misc/libphysfs/lzma/C/Compress/Branch/BranchX86_2.c
changeset 12213 bb5522e88ab2
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libphysfs/lzma/C/Compress/Branch/BranchX86_2.c	Mon Apr 10 12:06:43 2017 -0400
@@ -0,0 +1,135 @@
+// BranchX86_2.c
+
+#include "BranchX86_2.h"
+
+#include "../../Alloc.h"
+
+#ifdef _LZMA_PROB32
+#define CProb UInt32
+#else
+#define CProb UInt16
+#endif
+
+#define IsJcc(b0, b1) ((b0) == 0x0F && ((b1) & 0xF0) == 0x80)
+#define IsJ(b0, b1) ((b1 & 0xFE) == 0xE8 || IsJcc(b0, b1))
+
+#define kNumTopBits 24
+#define kTopValue ((UInt32)1 << kNumTopBits)
+
+#define kNumBitModelTotalBits 11
+#define kBitModelTotal (1 << kNumBitModelTotalBits)
+#define kNumMoveBits 5
+
+#define RC_READ_BYTE (*Buffer++)
+
+#define RC_INIT2 Code = 0; Range = 0xFFFFFFFF; \
+  { int i; for(i = 0; i < 5; i++) { RC_TEST; Code = (Code << 8) | RC_READ_BYTE; }}
+
+#define RC_TEST { if (Buffer == BufferLim) return BCJ2_RESULT_DATA_ERROR; }
+
+#define RC_INIT(buffer, bufferSize) Buffer = buffer; BufferLim = buffer + bufferSize; RC_INIT2
+ 
+#define RC_NORMALIZE if (Range < kTopValue) { RC_TEST; Range <<= 8; Code = (Code << 8) | RC_READ_BYTE; }
+
+#define IfBit0(p) RC_NORMALIZE; bound = (Range >> kNumBitModelTotalBits) * *(p); if (Code < bound)
+#define UpdateBit0(p) Range = bound; *(p) += (kBitModelTotal - *(p)) >> kNumMoveBits;
+#define UpdateBit1(p) Range -= bound; Code -= bound; *(p) -= (*(p)) >> kNumMoveBits;
+// #define UpdateBit0(p) Range = bound; *(p) = (CProb)(*(p) + ((kBitModelTotal - *(p)) >> kNumMoveBits));
+// #define UpdateBit1(p) Range -= bound; Code -= bound; *(p) = (CProb)(*(p) - (*(p) >> kNumMoveBits));
+
+int x86_2_Decode(
+    const Byte *buf0, SizeT size0, 
+    const Byte *buf1, SizeT size1, 
+    const Byte *buf2, SizeT size2, 
+    const Byte *buf3, SizeT size3, 
+    Byte *outBuf, SizeT outSize)
+{
+  CProb p[256 + 2];
+  SizeT inPos = 0, outPos = 0;
+
+  const Byte *Buffer, *BufferLim;
+  UInt32 Range, Code;
+  Byte prevByte = 0;
+
+  unsigned int i;
+  for (i = 0; i < sizeof(p) / sizeof(p[0]); i++)
+    p[i] = kBitModelTotal >> 1; 
+  RC_INIT(buf3, size3);
+
+  if (outSize == 0)
+    return BCJ2_RESULT_OK;
+
+  for (;;)
+  {
+    Byte b;
+    CProb *prob;
+    UInt32 bound;
+
+    SizeT limit = size0 - inPos;
+    if (outSize - outPos < limit)
+      limit = outSize - outPos;
+    while (limit != 0)
+    {
+      Byte b = buf0[inPos];
+      outBuf[outPos++] = b;
+      if (IsJ(prevByte, b))
+        break;
+      inPos++;
+      prevByte = b;
+      limit--;
+    }
+
+    if (limit == 0 || outPos == outSize)
+      break;
+
+    b = buf0[inPos++];
+
+    if (b == 0xE8)
+      prob = p + prevByte;
+    else if (b == 0xE9)
+      prob = p + 256;
+    else
+      prob = p + 257;
+
+    IfBit0(prob)
+    {
+      UpdateBit0(prob)
+      prevByte = b;
+    }
+    else
+    {
+      UInt32 dest;
+      const Byte *v;
+      UpdateBit1(prob)
+      if (b == 0xE8)
+      {
+        v = buf1;
+        if (size1 < 4)
+          return BCJ2_RESULT_DATA_ERROR;
+        buf1 += 4;
+        size1 -= 4;
+      }
+      else
+      {
+        v = buf2;
+        if (size2 < 4)
+          return BCJ2_RESULT_DATA_ERROR;
+        buf2 += 4;
+        size2 -= 4;
+      }
+      dest = (((UInt32)v[0] << 24) | ((UInt32)v[1] << 16) | 
+          ((UInt32)v[2] << 8) | ((UInt32)v[3])) - ((UInt32)outPos + 4);
+      outBuf[outPos++] = (Byte)dest;
+      if (outPos == outSize)
+        break;
+      outBuf[outPos++] = (Byte)(dest >> 8);
+      if (outPos == outSize)
+        break;
+      outBuf[outPos++] = (Byte)(dest >> 16);
+      if (outPos == outSize)
+        break;
+      outBuf[outPos++] = prevByte = (Byte)(dest >> 24);
+    }
+  }
+  return (outPos == outSize) ? BCJ2_RESULT_OK : BCJ2_RESULT_DATA_ERROR;
+}