using System;
using CPUx86 = Indy.IL2CPU.Assembler.X86;

namespace Cosmos.IL2CPU.X86.IL
{
	[Cosmos.IL2CPU.OpCode(ILOpCode.Code.Sub)]
	public class Sub: ILOp
	{
		public Sub(Cosmos.IL2CPU.Assembler aAsmblr):base(aAsmblr)
		{
		}

    public override void Execute(uint aMethodUID, ILOpCode aOpCode) {
      var stackTop = OldAsmblr.StackContents.Pop();

      if (stackTop.IsFloat) {
        throw new Exception("not implemented");
        return;
      }

      switch (stackTop.Size) {
        case 1:
        case 2:
        case 4:
          new CPUx86.Pop { DestinationReg = CPUx86.Registers.ECX };
          new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
          new CPUx86.Sub { DestinationReg = CPUx86.Registers.EAX, SourceReg = CPUx86.Registers.ECX };
          new CPUx86.Push { DestinationReg = CPUx86.Registers.EAX };
          break;
        case 8:
          new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
          new CPUx86.Pop { DestinationReg = CPUx86.Registers.EDX };
          new CPUx86.Sub { DestinationReg = CPUx86.Registers.ESP, DestinationIsIndirect = true, SourceReg = CPUx86.Registers.EAX };
          new CPUx86.SubWithCarry { DestinationReg = CPUx86.Registers.ESP, DestinationIsIndirect = true, DestinationDisplacement = 4, SourceReg = CPUx86.Registers.EDX };
          break;
        default:
          throw new Exception("not implemented");
          break;
      }
    }
		
	}
}