40 lines
881 B
C
40 lines
881 B
C
/* 7zCrcT8.c */
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#include "7zCrc.h"
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#define kCrcPoly 0xEDB88320
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#define CRC_NUM_TABLES 8
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UInt32 g_CrcTable[256 * CRC_NUM_TABLES];
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void MY_FAST_CALL CrcGenerateTable()
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{
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UInt32 i;
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for (i = 0; i < 256; i++)
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{
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UInt32 r = i;
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int j;
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for (j = 0; j < 8; j++)
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r = (r >> 1) ^ (kCrcPoly & ~((r & 1) - 1));
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g_CrcTable[i] = r;
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}
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#if CRC_NUM_TABLES > 1
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for (; i < 256 * CRC_NUM_TABLES; i++)
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{
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UInt32 r = g_CrcTable[i - 256];
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g_CrcTable[i] = g_CrcTable[r & 0xFF] ^ (r >> 8);
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}
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#endif
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}
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UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table);
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UInt32 MY_FAST_CALL CrcUpdate(UInt32 v, const void *data, size_t size)
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{
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return CrcUpdateT8(v, data, size, g_CrcTable);
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}
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UInt32 MY_FAST_CALL CrcCalc(const void *data, size_t size)
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{
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return CrcUpdateT8(CRC_INIT_VAL, data, size, g_CrcTable) ^ 0xFFFFFFFF;
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}
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