Uh oh!
There was an error while loading. Please reload this page.
Customize <FlatMap as Iterator>::fold - #44577
Merged
Merged
Conversation
`FlatMap` can use internal iteration for its `fold`, which shows a performance advantage in the new benchmarks: test iter::bench_flat_map_chain_ref_sum ... bench: 4,354,111 ns/iter (+/- 108,871) test iter::bench_flat_map_chain_sum ... bench: 468,167 ns/iter (+/- 2,274) test iter::bench_flat_map_ref_sum ... bench: 449,616 ns/iter (+/- 6,257) test iter::bench_flat_map_sum ... bench: 348,010 ns/iter (+/- 1,227) ... where the "ref" benches are using `by_ref()` that isn't optimized. So this change shows a decent advantage on its own, but much more when combined with a `chain` iterator that also optimizes `fold`.
alexcrichton
commented
Sep 14, 2017
Member
Thanks! Could you add some tests as well to ensure that the specialization here is correct? (in addition to the benchmarks) |
cuviper
commented
Sep 15, 2017
MemberAuthor
OK, I added a basic test -- did you want something more exhaustive than that? |
alexcrichton
commented
Sep 15, 2017
Member
@bors: r+ Nah looks great! |
bors
commented
Sep 15, 2017
Collaborator
📌 Commit 351f56a has been approved by |
alexcrichton
commented
Sep 16, 2017
Member
@bors: rollup |
alexcrichton added a commit
to alexcrichton/rust
that referenced
this pull request
Sep 16, 2017
Customize `<FlatMap as Iterator>::fold` `FlatMap` can use internal iteration for its `fold`, which shows a performance advantage in the new benchmarks: test iter::bench_flat_map_chain_ref_sum ... bench: 4,354,111 ns/iter (+/- 108,871) test iter::bench_flat_map_chain_sum ... bench: 468,167 ns/iter (+/- 2,274) test iter::bench_flat_map_ref_sum ... bench: 449,616 ns/iter (+/- 6,257) test iter::bench_flat_map_sum ... bench: 348,010 ns/iter (+/- 1,227) ... where the "ref" benches are using `by_ref()` that isn't optimized. So this change shows a decent advantage on its own, but much more when combined with a `chain` iterator that also optimizes `fold`.
frewsxcv added a commit
to frewsxcv/rust
that referenced
this pull request
Sep 16, 2017
Customize `<FlatMap as Iterator>::fold` `FlatMap` can use internal iteration for its `fold`, which shows a performance advantage in the new benchmarks: test iter::bench_flat_map_chain_ref_sum ... bench: 4,354,111 ns/iter (+/- 108,871) test iter::bench_flat_map_chain_sum ... bench: 468,167 ns/iter (+/- 2,274) test iter::bench_flat_map_ref_sum ... bench: 449,616 ns/iter (+/- 6,257) test iter::bench_flat_map_sum ... bench: 348,010 ns/iter (+/- 1,227) ... where the "ref" benches are using `by_ref()` that isn't optimized. So this change shows a decent advantage on its own, but much more when combined with a `chain` iterator that also optimizes `fold`.
alexcrichton added a commit
to alexcrichton/rust
that referenced
this pull request
Sep 17, 2017
Customize `<FlatMap as Iterator>::fold` `FlatMap` can use internal iteration for its `fold`, which shows a performance advantage in the new benchmarks: test iter::bench_flat_map_chain_ref_sum ... bench: 4,354,111 ns/iter (+/- 108,871) test iter::bench_flat_map_chain_sum ... bench: 468,167 ns/iter (+/- 2,274) test iter::bench_flat_map_ref_sum ... bench: 449,616 ns/iter (+/- 6,257) test iter::bench_flat_map_sum ... bench: 348,010 ns/iter (+/- 1,227) ... where the "ref" benches are using `by_ref()` that isn't optimized. So this change shows a decent advantage on its own, but much more when combined with a `chain` iterator that also optimizes `fold`.
bors added a commit
that referenced
this pull request
Sep 17, 2017
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 freeto join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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.
FlatMapcan use internal iteration for itsfold, which shows aperformance advantage in the new benchmarks:
... where the "ref" benches are using
by_ref()that isn't optimized.So this change shows a decent advantage on its own, but much more when
combined with a
chainiterator that also optimizesfold.