Fix the size of niche enums with ZST alignment #99959
Merged
Conversation
This file contains hidden or 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
For enums with an aligned ZST variant, like `[T; 0]`, the niche layout was not computing a sufficient size to be consistent with alignment. Now we pad that size up to the alignment, and also make sure to only use the niche variant's ABI when the size and alignment still match.
rustbot
added
the
T-compiler
rust-highfive
added
the
S-waiting-on-review
|
FWIW, #94075 (cc @mikebenfield) also adds the right |
eddyb
approved these changes
Jul 30, 2022
|
@bors r+ rollup=never Thanks! |
bors
added
S-waiting-on-bors
|
☀️ Test successful - checks-actions |
|
Finished benchmarking commit (a231865): comparison url. Instruction countThis benchmark run did not return any relevant results for this metric. Max RSS (memory usage)This benchmark run did not return any relevant results for this metric. CyclesResults
If you disagree with this performance assessment, please file an issue in rust-lang/rustc-perf. @rustbot label: -perf-regression Footnotes |
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Outdated suggestions cannot be applied.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.
For enums with an aligned ZST variant, like
[T; 0], the niche layoutwas not computing a sufficient size to be consistent with alignment. Now
we pad that size up to the alignment, and also make sure to only use the
niche variant's ABI when the size and alignment still match.
Fixes #99836
r? @eddyb