1baa3858d3f5d128a5c8466b700098109edcad5f2repo sync/* Bra86.c -- Converter for x86 code (BCJ) 2baa3858d3f5d128a5c8466b700098109edcad5f2repo sync2008-10-04 : Igor Pavlov : Public domain */ 3baa3858d3f5d128a5c8466b700098109edcad5f2repo sync 4baa3858d3f5d128a5c8466b700098109edcad5f2repo sync#include "Bra.h" 5baa3858d3f5d128a5c8466b700098109edcad5f2repo sync 6baa3858d3f5d128a5c8466b700098109edcad5f2repo sync#define Test86MSByte(b) ((b) == 0 || (b) == 0xFF) 7baa3858d3f5d128a5c8466b700098109edcad5f2repo sync 8baa3858d3f5d128a5c8466b700098109edcad5f2repo syncconst Byte kMaskToAllowedStatus[8] = {1, 1, 1, 0, 1, 0, 0, 0}; 9baa3858d3f5d128a5c8466b700098109edcad5f2repo syncconst Byte kMaskToBitNumber[8] = {0, 1, 2, 2, 3, 3, 3, 3}; 10baa3858d3f5d128a5c8466b700098109edcad5f2repo sync 11baa3858d3f5d128a5c8466b700098109edcad5f2repo syncSizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding) 12baa3858d3f5d128a5c8466b700098109edcad5f2repo sync{ 13baa3858d3f5d128a5c8466b700098109edcad5f2repo sync SizeT bufferPos = 0, prevPosT; 14baa3858d3f5d128a5c8466b700098109edcad5f2repo sync UInt32 prevMask = *state & 0x7; 15baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (size < 5) 16baa3858d3f5d128a5c8466b700098109edcad5f2repo sync return 0; 17baa3858d3f5d128a5c8466b700098109edcad5f2repo sync ip += 5; 18baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevPosT = (SizeT)0 - 1; 19baa3858d3f5d128a5c8466b700098109edcad5f2repo sync 20baa3858d3f5d128a5c8466b700098109edcad5f2repo sync for (;;) 21baa3858d3f5d128a5c8466b700098109edcad5f2repo sync { 22baa3858d3f5d128a5c8466b700098109edcad5f2repo sync Byte *p = data + bufferPos; 23baa3858d3f5d128a5c8466b700098109edcad5f2repo sync Byte *limit = data + size - 4; 24baa3858d3f5d128a5c8466b700098109edcad5f2repo sync for (; p < limit; p++) 25baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if ((*p & 0xFE) == 0xE8) 26baa3858d3f5d128a5c8466b700098109edcad5f2repo sync break; 27baa3858d3f5d128a5c8466b700098109edcad5f2repo sync bufferPos = (SizeT)(p - data); 28baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (p >= limit) 29baa3858d3f5d128a5c8466b700098109edcad5f2repo sync break; 30baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevPosT = bufferPos - prevPosT; 31baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (prevPosT > 3) 32baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevMask = 0; 33baa3858d3f5d128a5c8466b700098109edcad5f2repo sync else 34baa3858d3f5d128a5c8466b700098109edcad5f2repo sync { 35baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevMask = (prevMask << ((int)prevPosT - 1)) & 0x7; 36baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (prevMask != 0) 37baa3858d3f5d128a5c8466b700098109edcad5f2repo sync { 38baa3858d3f5d128a5c8466b700098109edcad5f2repo sync Byte b = p[4 - kMaskToBitNumber[prevMask]]; 39baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (!kMaskToAllowedStatus[prevMask] || Test86MSByte(b)) 40baa3858d3f5d128a5c8466b700098109edcad5f2repo sync { 41baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevPosT = bufferPos; 42baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevMask = ((prevMask << 1) & 0x7) | 1; 43baa3858d3f5d128a5c8466b700098109edcad5f2repo sync bufferPos++; 44baa3858d3f5d128a5c8466b700098109edcad5f2repo sync continue; 45baa3858d3f5d128a5c8466b700098109edcad5f2repo sync } 46baa3858d3f5d128a5c8466b700098109edcad5f2repo sync } 47baa3858d3f5d128a5c8466b700098109edcad5f2repo sync } 48baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevPosT = bufferPos; 49baa3858d3f5d128a5c8466b700098109edcad5f2repo sync 50baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (Test86MSByte(p[4])) 51baa3858d3f5d128a5c8466b700098109edcad5f2repo sync { 52baa3858d3f5d128a5c8466b700098109edcad5f2repo sync UInt32 src = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]); 53baa3858d3f5d128a5c8466b700098109edcad5f2repo sync UInt32 dest; 54baa3858d3f5d128a5c8466b700098109edcad5f2repo sync for (;;) 55baa3858d3f5d128a5c8466b700098109edcad5f2repo sync { 56baa3858d3f5d128a5c8466b700098109edcad5f2repo sync Byte b; 57baa3858d3f5d128a5c8466b700098109edcad5f2repo sync int index; 58baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (encoding) 59baa3858d3f5d128a5c8466b700098109edcad5f2repo sync dest = (ip + (UInt32)bufferPos) + src; 60baa3858d3f5d128a5c8466b700098109edcad5f2repo sync else 61baa3858d3f5d128a5c8466b700098109edcad5f2repo sync dest = src - (ip + (UInt32)bufferPos); 62baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (prevMask == 0) 63baa3858d3f5d128a5c8466b700098109edcad5f2repo sync break; 64baa3858d3f5d128a5c8466b700098109edcad5f2repo sync index = kMaskToBitNumber[prevMask] * 8; 65baa3858d3f5d128a5c8466b700098109edcad5f2repo sync b = (Byte)(dest >> (24 - index)); 66baa3858d3f5d128a5c8466b700098109edcad5f2repo sync if (!Test86MSByte(b)) 67baa3858d3f5d128a5c8466b700098109edcad5f2repo sync break; 68baa3858d3f5d128a5c8466b700098109edcad5f2repo sync src = dest ^ ((1 << (32 - index)) - 1); 69baa3858d3f5d128a5c8466b700098109edcad5f2repo sync } 70baa3858d3f5d128a5c8466b700098109edcad5f2repo sync p[4] = (Byte)(~(((dest >> 24) & 1) - 1)); 71baa3858d3f5d128a5c8466b700098109edcad5f2repo sync p[3] = (Byte)(dest >> 16); 72baa3858d3f5d128a5c8466b700098109edcad5f2repo sync p[2] = (Byte)(dest >> 8); 73baa3858d3f5d128a5c8466b700098109edcad5f2repo sync p[1] = (Byte)dest; 74baa3858d3f5d128a5c8466b700098109edcad5f2repo sync bufferPos += 5; 75baa3858d3f5d128a5c8466b700098109edcad5f2repo sync } 76baa3858d3f5d128a5c8466b700098109edcad5f2repo sync else 77baa3858d3f5d128a5c8466b700098109edcad5f2repo sync { 78baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevMask = ((prevMask << 1) & 0x7) | 1; 79baa3858d3f5d128a5c8466b700098109edcad5f2repo sync bufferPos++; 80baa3858d3f5d128a5c8466b700098109edcad5f2repo sync } 81baa3858d3f5d128a5c8466b700098109edcad5f2repo sync } 82baa3858d3f5d128a5c8466b700098109edcad5f2repo sync prevPosT = bufferPos - prevPosT; 83baa3858d3f5d128a5c8466b700098109edcad5f2repo sync *state = ((prevPosT > 3) ? 0 : ((prevMask << ((int)prevPosT - 1)) & 0x7)); 84baa3858d3f5d128a5c8466b700098109edcad5f2repo sync return bufferPos; 85baa3858d3f5d128a5c8466b700098109edcad5f2repo sync} 86