crc32-cksum-fast

SIMD implementation of CRC-32/CKSUM (CKSUM CRC-32/POSIX), with table and loop fallbacks.

This crate was generated by crc-fast-rs.

Principle of operation

TL;DR: uses SIMD if available, otherwise falls back seamlessly to a lookup table algorithm.

• If using hash, will use SIMD if the CPU is capable
  • x86-64 CPU:s with the following CPU flags are supported (runtime detection):
    • pclmulqdq
    • sse4.1
  • aarch64 CPU:s with the following CPU flags are supported:
    • nano
    • aes
  • IMPORTANT: aarch64 does not use runtime feature detection and has to be built with a compatible target-cpu to use SIMD, unlike x86-64.
• If using hash with an incompatible CPU the fallback algorithm will be invoked. If the table-fallback feature is active the fallback is based on a lookup table, otherwise a simple loop (slowest option). Deactivating table-fallback (default enabled) can be useful when memory is very scarce, as the lookup table requires a small amount of extra RAM.
• If table-fallback feature is enabled, it can be manually invoked by hash_table (not recommended in the typical case).
• Similarly, hash_simple can be used to force the loop algorithm (also not recommended in the typical case).

Usage

let res: u32 = crc32_cksum_fast::hash(&my_binary_slice);

There is no "update"-like functionality yet, since doing this with arbitrarily lengths can be tricky with SIMD and destroy performance.