FreeBSD/Linux Kernel Cross Reference
sys/contrib/xz-embedded/linux/lib/xz/xz_crc64.c

     /*
      * CRC64 using the polynomial from ECMA-182
      *
      * This file is similar to xz_crc32.c. See the comments there.
      *
      * Authors: Lasse Collin <lasse.collin@tukaani.org>
      *          Igor Pavlov <https://7-zip.org/>
      *
      * This file has been put into the public domain.
     * You can do whatever you want with this file.
     */
    
    #include "xz_private.h"
    
    #ifndef STATIC_RW_DATA
    #       define STATIC_RW_DATA static
    #endif
    
    STATIC_RW_DATA uint64_t xz_crc64_table[256];
    
    XZ_EXTERN void xz_crc64_init(void)
    {
            /*
             * The ULL suffix is needed for -std=gnu89 compatibility
             * on 32-bit platforms.
             */
            const uint64_t poly = 0xC96C5795D7870F42ULL;
    
            uint32_t i;
            uint32_t j;
            uint64_t r;
    
            for (i = 0; i < 256; ++i) {
                    r = i;
                    for (j = 0; j < 8; ++j)
                            r = (r >> 1) ^ (poly & ~((r & 1) - 1));
    
                    xz_crc64_table[i] = r;
            }
    
            return;
    }
    
    XZ_EXTERN uint64_t xz_crc64(const uint8_t *buf, size_t size, uint64_t crc)
    {
            crc = ~crc;
    
            while (size != 0) {
                    crc = xz_crc64_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
                    --size;
            }
    
            return ~crc;
    }

Cache object: 0f985193b1d5c9c4f9bd70aa383208b5