Upgrading lzma_sdk to version 9.20.

third_party/lzma_sdk/C/Bra86.c

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