faster rand(TaskLocalRNG(), 1:n) by outlining throw
#58306
Merged
Conversation
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
In #58089, this method took a small performance hit in some contexts. It turns out that by outlining unlikely branch which throw on empty ranges, his hit can be recovered. In #50509 (comment), a graph of the performance improvement of the "speed-up randperm by using our current rand(1:n)" was posted, but I realized it was only true when calls to `rand(1:n)` were prefixed by `@inline`; without `@inline` it was overall slower for `TaskLocalRNG()` for very big arrays (but still faster otherwise). An alternative to these `@inline` annotation is to outline `throw` like here, for equivalent benefits as `@inline` in that `randperm` PR. Assuming that PR is merged, this PR improves roughly performance by 2x for `TaskLocalRNG()` (no change for other RNGs).
rfourquet
added
performance
Zentrik
reviewed
May 5, 2025
charleskawczynski
pushed a commit
to charleskawczynski/julia
that referenced
this pull request
May 12, 2025
) In JuliaLang#58089, this method took a small performance hit in some contexts. It turns out that by outlining the unlikely branch which throws on empty ranges, this hit can be recovered. In JuliaLang#50509 (comment), a graph of the performance improvement of the "speed-up randperm by using our current rand(1:n)" was posted, but I realized it was only true when calls to `rand(1:n)` were prefixed by `@inline`; without `@inline` it was overall slower for `TaskLocalRNG()` for very big arrays (but still faster otherwise). An alternative to these `@inline` annotation is to outline `throw` like here, for equivalent benefits as `@inline` in that `randperm` PR. Assuming that PR is merged, this PR improves roughly performance by 2x for `TaskLocalRNG()` (no change for other RNGs):  While at it, I outlined a bunch of other unliky throwing branches. After that, JuliaLang#50509 can probably be merged, finally!
charleskawczynski
pushed a commit
to charleskawczynski/julia
that referenced
this pull request
May 12, 2025
) In JuliaLang#58089, this method took a small performance hit in some contexts. It turns out that by outlining the unlikely branch which throws on empty ranges, this hit can be recovered. In JuliaLang#50509 (comment), a graph of the performance improvement of the "speed-up randperm by using our current rand(1:n)" was posted, but I realized it was only true when calls to `rand(1:n)` were prefixed by `@inline`; without `@inline` it was overall slower for `TaskLocalRNG()` for very big arrays (but still faster otherwise). An alternative to these `@inline` annotation is to outline `throw` like here, for equivalent benefits as `@inline` in that `randperm` PR. Assuming that PR is merged, this PR improves roughly performance by 2x for `TaskLocalRNG()` (no change for other RNGs):  While at it, I outlined a bunch of other unliky throwing branches. After that, JuliaLang#50509 can probably be merged, finally!
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.
In #58089, this method took a small performance hit in some contexts. It turns out that by outlining the unlikely branch which throws on empty ranges, this hit can be recovered.
In #50509 (comment), a graph of the performance improvement of the "speed-up randperm by using our current rand(1:n)" was posted, but I realized it was only true when calls to
rand(1:n)were prefixed by@inline; without@inlineit was overall slower forTaskLocalRNG()for very big arrays (but still faster otherwise).An alternative to these
@inlineannotation is to outlinethrowlike here, for equivalent benefits as@inlinein thatrandpermPR.Assuming that PR is merged, this PR improves roughly performance by 2x for
TaskLocalRNG()(no change for other RNGs):While at it, I outlined a bunch of other unliky throwing branches.
After that, #50509 can probably be merged, finally!