private string DecodeASMSingle(uint line, uint pc, bool useRegAliases)
{
_illegalFlag = false;
// Find the binary line and format
//string binaryLine = ASMValueHelper.HexToBinary_WithLength(line, 32);
//uint uBinaryLine = ASMValueHelper.BinaryToUnsigned(binaryLine);
EncodingFormat encFormat = FormatHelper.FindFormatByBinary(line);
// If we couldn't find the command, it's some kind of mystery! Either not included in
// the encoding file, or an illegal instruction.
if (encFormat == null)
{
_errorTextBuilder.AppendLine("WARNING: Unknown command: " + ASMValueHelper.UnsignedToHex_WithLength(line, 8).ToUpper());
return("unknown");
}
string newFormat = encFormat.ExpandedFormat;
string syntax = encFormat.Syntax;
string formatBinary = encFormat.Binary;
string newSyntax = syntax;
// Loop through syntax field and replace appropriate values
int regIndex = 0;
int immedIndex = 0;
string argValue = "";
//string binaryValue = "";
//string prevBinaryValue = "";
int numericValue = 0;
int prevNumericValue = 0;
int syntaxLength = syntax.Length;
int newIndex = 0;
for (int i = 0; i < syntaxLength; i++)
{
char c = syntax[i];
// If this is a register or immediate, find value to replace in the syntax for the decoding
if (char.IsLetter(c))
{
int metaType = ASMFormatHelper.FindElementMetaType(c);
if (metaType == ASMElementMetaType.Register)
{
char lookupChar = ASMStringHelper.CreateRegisterChar(regIndex);
//int vfpuRegMode = (c == ASMElementTypeCharacter.VFPURegister ? encFormat.VFPURegisterTypes[regIndex] : 0);
switch (c)
{
case ASMElementTypeCharacter.PartialVFPURegister:
argValue = DecodePartialVFPURegister(encFormat, line, regIndex, lookupChar);
break;
case ASMElementTypeCharacter.InvertedSingleBitVFPURegister:
numericValue = FindNumericArgValue(line, encFormat.RegisterPositions[regIndex], encFormat.RegisterIncludeMasks[regIndex]);
argValue = DecodeInvertedSingleBitVFPURegister(numericValue, encFormat.VFPURegisterTypes[regIndex]);
break;
case ASMElementTypeCharacter.VFPURegister:
numericValue = FindNumericArgValue(line, encFormat.RegisterPositions[regIndex], encFormat.RegisterIncludeMasks[regIndex]);
argValue = DecodeRegister(numericValue, c, useRegAliases, encFormat.VFPURegisterTypes[regIndex]);
break;
default:
//int binaryIndex = newFormat.IndexOf(lookupChar);
//binaryValue = binaryLine.Substring(binaryIndex, ASMRegisterHelper.GetEncodingBitLength(c));
numericValue = FindNumericArgValue(line, encFormat.RegisterPositions[regIndex], encFormat.RegisterIncludeMasks[regIndex]);
argValue = DecodeRegister(numericValue, c, useRegAliases, 0);
break;
}
regIndex++;
}
else if (metaType == ASMElementMetaType.Immediate)
{
char lookupChar = ASMStringHelper.CreateImmediateChar(immedIndex);
int binaryIndex = newFormat.IndexOf(lookupChar);
//prevBinaryValue = binaryValue;
prevNumericValue = numericValue;
int immedLength = encFormat.ImmediateLengths[immedIndex];
int hexLength = (immedLength + 3) / 4;
//binaryValue = binaryLine.Substring(binaryIndex, immedLength);
//numericValue = FindNumericArgValue(line, encFormat.ImmediatePositions[immedIndex], ASMValueHelper.GetIncludeMask(encFormat.ImmediateLengths[immedIndex]));
numericValue = FindNumericArgValue(line, encFormat.ImmediatePositions[immedIndex], encFormat.ImmediateIncludeMasks[immedIndex]);
switch (c)
{
case ASMElementTypeCharacter.SignedImmediate:
argValue = DecodeSignedImmediate(numericValue, hexLength);
break;
case ASMElementTypeCharacter.UnsignedImmediate:
argValue = DecodeUnsignedImmediate(numericValue, hexLength);
break;
case ASMElementTypeCharacter.BranchImmediate:
argValue = DecodeBranchImmediate(numericValue, pc);
break;
case ASMElementTypeCharacter.JumpImmediate:
argValue = DecodeJumpImmediate(numericValue, pc);
break;
case ASMElementTypeCharacter.DecrementedImmediate:
argValue = DecodeDecrementedImmediate(numericValue, hexLength);
break;
case ASMElementTypeCharacter.ModifiedImmediate:
argValue = DecodeModifiedImmediate(numericValue, prevNumericValue, hexLength);
break;
case ASMElementTypeCharacter.ShiftedImmediate:
argValue = DecodeShiftedImmediate(numericValue, encFormat.ShiftedImmediateAmounts[immedIndex], hexLength);
break;
case ASMElementTypeCharacter.VFPUPrefixImmediate:
argValue = DecodeVFPUPrefixImmediate(numericValue, encFormat.VFPUPrefixType);
break;
default: break;
}
immedIndex++;
}
// Replace character in syntax with correct value
newSyntax = ASMStringHelper.ReplaceCharAtIndex(newSyntax, newIndex, argValue);
newIndex += argValue.Length - 1;
}
newIndex++;
}
string spacing = string.IsNullOrEmpty(newSyntax) ? "" : " ";
string decoding = encFormat.Command + spacing + newSyntax;
if (_illegalFlag)
{
decoding = "illegal";
_errorTextBuilder.AppendLine(ASMStringHelper.Concat("Illegal instruction: ", line.ToString("x"), ": ", encFormat.Command.ToUpper(), " (", _illegalMessage, ")"));
}
return(decoding);
}