diff options
Diffstat (limited to 'C/XzCrc64Opt.c')
-rw-r--r-- | C/XzCrc64Opt.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/C/XzCrc64Opt.c b/C/XzCrc64Opt.c new file mode 100644 index 00000000..dccae1c1 --- /dev/null +++ b/C/XzCrc64Opt.c @@ -0,0 +1,69 @@ +/* XzCrc64Opt.c -- CRC64 calculation +2011-06-28 : Igor Pavlov : Public domain */ + +#include "Precomp.h" + +#include "CpuArch.h" + +#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8)) + +#ifndef MY_CPU_BE + +UInt64 MY_FAST_CALL XzCrc64UpdateT4(UInt64 v, const void *data, size_t size, const UInt64 *table) +{ + const Byte *p = (const Byte *)data; + for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++) + v = CRC_UPDATE_BYTE_2(v, *p); + for (; size >= 4; size -= 4, p += 4) + { + UInt32 d = (UInt32)v ^ *(const UInt32 *)p; + v = (v >> 32) ^ + table[0x300 + ((d ) & 0xFF)] ^ + table[0x200 + ((d >> 8) & 0xFF)] ^ + table[0x100 + ((d >> 16) & 0xFF)] ^ + table[0x000 + ((d >> 24))]; + } + for (; size > 0; size--, p++) + v = CRC_UPDATE_BYTE_2(v, *p); + return v; +} + +#endif + + +#ifndef MY_CPU_LE + +#define CRC_UINT64_SWAP(v) \ + ((v >> 56) | \ + ((v >> 40) & ((UInt64)0xFF << 8)) | \ + ((v >> 24) & ((UInt64)0xFF << 16)) | \ + ((v >> 8) & ((UInt64)0xFF << 24)) | \ + ((v << 8) & ((UInt64)0xFF << 32)) | \ + ((v << 24) & ((UInt64)0xFF << 40)) | \ + ((v << 40) & ((UInt64)0xFF << 48)) | \ + (v << 56)) + +UInt64 MY_FAST_CALL XzCrc64UpdateT1_BeT4(UInt64 v, const void *data, size_t size, const UInt64 *table) +{ + const Byte *p = (const Byte *)data; + for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++) + v = CRC_UPDATE_BYTE_2(v, *p); + v = CRC_UINT64_SWAP(v); + table += 0x100; + for (; size >= 4; size -= 4, p += 4) + { + UInt32 d = (UInt32)(v >> 32) ^ *(const UInt32 *)p; + v = (v << 32) ^ + table[0x000 + ((d ) & 0xFF)] ^ + table[0x100 + ((d >> 8) & 0xFF)] ^ + table[0x200 + ((d >> 16) & 0xFF)] ^ + table[0x300 + ((d >> 24))]; + } + table -= 0x100; + v = CRC_UINT64_SWAP(v); + for (; size > 0; size--, p++) + v = CRC_UPDATE_BYTE_2(v, *p); + return v; +} + +#endif |