string: strcat enable use of SIMD
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Authored by getz on Aug 23 2024, 11:02 AM.

Details

Reviewers

fuz
emaste
andrew

Summary

Call into SIMD strlen and stpcpy for an optimized strcat.
Port of D42600 for amd64.

Test Plan

Passes the strcat tests in the test suite

Diff Detail

Repository

rG FreeBSD src repository

Lint

Lint Passed

Unit

No Test Coverage

Build Status

Buildable 59163
Build 56050: arc lint + arc unit

Event Timeline

getz created this revision.Aug 23 2024, 11:02 AM

Herald added a reviewer: andrew. · View Herald TranscriptAug 23 2024, 11:02 AM

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getz requested review of this revision.Aug 23 2024, 11:02 AM

Harbormaster completed remote builds in B59155: Diff 142369.Aug 23 2024, 11:02 AM

revert accidental edit of the makefile

Harbormaster completed remote builds in B59156: Diff 142370.Aug 23 2024, 11:05 AM

getz retitled this revision from lib/libc/aarch64/string: enable use of SIMD to lib/libc/aarch64/string: strcat enable use of SIMD.Aug 23 2024, 11:05 AM

This is probably better done in C code. We don't do any fancy SIMD shenanigans here. The only reason I did it in assembly in D42600 is that the implementation shared a file with an optimised assembly implementation, so it couldn't be done in C.

Code looks ok.

alright, that makes sense. I'll replace it.

strcat in C instead of assembly

Harbormaster completed remote builds in B59163: Diff 142386.Aug 23 2024, 5:38 PM

Could this be made machine independent?

@andrew If we don't have assembly implementations for strlen and stpcpy, it's generally faster to implement this function directly.