More CRC-32 and Adler-32 updates #353
Merged
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
Owner
ebiggers
commented
Mar 10, 2024
•
ebiggers
commented
- test_checksums: increase number of long inputs tested
- lib/{adler32,crc32}: misc cleanups
- lib/x86/crc32: more optimizations
Various cleanups, including tweaks to make the Adler-32 code more consistent with the CRC-32 code and vice versa. No behavior changes.
- As was recently done in the Adler-32 code, take advantage of the fact that on recent x86 processors, vmovdqu with an aligned pointer is just as fast as vmovdqa. Don't waste time aligning the pointer unless the length is very large, and at the same time, handle all cases of len >= 8*VL using the main loop so that the 4*VL wide loop isn't needed. (Before, aligning the pointer was tied to whether the main loop was used or not, since the main loop used vmovdqa.) - Handle short lengths more efficiently. Instead of falling back to crc32_slice1() for all len < VL, use AVX-512 masking (when available) to handle 4 <= len <= 15, and use 128-bit vector instructions to handle 16 <= len < VL. - Document why the main loop uses a width of 8*VL instead of 4*VL.
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Outdated suggestions cannot be applied.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.