/* BraIA64.c -- Converter for IA-64 code
 2008-10-04 : Igor Pavlov : Public domain */
 
 #include "Bra.h"
 
 static const Byte kBranchTable[32] =
 {
   0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,
   4, 4, 6, 6, 0, 0, 7, 7,
   4, 4, 0, 0, 4, 4, 0, 0
 };
 
 SizeT IA64_Convert(Byte *data, SizeT size, UInt32 ip, int encoding)
 {
   SizeT i;
   if (size < 16)
     return 0;
   size -= 16;
   for (i = 0; i <= size; i += 16)
   {
     UInt32 instrTemplate = data[i] & 0x1F;
     UInt32 mask = kBranchTable[instrTemplate];
     UInt32 bitPos = 5;
     int slot;
     for (slot = 0; slot < 3; slot++, bitPos += 41)
     {
       UInt32 bytePos, bitRes;
       UInt64 instruction, instNorm;
       int j;
       if (((mask >> slot) & 1) == 0)
         continue;
       bytePos = (bitPos >> 3);
       bitRes = bitPos & 0x7;
       instruction = 0;
       for (j = 0; j < 6; j++)
         instruction += (UInt64)data[i + j + bytePos] << (8 * j);
 
       instNorm = instruction >> bitRes;
       if (((instNorm >> 37) & 0xF) == 0x5 && ((instNorm >> 9) & 0x7) == 0)
       {
         UInt32 src = (UInt32)((instNorm >> 13) & 0xFFFFF);
         UInt32 dest;
         src |= ((UInt32)(instNorm >> 36) & 1) << 20;
         
         src <<= 4;
         
         if (encoding)
           dest = ip + (UInt32)i + src;
         else
           dest = src - (ip + (UInt32)i);
         
         dest >>= 4;
         
         instNorm &= ~((UInt64)(0x8FFFFF) << 13);
         instNorm |= ((UInt64)(dest & 0xFFFFF) << 13);
         instNorm |= ((UInt64)(dest & 0x100000) << (36 - 20));
         
         instruction &= (1 << bitRes) - 1;
         instruction |= (instNorm << bitRes);
         for (j = 0; j < 6; j++)
           data[i + j + bytePos] = (Byte)(instruction >> (8 * j));
       }
     }
   }
   return i;
 }