'21.07'21.07

1 files changed, 257 insertions, 0 deletions

diff --git a/C/Bcj2.c b/C/Bcj2.c
new file mode 100644
index 0000000..c7b9567
--- /dev/null
+++ b/C/Bcj2.c
@@ -0,0 +1,257 @@
+/* Bcj2.c -- BCJ2 Decoder (Converter for x86 code)
+2021-02-09 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include "Bcj2.h"
+#include "CpuArch.h"
+
+#define CProb UInt16
+
+#define kTopValue ((UInt32)1 << 24)
+#define kNumModelBits 11
+#define kBitModelTotal (1 << kNumModelBits)
+#define kNumMoveBits 5
+
+#define _IF_BIT_0 ttt = *prob; bound = (p->range >> kNumModelBits) * ttt; if (p->code < bound)
+#define _UPDATE_0 p->range = bound; *prob = (CProb)(ttt + ((kBitModelTotal - ttt) >> kNumMoveBits));
+#define _UPDATE_1 p->range -= bound; p->code -= bound; *prob = (CProb)(ttt - (ttt >> kNumMoveBits));
+
+void Bcj2Dec_Init(CBcj2Dec *p)
+{
+  unsigned i;
+
+  p->state = BCJ2_DEC_STATE_OK;
+  p->ip = 0;
+  p->temp[3] = 0;
+  p->range = 0;
+  p->code = 0;
+  for (i = 0; i < sizeof(p->probs) / sizeof(p->probs[0]); i++)
+    p->probs[i] = kBitModelTotal >> 1;
+}
+
+SRes Bcj2Dec_Decode(CBcj2Dec *p)
+{
+  if (p->range <= 5)
+  {
+    p->state = BCJ2_DEC_STATE_OK;
+    for (; p->range != 5; p->range++)
+    {
+      if (p->range == 1 && p->code != 0)
+        return SZ_ERROR_DATA;
+      
+      if (p->bufs[BCJ2_STREAM_RC] == p->lims[BCJ2_STREAM_RC])
+      {
+        p->state = BCJ2_STREAM_RC;
+        return SZ_OK;
+      }
+
+      p->code = (p->code << 8) | *(p->bufs[BCJ2_STREAM_RC])++;
+    }
+    
+    if (p->code == 0xFFFFFFFF)
+      return SZ_ERROR_DATA;
+    
+    p->range = 0xFFFFFFFF;
+  }
+  else if (p->state >= BCJ2_DEC_STATE_ORIG_0)
+  {
+    while (p->state <= BCJ2_DEC_STATE_ORIG_3)
+    {
+      Byte *dest = p->dest;
+      if (dest == p->destLim)
+        return SZ_OK;
+      *dest = p->temp[(size_t)p->state - BCJ2_DEC_STATE_ORIG_0];
+      p->state++;
+      p->dest = dest + 1;
+    }
+  }
+
+  /*
+  if (BCJ2_IS_32BIT_STREAM(p->state))
+  {
+    const Byte *cur = p->bufs[p->state];
+    if (cur == p->lims[p->state])
+      return SZ_OK;
+    p->bufs[p->state] = cur + 4;
+    
+    {
+      UInt32 val;
+      Byte *dest;
+      SizeT rem;
+      
+      p->ip += 4;
+      val = GetBe32(cur) - p->ip;
+      dest = p->dest;
+      rem = p->destLim - dest;
+      if (rem < 4)
+      {
+        SizeT i;
+        SetUi32(p->temp, val);
+        for (i = 0; i < rem; i++)
+          dest[i] = p->temp[i];
+        p->dest = dest + rem;
+        p->state = BCJ2_DEC_STATE_ORIG_0 + (unsigned)rem;
+        return SZ_OK;
+      }
+      SetUi32(dest, val);
+      p->temp[3] = (Byte)(val >> 24);
+      p->dest = dest + 4;
+      p->state = BCJ2_DEC_STATE_OK;
+    }
+  }
+  */
+
+  for (;;)
+  {
+    if (BCJ2_IS_32BIT_STREAM(p->state))
+      p->state = BCJ2_DEC_STATE_OK;
+    else
+    {
+      if (p->range < kTopValue)
+      {
+        if (p->bufs[BCJ2_STREAM_RC] == p->lims[BCJ2_STREAM_RC])
+        {
+          p->state = BCJ2_STREAM_RC;
+          return SZ_OK;
+        }
+        p->range <<= 8;
+        p->code = (p->code << 8) | *(p->bufs[BCJ2_STREAM_RC])++;
+      }
+
+      {
+        const Byte *src = p->bufs[BCJ2_STREAM_MAIN];
+        const Byte *srcLim;
+        Byte *dest;
+        SizeT num = (SizeT)(p->lims[BCJ2_STREAM_MAIN] - src);
+        
+        if (num == 0)
+        {
+          p->state = BCJ2_STREAM_MAIN;
+          return SZ_OK;
+        }
+        
+        dest = p->dest;
+        if (num > (SizeT)(p->destLim - dest))
+        {
+          num = (SizeT)(p->destLim - dest);
+          if (num == 0)
+          {
+            p->state = BCJ2_DEC_STATE_ORIG;
+            return SZ_OK;
+          }
+        }
+       
+        srcLim = src + num;
+
+        if (p->temp[3] == 0x0F && (src[0] & 0xF0) == 0x80)
+          *dest = src[0];
+        else for (;;)
+        {
+          Byte b = *src;
+          *dest = b;
+          if (b != 0x0F)
+          {
+            if ((b & 0xFE) == 0xE8)
+              break;
+            dest++;
+            if (++src != srcLim)
+              continue;
+            break;
+          }
+          dest++;
+          if (++src == srcLim)
+            break;
+          if ((*src & 0xF0) != 0x80)
+            continue;
+          *dest = *src;
+          break;
+        }
+        
+        num = (SizeT)(src - p->bufs[BCJ2_STREAM_MAIN]);
+        
+        if (src == srcLim)
+        {
+          p->temp[3] = src[-1];
+          p->bufs[BCJ2_STREAM_MAIN] = src;
+          p->ip += (UInt32)num;
+          p->dest += num;
+          p->state =
+            p->bufs[BCJ2_STREAM_MAIN] ==
+            p->lims[BCJ2_STREAM_MAIN] ?
+              (unsigned)BCJ2_STREAM_MAIN :
+              (unsigned)BCJ2_DEC_STATE_ORIG;
+          return SZ_OK;
+        }
+        
+        {
+          UInt32 bound, ttt;
+          CProb *prob;
+          Byte b = src[0];
+          Byte prev = (Byte)(num == 0 ? p->temp[3] : src[-1]);
+          
+          p->temp[3] = b;
+          p->bufs[BCJ2_STREAM_MAIN] = src + 1;
+          num++;
+          p->ip += (UInt32)num;
+          p->dest += num;
+          
+          prob = p->probs + (unsigned)(b == 0xE8 ? 2 + (unsigned)prev : (b == 0xE9 ? 1 : 0));
+          
+          _IF_BIT_0
+          {
+            _UPDATE_0
+            continue;
+          }
+          _UPDATE_1
+            
+        }
+      }
+    }
+
+    {
+      UInt32 val;
+      unsigned cj = (p->temp[3] == 0xE8) ? BCJ2_STREAM_CALL : BCJ2_STREAM_JUMP;
+      const Byte *cur = p->bufs[cj];
+      Byte *dest;
+      SizeT rem;
+      
+      if (cur == p->lims[cj])
+      {
+        p->state = cj;
+        break;
+      }
+      
+      val = GetBe32(cur);
+      p->bufs[cj] = cur + 4;
+
+      p->ip += 4;
+      val -= p->ip;
+      dest = p->dest;
+      rem = (SizeT)(p->destLim - dest);
+      
+      if (rem < 4)
+      {
+        p->temp[0] = (Byte)val; if (rem > 0) dest[0] = (Byte)val; val >>= 8;
+        p->temp[1] = (Byte)val; if (rem > 1) dest[1] = (Byte)val; val >>= 8;
+        p->temp[2] = (Byte)val; if (rem > 2) dest[2] = (Byte)val; val >>= 8;
+        p->temp[3] = (Byte)val;
+        p->dest = dest + rem;
+        p->state = BCJ2_DEC_STATE_ORIG_0 + (unsigned)rem;
+        break;
+      }
+      
+      SetUi32(dest, val);
+      p->temp[3] = (Byte)(val >> 24);
+      p->dest = dest + 4;
+    }
+  }
+
+  if (p->range < kTopValue && p->bufs[BCJ2_STREAM_RC] != p->lims[BCJ2_STREAM_RC])
+  {
+    p->range <<= 8;
+    p->code = (p->code << 8) | *(p->bufs[BCJ2_STREAM_RC])++;
+  }
+
+  return SZ_OK;
+}