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Outdated suggestions cannot be applied.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.
By conditionally skipping the 8-bit add-across instruction due to 4-byte characters, we get better performance on Neoverse N1 (ARM CPUs with weak SIMD performance).
The 16-byte addv instruction is one the slowest on N1.
![Screenshot 2024-06-25 at 4 04 06 PM](https://private-user-images.githubusercontent.com/391987/342909337-937e4601-15ee-4b2f-86aa-9bead03036a5.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJnaXRodWIuY29tIiwiYXVkIjoicmF3LmdpdGh1YnVzZXJjb250ZW50LmNvbSIsImtleSI6ImtleTUiLCJleHAiOjE3Mzg5ODQzNjMsIm5iZiI6MTczODk4NDA2MywicGF0aCI6Ii8zOTE5ODcvMzQyOTA5MzM3LTkzN2U0NjAxLTE1ZWUtNGIyZi04NmFhLTliZWFkMDMwMzZhNS5wbmc_WC1BbXotQWxnb3JpdGhtPUFXUzQtSE1BQy1TSEEyNTYmWC1BbXotQ3JlZGVudGlhbD1BS0lBVkNPRFlMU0E1M1BRSzRaQSUyRjIwMjUwMjA4JTJGdXMtZWFzdC0xJTJGczMlMkZhd3M0X3JlcXVlc3QmWC1BbXotRGF0ZT0yMDI1MDIwOFQwMzA3NDNaJlgtQW16LUV4cGlyZXM9MzAwJlgtQW16LVNpZ25hdHVyZT02Nzg2NGRhM2Q2OTM5OGU3YWM3NGE5MGViMzJkNzk2MmQzOTEzZDI5ODE5Yzc1MTNhMjIwN2FkYjFkOWMyYmQyJlgtQW16LVNpZ25lZEhlYWRlcnM9aG9zdCJ9.dlBVemQTmjkw6T0XjhGn3uKmjGjPw45tBDOIfmI8BIA)
It gets much better on N2.
And it is already good on V1: