This patch improves the performance of SSE42 CRC32C algorithm. The current SSE4.2 implementation of CRC32C relies on the native crc32 instruction and processes 8 bytes at a time in a loop. The technique in this paper uses the pclmulqdq instruction and processing 64 bytes at time. The algorithm is based on sse42 version of crc32 computation from Chromium's copy of zlib with modified constants for crc32c computation. See:
https://chromium.googlesource.com/chromium/src/+/refs/heads/main/third_party/zlib/crc32_simd.c Microbenchmarks (generated with google benchmark using a standalone version of the same algorithms): Comparing scalar_crc32c to sse42_crc32c (for various buffer sizes: 64, 128, 256, 512, 1024, 2048 bytes) Benchmark Time CPU Time Old Time New CPU Old CPU New ------------------------------------------------------------------------------------------------------------------------------------ [scalar_crc32c vs. sse42_crc32c]/64 -0.8147 -0.8148 33 6 33 6 [scalar_crc32c vs. sse42_crc32c]/128 -0.8962 -0.8962 88 9 88 9 [scalar_crc32c vs. sse42_crc32c]/256 -0.9200 -0.9200 211 17 211 17 [scalar_crc32c vs. sse42_crc32c]/512 -0.9389 -0.9389 486 30 486 30 [scalar_crc32c vs. sse42_crc32c]/1024 -0.9452 -0.9452 1037 57 1037 57 [scalar_crc32c vs. sse42_crc32c]/2048 -0.9456 -0.9456 2140 116 2140 116 Raghuveer
v1-0001-Add-more-test-coverage-for-crc32c.patch
Description: v1-0001-Add-more-test-coverage-for-crc32c.patch
v1-0002-Improve-CRC32C-performance-on-SSE4.2.patch
Description: v1-0002-Improve-CRC32C-performance-on-SSE4.2.patch
