Sync BaseTools Trunk (version r2518) to EDKII main trunk.

[mirror_edk2.git] / BaseTools / Source / C / LzmaCompress / Sdk / C / Bra86.c

/* Bra86.c -- Converter for x86 code (BCJ)\r
2008-10-04 : Igor Pavlov : Public domain */\r
\r
#include "Bra.h"\r
\r
#define Test86MSByte(b) ((b) == 0 || (b) == 0xFF)\r
\r
const Byte kMaskToAllowedStatus[8] = {1, 1, 1, 0, 1, 0, 0, 0};\r
const Byte kMaskToBitNumber[8] = {0, 1, 2, 2, 3, 3, 3, 3};\r
\r
SizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding)\r
{\r
  SizeT bufferPos = 0, prevPosT;\r
  UInt32 prevMask = *state & 0x7;\r
  if (size < 5)\r
    return 0;\r
  ip += 5;\r
  prevPosT = (SizeT)0 - 1;\r
\r
  for (;;)\r
  {\r
    Byte *p = data + bufferPos;\r
    Byte *limit = data + size - 4;\r
    for (; p < limit; p++)\r
      if ((*p & 0xFE) == 0xE8)\r
        break;\r
    bufferPos = (SizeT)(p - data);\r
    if (p >= limit)\r
      break;\r
    prevPosT = bufferPos - prevPosT;\r
    if (prevPosT > 3)\r
      prevMask = 0;\r
    else\r
    {\r
      prevMask = (prevMask << ((int)prevPosT - 1)) & 0x7;\r
      if (prevMask != 0)\r
      {\r
        Byte b = p[4 - kMaskToBitNumber[prevMask]];\r
        if (!kMaskToAllowedStatus[prevMask] || Test86MSByte(b))\r
        {\r
          prevPosT = bufferPos;\r
          prevMask = ((prevMask << 1) & 0x7) | 1;\r
          bufferPos++;\r
          continue;\r
        }\r
      }\r
    }\r
    prevPosT = bufferPos;\r
\r
    if (Test86MSByte(p[4]))\r
    {\r
      UInt32 src = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]);\r
      UInt32 dest;\r
      for (;;)\r
      {\r
        Byte b;\r
        int index;\r
        if (encoding)\r
          dest = (ip + (UInt32)bufferPos) + src;\r
        else\r
          dest = src - (ip + (UInt32)bufferPos);\r
        if (prevMask == 0)\r
          break;\r
        index = kMaskToBitNumber[prevMask] * 8;\r
        b = (Byte)(dest >> (24 - index));\r
        if (!Test86MSByte(b))\r
          break;\r
        src = dest ^ ((1 << (32 - index)) - 1);\r
      }\r
      p[4] = (Byte)(~(((dest >> 24) & 1) - 1));\r
      p[3] = (Byte)(dest >> 16);\r
      p[2] = (Byte)(dest >> 8);\r
      p[1] = (Byte)dest;\r
      bufferPos += 5;\r
    }\r
    else\r
    {\r
      prevMask = ((prevMask << 1) & 0x7) | 1;\r
      bufferPos++;\r
    }\r
  }\r
  prevPosT = bufferPos - prevPosT;\r
  *state = ((prevPosT > 3) ? 0 : ((prevMask << ((int)prevPosT - 1)) & 0x7));\r
  return bufferPos;\r
}\r