ABT.Assign.CGenValue C# (CSharp) Method

        public override Reg CGenValue(CGenState state) {
            // 1. %eax = &left
            this.Left.CGenAddress(state);

            // 2. push %eax
            Int32 pos = state.CGenPushLong(Reg.EAX);

            Reg ret = this.Right.CGenValue(state);
            switch (this.Left.Type.Kind) {
                case ExprTypeKind.CHAR:
                case ExprTypeKind.UCHAR:
                    // pop %ebx
                    // now %ebx = %Left
                    state.CGenPopLong(pos, Reg.EBX);

                    // *%ebx = %al
                    state.MOVB(Reg.AL, 0, Reg.EBX);

                    return Reg.EAX;

                case ExprTypeKind.SHORT:
                case ExprTypeKind.USHORT:
                    // pop %ebx
                    // now %ebx = %Left
                    state.CGenPopLong(pos, Reg.EBX);

                    // *%ebx = %al
                    state.MOVW(Reg.AX, 0, Reg.EBX);

                    return Reg.EAX;

                case ExprTypeKind.LONG:
                case ExprTypeKind.ULONG:
                case ExprTypeKind.POINTER:
                    // pop %ebx
                    // now %ebx = &Left
                    state.CGenPopLong(pos, Reg.EBX);

                    // *%ebx = %al
                    state.MOVL(Reg.EAX, 0, Reg.EBX);

                    return Reg.EAX;

                case ExprTypeKind.FLOAT:
                    // pop %ebx
                    // now %ebx = &Left
                    state.CGenPopLong(pos, Reg.EBX);

                    // *%ebx = %st(0)
                    state.FSTS(0, Reg.EBX);

                    return Reg.ST0;

                case ExprTypeKind.DOUBLE:
                    // pop %ebx
                    // now %ebx = &Left
                    state.CGenPopLong(pos, Reg.EBX);

                    // *%ebx = %st(0)
                    state.FSTL(0, Reg.EBX);

                    return Reg.ST0;

                case ExprTypeKind.STRUCT_OR_UNION:
                    // pop %edi
                    // now %edi = &Left
                    state.CGenPopLong(pos, Reg.EDI);

                    // %esi = &Right
                    state.MOVL(Reg.EAX, Reg.ESI);

                    // %ecx = nbytes
                    state.MOVL(this.Left.Type.SizeOf, Reg.ECX);

                    state.CGenMemCpy();

                    // %eax = &Left
                    state.MOVL(Reg.EDI, Reg.EAX);

                    return Reg.EAX;

                case ExprTypeKind.FUNCTION:
                case ExprTypeKind.VOID:
                case ExprTypeKind.ARRAY:
                case ExprTypeKind.INCOMPLETE_ARRAY:
                default:
                    throw new InvalidProgramException("cannot assign to a " + this.Type.Kind);
            }
        }