diff options
Diffstat (limited to 'src/libs/7zip/unix/C/7zCrcT8.c')
-rw-r--r-- | src/libs/7zip/unix/C/7zCrcT8.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/libs/7zip/unix/C/7zCrcT8.c b/src/libs/7zip/unix/C/7zCrcT8.c new file mode 100644 index 000000000..cd80e262b --- /dev/null +++ b/src/libs/7zip/unix/C/7zCrcT8.c @@ -0,0 +1,43 @@ +/* 7zCrcT8.c -- CRC32 calculation with 8 tables +2008-03-19 +Igor Pavlov +Public domain */ + +#include "7zCrc.h" + +#define kCrcPoly 0xEDB88320 +#define CRC_NUM_TABLES 8 + +UInt32 g_CrcTable[256 * CRC_NUM_TABLES]; + +void MY_FAST_CALL CrcGenerateTable() +{ + UInt32 i; + for (i = 0; i < 256; i++) + { + UInt32 r = i; + int j; + for (j = 0; j < 8; j++) + r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1)); + g_CrcTable[i] = r; + } + #if CRC_NUM_TABLES > 1 + for (; i < 256 * CRC_NUM_TABLES; i++) + { + UInt32 r = g_CrcTable[i - 256]; + g_CrcTable[i] = g_CrcTable[r & 0xFF] ^ (r >> 8); + } + #endif +} + +UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table); + +UInt32 MY_FAST_CALL CrcUpdate(UInt32 v, const void *data, size_t size) +{ + return CrcUpdateT8(v, data, size, g_CrcTable); +} + +UInt32 MY_FAST_CALL CrcCalc(const void *data, size_t size) +{ + return CrcUpdateT8(CRC_INIT_VAL, data, size, g_CrcTable) ^ 0xFFFFFFFF; +} |