'21.07'21.07

1 files changed, 82 insertions, 0 deletions

diff --git a/C/Bra86.c b/C/Bra86.c
new file mode 100644
index 0000000..10a0fbd
--- /dev/null
+++ b/C/Bra86.c
@@ -0,0 +1,82 @@
+/* Bra86.c -- Converter for x86 code (BCJ)
+2021-02-09 : Igor Pavlov : Public domain */
+
+#include "Precomp.h"
+
+#include "Bra.h"
+
+#define Test86MSByte(b) ((((b) + 1) & 0xFE) == 0)
+
+SizeT x86_Convert(Byte *data, SizeT size, UInt32 ip, UInt32 *state, int encoding)
+{
+  SizeT pos = 0;
+  UInt32 mask = *state & 7;
+  if (size < 5)
+    return 0;
+  size -= 4;
+  ip += 5;
+
+  for (;;)
+  {
+    Byte *p = data + pos;
+    const Byte *limit = data + size;
+    for (; p < limit; p++)
+      if ((*p & 0xFE) == 0xE8)
+        break;
+
+    {
+      SizeT d = (SizeT)(p - data) - pos;
+      pos = (SizeT)(p - data);
+      if (p >= limit)
+      {
+        *state = (d > 2 ? 0 : mask >> (unsigned)d);
+        return pos;
+      }
+      if (d > 2)
+        mask = 0;
+      else
+      {
+        mask >>= (unsigned)d;
+        if (mask != 0 && (mask > 4 || mask == 3 || Test86MSByte(p[(size_t)(mask >> 1) + 1])))
+        {
+          mask = (mask >> 1) | 4;
+          pos++;
+          continue;
+        }
+      }
+    }
+
+    if (Test86MSByte(p[4]))
+    {
+      UInt32 v = ((UInt32)p[4] << 24) | ((UInt32)p[3] << 16) | ((UInt32)p[2] << 8) | ((UInt32)p[1]);
+      UInt32 cur = ip + (UInt32)pos;
+      pos += 5;
+      if (encoding)
+        v += cur;
+      else
+        v -= cur;
+      if (mask != 0)
+      {
+        unsigned sh = (mask & 6) << 2;
+        if (Test86MSByte((Byte)(v >> sh)))
+        {
+          v ^= (((UInt32)0x100 << sh) - 1);
+          if (encoding)
+            v += cur;
+          else
+            v -= cur;
+        }
+        mask = 0;
+      }
+      p[1] = (Byte)v;
+      p[2] = (Byte)(v >> 8);
+      p[3] = (Byte)(v >> 16);
+      p[4] = (Byte)(0 - ((v >> 24) & 1));
+    }
+    else
+    {
+      mask = (mask >> 1) | 4;
+      pos++;
+    }
+  }
+}