public override void Compile(Assembly assembly, Scope scope, Register target)
{
throw new CompileError("Comparisons in general expressions are not implemented");
//Evaluate in reverse in case both need to go on the stack
var secondTarget = scope.FindFreeRegister();
if (Scope.IsRegister((Register)secondTarget)) scope.UseRegister(secondTarget);
(ChildNodes[1] as CompilableNode).Compile(assembly, scope, (Register)secondTarget);
if (AsString == "==" || AsString == "!=")
{
(ChildNodes[0] as CompilableNode).Compile(assembly, scope, Register.STACK);
if (target == Register.STACK)
{
assembly.Add("SET", Scope.TempRegister, "0x0", "Equality onto stack");
assembly.Add((AsString == "==" ? "IFE" : "IFN"), "POP", Scope.GetRegisterLabelSecond(secondTarget));
assembly.Add("SET", Scope.TempRegister, "0x1");
assembly.Add("SET", "PUSH", Scope.TempRegister);
}
else
{
assembly.Add("SET", Scope.GetRegisterLabelFirst((int)target), "0x0", "Equality into register");
assembly.Add((AsString == "==" ? "IFE" : "IFN"), "POP", Scope.GetRegisterLabelSecond(secondTarget));
assembly.Add("SET", Scope.GetRegisterLabelFirst((int)target), "0x1");
}
}
if (secondTarget == (int)Register.STACK)
scope.stackDepth -= 1;
else
scope.FreeRegister(secondTarget);
}
public override void Init(Irony.Parsing.ParsingContext context, Irony.Parsing.ParseTreeNode treeNode)
{
base.Init(context, treeNode);
AddChild("Block", treeNode.ChildNodes[3]);
localScope = new Scope();
var parameters = treeNode.ChildNodes[2].ChildNodes;
for (int i = 0; i < parameters.Count; ++i)
{
var variable = new Variable();
variable.scope = localScope;
variable.name = parameters[i].ChildNodes[0].FindTokenAndGetText();
localScope.variables.Add(variable);
if (i < 3)
{
variable.location = (Register)i;
localScope.UseRegister(i);
}
else
{
variable.location = Register.STACK;
variable.stackOffset = localScope.stackDepth;
localScope.stackDepth += 1;
}
parameterCount += 1;
}
this.AsString = treeNode.ChildNodes[1].FindTokenAndGetText();
label = Scope.GetLabel() + "_" + AsString;
localScope.activeFunction = this;
}
public override void Compile(Assembly assembly, Scope scope, Register target)
{
var func = findFunction(this, AsString);
if (func == null) throw new CompileError("Can't find function - " + AsString);
if (func.parameterCount != ChildNodes.Count) throw new CompileError("Incorrect number of arguments - " + AsString);
func.references += 1;
//Marshall registers
var startingRegisterState = scope.SaveRegisterState();
for (int i = 0; i < 3; ++i)
{
if (startingRegisterState[i] == RegisterState.Used)
{
PushRegister(assembly, scope, (Register)i);
if (scope.activeFunction != null && scope.activeFunction.parameterCount > i)
{
scope.activeFunction.localScope.variables[i].location = Register.STACK;
scope.activeFunction.localScope.variables[i].stackOffset = scope.stackDepth - 1;
}
}
if (func.parameterCount > i)
{
scope.UseRegister(i);
(ChildNodes[i] as CompilableNode).Compile(assembly, scope, (Register)i);
}
}
for (int i = 3; i < 7; ++i)
if (startingRegisterState[i] == RegisterState.Used)
PushRegister(assembly, scope, (Register)i);
if (func.parameterCount > 3)
for (int i = 3; i < func.parameterCount; ++i)
(ChildNodes[i] as CompilableNode).Compile(assembly, scope, Register.STACK);
assembly.Add("JSR", func.label, "", "Calling function");
if (func.parameterCount > 3) //Need to remove parameters from stack
{
assembly.Add("ADD", "SP", hex(func.parameterCount - 3), "Remove parameters");
scope.stackDepth -= (func.parameterCount - 3);
}
if (scope.activeFunction != null)
for (int i = 0; i < 3 && i < scope.activeFunction.parameterCount; ++i)
scope.activeFunction.localScope.variables[i].location = (Register)i;
var saveA = startingRegisterState[0] == RegisterState.Used;
if (saveA && target != Register.DISCARD) assembly.Add("SET", Scope.TempRegister, "A", "Save return value from being overwritten by stored register");
for (int i = 6; i >= 0; --i)
{
if (startingRegisterState[i] == RegisterState.Used)
{
assembly.Add("SET", Scope.GetRegisterLabelFirst(i), "POP", "Restoring register");
scope.UseRegister(i);
scope.stackDepth -= 1;
}
}
if (target == Register.A && !saveA) return;
else if (Scope.IsRegister(target)) assembly.Add("SET", Scope.GetRegisterLabelFirst((int)target), saveA ? Scope.TempRegister : "A");
else if (target == Register.STACK)
{
assembly.Add("SET", "PUSH", saveA ? Scope.TempRegister : "A", "Put return value on stack");
scope.stackDepth += 1;
}
}