[mypyc] feat: further optimize equality check with string literals #19883
+59
−12
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Outdated suggestions cannot be applied.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.
This PR further optimizes string equality checks against literals by getting rid of the PyUnicode_GET_LENGTH call against the literal value, which is not necessary since the value is known at compile-time
I think this optimization will be helpful in cases where the non-literal string DOES match but is actually a subtype of string (actual strings instances that match would be caught by the identity check), or in cases where an exact string does NOT match. But we can also extend this implementation to use c-strings in certain cases where we know at compile-time that the literal value is compact ascii. Actually, maybe I should do that now? Thoughts?