update libchdr

[pcsx_rearmed.git] / deps / libchdr / deps / lzma-22.01 / src / Bra86.c

/* Bra86.c -- Converter for x86 code (BCJ)\r
2021-02-09 : Igor Pavlov : Public domain */\r
\r
#include "Precomp.h"\r
\r
#include "Bra.h"\r
\r
#define Test86MSByte(b) ((((b) + 1) & 0xFE) == 0)\r
\r
SizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding)\r
{\r
  SizeT pos = 0;\r
  UInt32 mask = *state & 7;\r
  if (size < 5)\r
    return 0;\r
  size -= 4;\r
  ip += 5;\r
\r
  for (;;)\r
  {\r
    Byte *p = data + pos;\r
    const Byte *limit = data + size;\r
    for (; p < limit; p++)\r
      if ((*p & 0xFE) == 0xE8)\r
        break;\r
\r
    {\r
      SizeT d = (SizeT)(p - data) - pos;\r
      pos = (SizeT)(p - data);\r
      if (p >= limit)\r
      {\r
        *state = (d > 2 ? 0 : mask >> (unsigned)d);\r
        return pos;\r
      }\r
      if (d > 2)\r
        mask = 0;\r
      else\r
      {\r
        mask >>= (unsigned)d;\r
        if (mask != 0 && (mask > 4 || mask == 3 || Test86MSByte(p[(size_t)(mask >> 1) + 1])))\r
        {\r
          mask = (mask >> 1) | 4;\r
          pos++;\r
          continue;\r
        }\r
      }\r
    }\r
\r
    if (Test86MSByte(p[4]))\r
    {\r
      UInt32 v = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]);\r
      UInt32 cur = ip + (UInt32)pos;\r
      pos += 5;\r
      if (encoding)\r
        v += cur;\r
      else\r
        v -= cur;\r
      if (mask != 0)\r
      {\r
        unsigned sh = (mask & 6) << 2;\r
        if (Test86MSByte((Byte)(v >> sh)))\r
        {\r
          v ^= (((UInt32)0x100 << sh) - 1);\r
          if (encoding)\r
            v += cur;\r
          else\r
            v -= cur;\r
        }\r
        mask = 0;\r
      }\r
      p[1] = (Byte)v;\r
      p[2] = (Byte)(v >> 8);\r
      p[3] = (Byte)(v >> 16);\r
      p[4] = (Byte)(0 - ((v >> 24) & 1));\r
    }\r
    else\r
    {\r
      mask = (mask >> 1) | 4;\r
      pos++;\r
    }\r
  }\r
}\r