CRC32 28 ext/standard/crc32.h #define CRC32(crc, ch) (crc = (crc >> 8) ^ crc32tab[(crc ^ (ch)) & 0xff]) CRC32 54 ext/zip/lib/zip_source_pkware.c #define CRC32(c, b) (crc[((c) ^ (b)) & 0xff] ^ ((c) >> 8))