CodeGeneration.CGenState.RequestLabel C# (CSharp) Method

        public Int32 RequestLabel() {
            return this.label_idx++;
        }

        // 
        //          test Cond
        //          jz false ---+
        //          true_expr   |
        // +------- jmp finish  |
        // |    false: <--------+
        // |        false_expr
        // +--> finish:
        // 
        public override Reg CGenValue(CGenState state) {
            Int32 stack_size = state.StackSize;
            Reg ret = this.Cond.CGenValue(state);
            state.CGenForceStackSizeTo(stack_size);

            // test Cond
            switch (ret) {
                case Reg.EAX:
                    state.TESTL(Reg.EAX, Reg.EAX);
                    break;

                case Reg.ST0:
                    /// Compare Expr with 0.0
                    /// < see cref = "BinaryComparisonOp.OperateFloat(CGenState)" />
                    state.FLDZ();
                    state.FUCOMIP();
                    state.FSTP(Reg.ST0);
                    break;

                default:
                    throw new InvalidProgramException();
            }

            Int32 false_label = state.RequestLabel();
            Int32 finish_label = state.RequestLabel();

            state.JZ(false_label);

            this.TrueExpr.CGenValue(state);

            state.JMP(finish_label);

            state.CGenLabel(false_label);

            ret = this.FalseExpr.CGenValue(state);

            state.CGenLabel(finish_label);

            return ret;
        }