Do not use Stateful for cmp of AbstractString #47125
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
PR JuliaLang#45924 fixed length of Stateful, but this change requires Stateful to call length on its wrapped iterator on instantiation. The current implementation of cmp(::AbstractString, ::AbstractString) wraps the strings in Stateful to efficiently check if one string is longer than the other without needing an O(N) call to length. However, with JuliaLang#45924 this length call is done anyway, which led to a performance regression. In this PR, the cmp method is changed so it no longer relies on Stateful to do the same thing. Fix JuliaLang#46719
vtjnash
approved these changes
Oct 11, 2022
|
As far as I can tell, these various errors are unrelated |
|
@nanosoldier |
|
Your benchmark job has completed - possible performance regressions were detected. A full report can be found here. |
aviatesk
approved these changes
Oct 12, 2022
|
@nanosoldier |
|
Your benchmark job has completed - no performance regressions were detected. A full report can be found here. |
|
Doubling the old performance is also quite good |
aviatesk
approved these changes
Oct 12, 2022
DilumAluthge
removed
the
merge me
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Outdated suggestions cannot be applied.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.
PR #45924 fixed length of
Stateful, but this change requiresStatefulto calllengthon its wrapped iterator on instantiation.The current implementation of
cmp(::AbstractString, ::AbstractString)wraps thestrings in
Statefulto efficiently check if one string is longer than the otherwithout needing an O(N) call to
length.However, with #45924 this length call is done anyway, which led to a performance
regression.
In this PR, the
cmpmethod is changed so it no longer relies onStatefulto dothe same thing.
Fix #46719
Note to reviewers: I agree that it's not ideal that
Statefulnow callslength on instantiation. But I can't think of a way to ensure correct behaviour ofStatefulwithout doing that. Furthermore, sinceStatefulnow (after #45924) caches thelengthcall,Statefulis only slower in the case wherelengthis slow to compute and it's not called, as is the case for this particularcmpmethod.