fix(skills): misleading DCE advice in setup-harness#350
Open
SuperMuel wants to merge 2 commits into
Open
Conversation
`benchmark.pedantic` is not a dead-code-elimination tool; it controls the measurement loop. CPython doesn't perform the kind of DCE that `black_box` guards against in compiled languages, so pure-Python benchmarks don't need an equivalent. List the actual primitives for the languages that do (C++: DoNotOptimize, JMH: Blackhole.consume).
Merging this PR will not alter performance
|
Caught by the trailing-whitespace pre-commit hook on PR #350.
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 join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
The skill told users to use
benchmark.pedantic()in Python to prevent dead code elimination, likeblack_box()in Rust. Two problems with that.benchmark.pedanticdoes not prevent dead code elimination. It just lets you set rounds, iterations, and a setup function for the benchmark.CPython does not delete unused function calls. It can't know if a function has side effects, so it always runs it. Pure-Python benchmarks do not need a
black_box.The new wording only mentions compiled languages and uses the right name for each one.