optimize repeat(string, n) for repeating single ASCII chars #22462
Conversation
This file contains 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
|
Cool! Looks good to me. Looks like the Base string benchmarks won't really see this, so probably not worth running Nanosoldier. |
KristofferC
approved these changes
Jun 24, 2017
tkelman
added
the
potential benchmark
DrTodd13
pushed a commit
to IntelLabs/julia
that referenced
this pull request
Jun 26, 2017
ararslan
pushed a commit
that referenced
this pull request
Sep 11, 2017
ararslan
pushed a commit
that referenced
this pull request
Sep 13, 2017
(cherry picked from commit b1c2d73)
vtjnash
pushed a commit
that referenced
this pull request
Sep 14, 2017
(cherry picked from commit b1c2d73)
ararslan
pushed a commit
that referenced
this pull request
Sep 15, 2017
(cherry picked from commit b1c2d73)
KristofferC
removed
the
potential benchmark
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Outdated suggestions cannot be applied.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.
While working on #22461, I noticed that nearly all uses of
repeat(string,n)orstring^nwere for repeating strings consisting of a single ASCII character, most commonly" ". This PR speeds up that case by callingmemset.The speedups vary with length
n. Forn=5I get a 50% speedup, forn=20a 3.5x speedup, and forn=1000I get a 41x speedup.