mirror of https://github.com/bsnes-emu/bsnes.git
70 lines
1.6 KiB
C++
Executable File
70 lines
1.6 KiB
C++
Executable File
#include "rar.hpp"
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uint CRCTab[256];
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void InitCRC()
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{
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for (int I=0;I<256;I++)
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{
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uint C=I;
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for (int J=0;J<8;J++)
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C=(C & 1) ? (C>>1)^0xEDB88320L : (C>>1);
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CRCTab[I]=C;
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}
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}
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uint CRC(uint StartCRC,const void *Addr,size_t Size)
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{
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// Always initialized ahead of time, and this func call makes it a non-leaf func.
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if (false)
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if (CRCTab[1]==0)
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InitCRC();
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byte *Data=(byte *)Addr;
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#if defined(LITTLE_ENDIAN) && defined(PRESENT_INT32) && defined(ALLOW_NOT_ALIGNED_INT)
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#ifdef _MSC_VER
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// avoid a warning about 'Data' pointer truncation in 64 bit mode
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#pragma warning( disable : 4311 )
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#endif
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while (Size>0 && ((long)Data & 7))
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{
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StartCRC=CRCTab[(byte)(StartCRC^Data[0])]^(StartCRC>>8);
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Size--;
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Data++;
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}
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while (Size>=8)
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{
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StartCRC^=*(uint32 *)Data;
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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StartCRC^=*(uint32 *)(Data+4);
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
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Data+=8;
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Size-=8;
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}
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#endif
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for (size_t I=0;I<Size;I++)
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StartCRC=CRCTab[(byte)(StartCRC^Data[I])]^(StartCRC>>8);
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return(StartCRC);
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}
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#ifndef SFX_MODULE
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ushort OldCRC(ushort StartCRC,const void *Addr,size_t Size)
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{
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byte *Data=(byte *)Addr;
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for (size_t I=0;I<Size;I++)
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{
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StartCRC=(StartCRC+Data[I])&0xffff;
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StartCRC=((StartCRC<<1)|(StartCRC>>15))&0xffff;
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}
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return(StartCRC);
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}
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#endif
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