#popcount #hamming #avx2


Computes Hamming distance and weight -- if available, uses a highly optimized avx2 implementation

6 releases

0.2.21 Apr 20, 2022
0.2.2 Apr 17, 2022
0.1.1 Apr 16, 2022

#13 in #hamming

MIT license

417 lines


Computes hamming distance and weight, possibly with avx/avx2 instructions for x86 processors
avx2 optimized version is used when inputs have same memory alignment
otherwise, functions will fallback to slower versions


Muła, Wojciech, Nathan Kurz, and Daniel Lemire. "Faster population counts using AVX2 instructions." The Computer Journal 61.1 (2018): 111-120.



We ran benchmarks with cargo bench on a laptop with a Intel core i7-8750H @2.2Ghz with 16Gb of RAM
We compare the avx2 version (with inputs aligned to 256 bytes) against hamming and strsim reference crates
We notice a speedup of ~4 against hamming and of ~100 against strsim

hamming_rs vs hamming hamming_rs vs strsim

No runtime deps