protected string[] generatePopFromStackToSegment(vmILParser.vmMemSegments segment, string IndexOperand, InstructionData currentVMinstruction)
{
var output = new List <String>();
if (segment == vmMemSegments._static)
{
output.AddRange(generateDecrement(stackPointer_symbol));
output.Add(assembler.CommandType.LOADAATPOINTER.ToString());
output.Add(stackPointer_symbol);
output.Add(assembler.CommandType.STOREA.ToString());
output.Add($"STATIC{currentVMinstruction.VMFilePath}.{currentVMinstruction.VMFunction}.{IndexOperand}");
}
else
{
//offset the base address of the symbol by the index
output.AddRange(generateIncrement(this.vmSegmentToSymbolName[segment], IndexOperand, updateSymbol: false));
output.AddRange(generateMoveAtoTemp());
output.AddRange(generateDecrement(stackPointer_symbol));
output.Add(assembler.CommandType.LOADAATPOINTER.ToString());
output.Add(stackPointer_symbol);
output.Add(assembler.CommandType.STOREAATPOINTER.ToString());
output.Add(temp_symbol);
}
return(output.ToArray());
}
protected string[] generatePushToStackFromSegment(vmILParser.vmMemSegments segment, string index, InstructionData currentVMinstruction)
{
//if we are writing from local to stack - we need to read from memory at the base address
//pointed to by the local symbol which is stored at LCL
//flow is LoadAFromPointer LCL - lets assume LCL holds the number 100 - which is the base address for the LCL segment
//then increment A by index
//store this in temp
var output = new List <String>();
//add LCL and index and store in A
//static is different from other segments
//we need to read a value from the symbol VMFILE.VMFUNCTION.INDEX
if (segment == vmMemSegments._static)
{
output.Add(assembler.CommandType.LOADA.ToString());
output.Add($"STATIC{currentVMinstruction.VMFilePath}.{currentVMinstruction.VMFunction}.{index}");
}
//if constant, then just load the constant specified into A.
else if (segment == vmMemSegments.constant)
{
output.Add(assembler.CommandType.LOADAIMMEDIATE.ToString());
output.Add(index);
}
else
{
output.AddRange(generateIncrement(vmSegmentToSymbolName[segment], index, updateSymbol: false));
output.Add(assembler.CommandType.STOREA.ToString());
output.Add(temp_symbol + " + 2");
output.Add(assembler.CommandType.LOADAATPOINTER.ToString());
output.Add(temp_symbol + " + 2");
}
//store it on the stack, and increment SP
output.Add(assembler.CommandType.STOREAATPOINTER.ToString());
output.Add(stackPointer_symbol);
output.AddRange(generateIncrement(stackPointer_symbol));
return(output.ToArray());
}
