Mercurial > vba-linux
view src/win32/7zip/7z/C/Bra86.c @ 4:5f6f2134e8ce
apu appears to not be used
author | Robert McIntyre <rlm@mit.edu> |
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date | Sat, 03 Mar 2012 10:35:58 -0600 |
parents | f9f4f1b99eed |
children |
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1 /* Bra86.c -- Converter for x86 code (BCJ)2 2008-10-04 : Igor Pavlov : Public domain */4 #include "Bra.h"6 #define Test86MSByte(b) ((b) == 0 || (b) == 0xFF)8 const Byte kMaskToAllowedStatus[8] = {1, 1, 1, 0, 1, 0, 0, 0};9 const Byte kMaskToBitNumber[8] = {0, 1, 2, 2, 3, 3, 3, 3};11 SizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding)12 {13 SizeT bufferPos = 0, prevPosT;14 UInt32 prevMask = *state & 0x7;15 if (size < 5)16 return 0;17 ip += 5;18 prevPosT = (SizeT)0 - 1;20 for (;;)21 {22 Byte *p = data + bufferPos;23 Byte *limit = data + size - 4;24 for (; p < limit; p++)25 if ((*p & 0xFE) == 0xE8)26 break;27 bufferPos = (SizeT)(p - data);28 if (p >= limit)29 break;30 prevPosT = bufferPos - prevPosT;31 if (prevPosT > 3)32 prevMask = 0;33 else34 {35 prevMask = (prevMask << ((int)prevPosT - 1)) & 0x7;36 if (prevMask != 0)37 {38 Byte b = p[4 - kMaskToBitNumber[prevMask]];39 if (!kMaskToAllowedStatus[prevMask] || Test86MSByte(b))40 {41 prevPosT = bufferPos;42 prevMask = ((prevMask << 1) & 0x7) | 1;43 bufferPos++;44 continue;45 }46 }47 }48 prevPosT = bufferPos;50 if (Test86MSByte(p[4]))51 {52 UInt32 src = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]);53 UInt32 dest;54 for (;;)55 {56 Byte b;57 int index;58 if (encoding)59 dest = (ip + (UInt32)bufferPos) + src;60 else61 dest = src - (ip + (UInt32)bufferPos);62 if (prevMask == 0)63 break;64 index = kMaskToBitNumber[prevMask] * 8;65 b = (Byte)((dest >> (24 - index)) & 0xFF);66 if (!Test86MSByte(b))67 break;68 src = dest ^ ((1 << (32 - index)) - 1);69 }70 p[4] = (Byte)((~(((dest >> 24) & 1) - 1)) & 0xFF);71 p[3] = (Byte)((dest >> 16) & 0xFF);72 p[2] = (Byte)((dest >> 8) & 0xFF);73 p[1] = (Byte)(dest & 0xFF);74 bufferPos += 5;75 }76 else77 {78 prevMask = ((prevMask << 1) & 0x7) | 1;79 bufferPos++;80 }81 }82 prevPosT = bufferPos - prevPosT;83 *state = ((prevPosT > 3) ? 0 : ((prevMask << ((int)prevPosT - 1)) & 0x7));84 return bufferPos;85 }