private string DecodeBranchImmediate(int immedValue, uint pc)
{
//short difference = ASMValueHelper.BinaryToSignedShort(immedBinary);
//short difference = (short)immedValue;
//short difference = Convert.ToInt16((UInt16)immedValue);
ushort usValue = (ushort)immedValue;
short difference = ASMValueHelper.UnsignedShortToSignedShort(usValue);
//short difference = BitConverter.ToInt16(BitConverter.GetBytes(usValue), 0);
uint immed = (uint)(difference * 4 + pc + 4);
string strValue = ASMValueHelper.UnsignedToHex_WithLength(immed, 8).ToLower();
return("0x" + strValue);
}
private string DecodeSignedImmediate(int immedValue, int length)
{
//short immed = ASMValueHelper.BinaryToSignedShort(immedBinary);
//short immed = (short)immedValue;
//short immed = Convert.ToInt16((UInt16)immedValue);
//short immed = BitConverter.ToInt16(BitConverter.GetBytes((ushort)immedValue), 0);
ushort usValue = (ushort)immedValue;
short immed = ASMValueHelper.UnsignedShortToSignedShort(usValue);
uint uImmed = (uint)((immed < 0) ? (immed * -1) : immed);
return(((immed < 0) ? "-0x" : "0x") + ASMValueHelper.UnsignedToHex_WithLength(uImmed, length).ToLower());
}
public byte[] UpdateBlockReferences(byte[] bytes, uint pc, bool littleEndian, IEnumerable <BlockMove> blockMoves)
{
int byteCount = bytes.Length;
if (byteCount < 4)
{
return(bytes);
}
byte[] resultBytes = new byte[byteCount];
int startIndex = 0;
byte[] asmBytes = bytes;
if (byteCount > 4)
{
uint offsetBytes = pc % 4;
if (offsetBytes != 0)
{
uint skipBytes = 4 - offsetBytes;
pc = pc + skipBytes;
startIndex += (int)skipBytes;
int length = (int)(bytes.Length - skipBytes);
byte[] newBytes = new byte[length];
Array.Copy(bytes, skipBytes, newBytes, 0, length);
Array.Copy(bytes, 0, resultBytes, 0, startIndex);
asmBytes = newBytes;
}
}
uint[] instructions = ASMValueHelper.GetUintArrayFromBytes(asmBytes, littleEndian);
int numInstructions = instructions.Length;
uint[] newInstructions = new uint[numInstructions];
uint[] regLuiValues = new uint[32];
int[] regLuiIndexes = new int[32];
for (int regNum = 0; regNum < 32; regNum++)
{
regLuiIndexes[regNum] = -1;
}
for (int index = 0; index < numInstructions; index++)
{
uint uBinaryLine = instructions[index];
uint opcode = (uBinaryLine >> 26);
uint newInstruction = uBinaryLine;
// Is unconditional jump literal command J or JAL
if ((opcode & 0x3E) == 0x02) // ((opcode & 0b111110) == 0b000010)
{
uint jumpAddress = (((uBinaryLine & 0x03FFFFFFU) << 2) | (pc & 0xF0000000U));
foreach (BlockMove blockMove in blockMoves)
{
if ((jumpAddress >= blockMove.Location) && (jumpAddress < blockMove.EndLocation))
{
uint newJumpAddress = (uint)(jumpAddress + blockMove.Offset);
newInstruction = (opcode << 26) | ((newJumpAddress >> 2) & 0x03FFFFFFU);
}
}
}
// Is Load Upper Immediate (LUI)
EncodingFormat encFormat = Decoder.FormatHelper.FindFormatByBinary(uBinaryLine);
if (encFormat.Command == "lui")
{
int regNum = (int)(uBinaryLine >> encFormat.RegisterPositions[0] & encFormat.RegisterIncludeMasks[0]);
uint immediate = (uint)(uBinaryLine >> encFormat.ImmediatePositions[0] & encFormat.ImmediateIncludeMasks[0]);
regLuiValues[regNum] = immediate;
regLuiIndexes[regNum] = index;
}
// Is Load or Store command, or ADDI, ADDIU, or ORI
if (IsLoadCommand(encFormat.Command) || IsStoreCommand(encFormat.Command) || ((encFormat.Command == "addi") || (encFormat.Command == "addiu") || (encFormat.Command == "ori")))
{
int regNum = (int)(uBinaryLine >> encFormat.RegisterPositions[1] & encFormat.RegisterIncludeMasks[1]);
if (regLuiIndexes[regNum] >= 0)
{
short offset = ASMValueHelper.UnsignedShortToSignedShort((ushort)(uBinaryLine & 0xffff));
uint targetAddress = (uint)((regLuiValues[regNum] << 16) + offset) | (0x80000000U);
foreach (BlockMove blockMove in blockMoves)
{
if ((targetAddress >= blockMove.Location) && (targetAddress < blockMove.EndLocation))
{
uint newTargetAddress = (uint)(targetAddress + blockMove.Offset);
uint newLuiValue = (ushort)(newTargetAddress >> 16);
ushort newOffset = (ushort)(newTargetAddress & 0xffff);
if (encFormat.Command != "ori")
{
newLuiValue += (uint)((newOffset >= 0x8000) ? 1 : 0);
}
newInstruction = ((uBinaryLine & 0xFFFF0000U) | newOffset);
// Modify the LUI if necessary
if (newLuiValue != regLuiValues[regNum])
{
uint newLuiInstruction = (newInstructions[regLuiIndexes[regNum]] & 0xFFFF0000U) | newLuiValue;
newInstructions[regLuiIndexes[regNum]] = newLuiInstruction;
byte[] newLuiInstructionBytes = ASMValueHelper.ConvertUIntToBytes(newLuiInstruction, littleEndian);
Array.Copy(newLuiInstructionBytes, 0, resultBytes, (regLuiIndexes[regNum] * 4) + startIndex, 4);
}
}
}
}
}
newInstructions[index] = newInstruction;
byte[] newBytes = ASMValueHelper.ConvertUIntToBytes(newInstruction, littleEndian);
Array.Copy(newBytes, 0, resultBytes, (index * 4) + startIndex, 4);
}
for (int index = (numInstructions * 4) + startIndex; index < byteCount; index++)
{
resultBytes[index] = bytes[index];
}
return(resultBytes);
}
