Computing Adler32 Checksums at 41 GB/s

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  • fpng

    Super fast C++ .PNG writer/reader

    This was actually considered, and other libraries do ignore checksums, or at least have options to:

  • oss-nvjpg

    Hardware-accelerated JPEG decoding on the Nvidia Tegra X1

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  • wuffs

    Wrangling Untrusted File Formats Safely

    Like the fpng implementation, it's SSE (128-bit registers), but the inner loop eats 32 bytes at a time, not 16.

    "Wuffs’ Adler-32 implementation is around 6.4x faster (11.3GB/s vs 1.76GB/s) than the one from zlib-the-library", which IIUC is roughly comparable to the article's defer32.

  • libdeflate

    Heavily optimized library for DEFLATE/zlib/gzip compression and decompression

    Note that libdeflate has used essentially the same method since 2016 (, though I recently switched it to use a slightly different method ( that performs more consistently across different families of x86 CPUs.

  • zlib-ng

    zlib replacement with optimizations for "next generation" systems.

    zlib-ng also has adler32 implementations optimized for various architectures:

    Might be interesting to benchmark their implementation too to see how it compares.

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