rlm@1: /* 7zCrc.c -- CRC32 calculation
rlm@1: 2008-08-05
rlm@1: Igor Pavlov
rlm@1: Public domain */
rlm@1: 
rlm@1: #include "7zCrc.h"
rlm@1: 
rlm@1: #define kCrcPoly 0xEDB88320
rlm@1: UInt32 g_CrcTable[256];
rlm@1: 
rlm@1: void MY_FAST_CALL CrcGenerateTable(void)
rlm@1: {
rlm@1:   UInt32 i;
rlm@1:   for (i = 0; i < 256; i++)
rlm@1:   {
rlm@1:     UInt32 r = i;
rlm@1:     int j;
rlm@1:     for (j = 0; j < 8; j++)
rlm@1:       r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
rlm@1:     g_CrcTable[i] = r;
rlm@1:   }
rlm@1: }
rlm@1: 
rlm@1: UInt32 MY_FAST_CALL CrcUpdate(UInt32 v, const void *data, size_t size)
rlm@1: {
rlm@1:   const Byte *p = (const Byte *)data;
rlm@1:   for (; size > 0 ; size--, p++)
rlm@1:     v = CRC_UPDATE_BYTE(v, *p);
rlm@1:   return v;
rlm@1: }
rlm@1: 
rlm@1: UInt32 MY_FAST_CALL CrcCalc(const void *data, size_t size)
rlm@1: {
rlm@1:   return CrcUpdate(CRC_INIT_VAL, data, size) ^ 0xFFFFFFFF;
rlm@1: }