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