// We will use standard x86-64 conventions -> RDI, RSI, RDX, RCX, R8, R9.
// TODO: instruction templates covering hw register modifications
public ILabel GenerateCall(
ILocation result,
IEnumerable <VirtualRegister> callArguments,
ILabel onReturn,
Function.Function callerFunction,
Function.Function function)
{
var needStackOffset = function.GetStackArgumentsCount() % 2 == 1 ? 8 : 0;
var preCall = new List <Node>
{
new AlignStackPointer(needStackOffset)
}
.Append(new Comment("Pass arguments"))
.Concat(this.PassArguments(callerFunction, callArguments, function.Parent))
.Append(new ClearDF())
.Append(new Comment($"Call {function.MangledName}"))
.Append(
new UsesDefinesNode(
HardwareRegisterUtils.ArgumentRegisters.Take(callArguments.Count() + 1).ToList(),
HardwareRegisterUtils.CallerSavedRegisters));
var postCall = new List <Node>
{
new Comment("Copy function result to variable"),
this.readWriteGenerator.GenerateWrite(callerFunction, result, new RegisterRead(HardwareRegister.RAX)),
new Comment("Restore RSP alignment"),
new AlignStackPointer(-(needStackOffset + (8 * function.GetStackArgumentsCount()))),
new Comment("End of call"),
};
var controlFlow = new FunctionCall(function, postCall.MakeTreeChain(this.labelFactory, onReturn));
return(preCall.MakeTreeChain(this.labelFactory, controlFlow));
}
private List <Node> GetArgumentSources(Function.Function function)
{
var registerArguments = HardwareRegisterUtils
.ArgumentRegisters
.Select(reg => new RegisterRead(reg));
var memoryArguments = Enumerable.Range(0, function.GetStackArgumentsCount())
.Select(n => (Node) new MemoryRead(HardwareRegister.RBP.OffsetAddress(n + 2)));
return(registerArguments.Concat(memoryArguments).ToList());
}