uucore: num_format: Optimize format_float_shortest
#8444
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
Both format_float_scientific and format_float_shortest carry the same code, moving it to a single function will make it possible to optimize both.
with_prec is actually really expensive, so it's much better to
just call it once, and handle the rounding corner case manually.
Saves about ~20% performance on:
```
{seq} -f "%g" 0 1e-9 1e-3
```
We already know the String length ahead of time, and we can
avoid using `format`.
Saves about ~30% performance on:
```
{seq} -f "%g" 0 1e-9 1e-3
```
|
GNU testsuite comparison: |
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Outdated suggestions cannot be applied.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.
Optimizing for the
%gprintf format. I don't particularly care about the usecase below, but I'm thinking of movingodto the common formatter, where those optimizations would be welcome.We're still 20% away from coreutils, but this picks some of the low hanging fruits.
uucore: num_format: Optimize format_float_shortest
We already know the String length ahead of time, and we can
avoid using
format.Saves about ~30% performance on:
uucore: num_format: Reduce calls to with_prec
with_prec is actually really expensive, so it's much better to
just call it once, and handle the rounding corner case manually.
Saves about ~20% performance on:
uucore: num_format: Move common scientific formatting code to a function
Both format_float_scientific and format_float_shortest carry the
same code, moving it to a single function will make it possible
to optimize both.