename dump of coroutine by-move-body to be more consistent, fix ICE in dump_mir) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 3, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129863 (update comment regarding TargetOptions.features) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 3, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129863 (update comment regarding TargetOptions.features) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 4, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129863 (update comment regarding TargetOptions.features) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 4, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129863 (update comment regarding TargetOptions.features) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 4, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129863 (update comment regarding TargetOptions.features) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 4, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129863 (update comment regarding TargetOptions.features) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 4, 2024
…iaskrgr Rollup of 9 pull requests Successful merges: - rust-lang#127692 (Suggest `impl Trait` for References to Bare Trait in Function Header) - rust-lang#128701 (Don't Suggest Labeling `const` and `unsafe` Blocks ) - rust-lang#128934 (Non-exhaustive structs may be empty) - rust-lang#129630 (Document the broken C ABI of `wasm32-unknown-unknown`) - rust-lang#129863 (update comment regarding TargetOptions.features) - rust-lang#129896 (do not attempt to prove unknowable goals) - rust-lang#129926 (Move `SanityCheck` and `MirPass`) - rust-lang#129928 (rustc_driver_impl: remove some old dead logic) - rust-lang#129930 (include 1.80.1 release notes on master) r? `@ghost` `@rustbot` modify labels: rollup
rust-timer
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Sep 5, 2024
Rollup merge of rust-lang#129896 - lcnr:bail-on-unknowable, r=jackh726 do not attempt to prove unknowable goals In case a goal is unknowable, we previously still checked all other possible ways to prove this goal, even though its final result is already guaranteed to be ambiguous. By ignoring all other candidates in that case we can avoid a lot of unnecessary work, fixing the performance regression in typenum found in rust-lang#121848. This is already the behavior in the old solver. This could in theory cause future-compatability issues as considering fewer goals unknowable may end up causing performance regressions/hangs. I am quite confident that this will not be an issue. r? ``@compiler-errors``
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
In case a goal is unknowable, we previously still checked all other possible ways to prove this goal, even though its final result is already guaranteed to be ambiguous. By ignoring all other candidates in that case we can avoid a lot of unnecessary work, fixing the performance regression in typenum found in #121848.
This is already the behavior in the old solver. This could in theory cause future-compatability issues as considering fewer goals unknowable may end up causing performance regressions/hangs. I am quite confident that this will not be an issue.
r? @compiler-errors