Merged
Conversation
…FG (#146456) The add_const() function in flowgraph.c uses a linear search over the consts list to find the index of a constant. After gh-126835 moved constant folding from the AST optimizer to the CFG optimizer, this function is now called N times for N inner tuple elements during fold_tuple_of_constants(), resulting in O(N²) total time. Fix by maintaining an auxiliary _Py_hashtable_t that maps object pointers to their indices in the consts list, providing O(1) lookup. For a file with 100,000 constant 2-tuples: - Before: 10.38s (add_const occupies 83.76% of CPU time) - After: 1.48s
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
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
See Commits and Changes for more details.
Created by
pull[bot] (v2.0.0-alpha.4)
Can you help keep this open source service alive? 💖 Please sponsor : )