SCIP in C++11 ― 3.3.4節その3

事象駆動シミューレションその3： デジタル回路のシミュレータその3：繰り上がり伝搬加算器と 問題3.30

途中の繰り上がり信号C_iが、前後両方の全加算器に絡むのでなければ、

accumulate一発ですむところだが、絡むので、丁寧に再帰を書く。

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const List rippleCarryAdder

(const List& aWires, const List& bWires,

 const List& sumWires,const List& carryWire)

{

    const int order(length(aWires));

    if(order!=length(bWires)||order!=length(sumWires)){

        cerr<<"lengths of bits must be same ("

            <<order<<" , "<<length(bWires)<<" , "

            <<length(sumWires)<<")."<<endl;

        exit(1);

    }

    const List cWires

        (cons(carryWire,

              mapping

              (function<List(List)>

               ([](const List& counter){

                   return(makeLeaf(makeWire()));

               }),enumerateInterval(1,order))));

    function<void(List,List,List,List)> connectFullAdders;

    connectFullAdders=[&connectFullAdders]

        (const List& ai, const List& bi, const List& ciMinus1, const List& si){

        if(!isNull(ai)){

            fullAdder

                (executable<List,List>(car(ai)),

                 executable<List,List>(car(bi)),

                 executable<List,List>(cadr(ciMinus1)),

                 executable<List,List>(car(si)),

                 executable<List,List>(car(ciMinus1)));

            connectFullAdders(cdr(ai),cdr(bi),cdr(ciMinus1),cdr(si));

        }

    };

    connectFullAdders(aWires,bWires,cWires,sumWires);

    return(makeLeaf("OK"));

}

const List makeWireList(const List& signalList)

{

    return

        (mapping

         (function<List(List)>

          ([](const List& signal){

              const Wire signalWire(makeWire());

              setfSignal(signalWire,signal);

              return(makeLeaf(signalWire));

          }),signalList));

          

}

const List getWireListSignals(const List& wireList)

{

    return

        (mapping

         (function<List(List)>

          ([](const List& wireLeaf){

              return(getSignal(executable<List,List>(wireLeaf)));

          }),wireList));

          

}

int main(int argc, char** argv)

{

    cout<<"Excersize 3.30:"<<endl;

    const auto aWires(makeWireList(makeList(1,0,1)));

    const auto bWires(makeWireList(makeList(0,1,1)));

    const auto sumWires(makeWireList(makeList(0,0,0)));

    const auto carryWire(makeWire());

    rippleCarryAdder(aWires,bWires,sumWires,makeLeaf(carryWire));

    propagate();

    cout<<listString(getWireListSignals(aWires))<<"+"

        <<listString(getWireListSignals(bWires))<<":"<<endl;

    cout<<"carry = "<<listString(getSignal(carryWire))

        <<", sum = "<<listString(getWireListSignals(sumWires))<<endl;

    return(0);

}

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出力

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Excersize 3.30:

(1 0 1)+(0 1 1):

carry = 1, sum = (0 0 0)