C++ DistMatrix::RowRank方法代碼示例

void TranslateBetweenGrids
( const DistMatrix<T,MC,MR>& A, DistMatrix<T,MC,MR>& B ) 
{
    DEBUG_ONLY(CSE cse("copy::TranslateBetweenGrids [MC,MR]"))

    B.Resize( A.Height(), A.Width() );
    // Just need to ensure that each viewing comm contains the other team's
    // owning comm. Congruence is too strong.

    // Compute the number of process rows and columns that each process
    // needs to send to.
    const Int colStride = B.ColStride();
    const Int rowStride = B.RowStride();
    const Int colRank = B.ColRank();
    const Int rowRank = B.RowRank();
    const Int colStrideA = A.ColStride();
    const Int rowStrideA = A.RowStride();
    const Int colGCD = GCD( colStride, colStrideA );
    const Int rowGCD = GCD( rowStride, rowStrideA );
    const Int colLCM = colStride*colStrideA / colGCD;
    const Int rowLCM = rowStride*rowStrideA / rowGCD;
    const Int numColSends = colStride / colGCD;
    const Int numRowSends = rowStride / rowGCD;

    const Int colAlign = B.ColAlign();
    const Int rowAlign = B.RowAlign();
    const Int colAlignA = A.ColAlign();
    const Int rowAlignA = A.RowAlign();

    const bool inBGrid = B.Participating();
    const bool inAGrid = A.Participating();
    if( !inBGrid && !inAGrid )
        return;

    const Int maxSendSize =
        (A.Height()/(colStrideA*numColSends)+1) *
        (A.Width()/(rowStrideA*numRowSends)+1);

    // Translate the ranks from A's VC communicator to B's viewing so that
    // we can match send/recv communicators. Since A's VC communicator is not
    // necessarily defined on every process, we instead work with A's owning
    // group and account for row-major ordering if necessary.
    const int sizeA = A.Grid().Size();
    vector<int> rankMap(sizeA), ranks(sizeA);
    if( A.Grid().Order() == COLUMN_MAJOR )
    {
        for( int j=0; j<sizeA; ++j )
            ranks[j] = j;
    }
    else
    {
        // The (i,j) = i + j*colStrideA rank in the column-major ordering is
        // equal to the j + i*rowStrideA rank in a row-major ordering.
        // Since we desire rankMap[i+j*colStrideA] to correspond to process
        // (i,j) in A's grid's rank in this viewing group, ranks[i+j*colStrideA]
        // should correspond to process (i,j) in A's owning group. Since the
        // owning group is ordered row-major in this case, its rank is
        // j+i*rowStrideA. Note that setting
        // ranks[j+i*rowStrideA] = i+j*colStrideA is *NOT* valid.
        for( int i=0; i<colStrideA; ++i )
            for( int j=0; j<rowStrideA; ++j )
                ranks[i+j*colStrideA] = j+i*rowStrideA;
    }
    mpi::Translate
    ( A.Grid().OwningGroup(), sizeA, &ranks[0],
      B.Grid().ViewingComm(), &rankMap[0] );

    // Have each member of A's grid individually send to all numRow x numCol
    // processes in order, while the members of this grid receive from all
    // necessary processes at each step.
    Int requiredMemory = 0;
    if( inAGrid )
        requiredMemory += maxSendSize;
    if( inBGrid )
        requiredMemory += maxSendSize;
    vector<T> auxBuf( requiredMemory );
    Int offset = 0;
    T* sendBuf = &auxBuf[offset];
    if( inAGrid )
        offset += maxSendSize;
    T* recvBuf = &auxBuf[offset];

    Int recvRow = 0; // avoid compiler warnings...
    if( inAGrid )
        recvRow = Mod(Mod(A.ColRank()-colAlignA,colStrideA)+colAlign,colStride);
    for( Int colSend=0; colSend<numColSends; ++colSend )
    {
        Int recvCol = 0; // avoid compiler warnings...
        if( inAGrid )
            recvCol=Mod(Mod(A.RowRank()-rowAlignA,rowStrideA)+rowAlign,
                        rowStride);
        for( Int rowSend=0; rowSend<numRowSends; ++rowSend )
        {
            mpi::Request sendRequest;
            // Fire off this round of non-blocking sends
            if( inAGrid )
            {
                // Pack the data
                Int sendHeight = Length(A.LocalHeight(),colSend,numColSends);
                Int sendWidth = Length(A.LocalWidth(),rowSend,numRowSends);
//.........這裏部分代碼省略.........

void TransposeDist( const DistMatrix<T,U,V>& A, DistMatrix<T,V,U>& B ) 
{
    DEBUG_ONLY(CSE cse("copy::TransposeDist"))
    AssertSameGrids( A, B );

    const Grid& g = B.Grid();
    B.Resize( A.Height(), A.Width() );
    if( !B.Participating() )
        return;

    const Int colStrideA = A.ColStride();
    const Int rowStrideA = A.RowStride();
    const Int distSize = A.DistSize();

    if( A.DistSize() == 1 && B.DistSize() == 1 ) 
    {
        Copy( A.LockedMatrix(), B.Matrix() );
    }
    else if( A.Width() == 1 )
    {
        const Int height = A.Height();
        const Int maxLocalHeight = MaxLength(height,distSize);
        const Int portionSize = mpi::Pad( maxLocalHeight );

        const Int colDiff = Shift(A.DistRank(),A.ColAlign(),distSize) - 
                            Shift(B.DistRank(),B.ColAlign(),distSize);
        const Int sendRankB = Mod( B.DistRank()+colDiff, distSize );
        const Int recvRankA = Mod( A.DistRank()-colDiff, distSize );
        const Int recvRankB = 
            (recvRankA/colStrideA)+rowStrideA*(recvRankA%colStrideA);

        vector<T> buffer;
        FastResize( buffer, (colStrideA+rowStrideA)*portionSize );
        T* sendBuf = &buffer[0];
        T* recvBuf = &buffer[colStrideA*portionSize];

        if( A.RowRank() == A.RowAlign() )
        {
            // Pack
            // TODO: Use kernel from copy::util
            const Int AColShift = A.ColShift();
            const T* ABuf = A.LockedBuffer();
            EL_PARALLEL_FOR
            for( Int k=0; k<rowStrideA; ++k )
            {
                T* data = &recvBuf[k*portionSize];

                const Int shift = 
                  Shift_(A.ColRank()+colStrideA*k,A.ColAlign(),distSize);
                const Int offset = (shift-AColShift) / colStrideA;
                const Int thisLocalHeight = Length_(height,shift,distSize);

                for( Int iLoc=0; iLoc<thisLocalHeight; ++iLoc )
                    data[iLoc] = ABuf[offset+iLoc*rowStrideA];
            }
        }

        // (e.g., A[VC,STAR] <- A[MC,MR])
        mpi::Scatter
        ( recvBuf, portionSize,
          sendBuf, portionSize, A.RowAlign(), A.RowComm() );

        // (e.g., A[VR,STAR] <- A[VC,STAR])
        mpi::SendRecv
        ( sendBuf, portionSize, sendRankB,
          recvBuf, portionSize, recvRankB, B.DistComm() );

        // (e.g., A[MR,MC] <- A[VR,STAR])
        mpi::Gather
        ( recvBuf, portionSize,
          sendBuf, portionSize, B.RowAlign(), B.RowComm() );

        if( B.RowRank() == B.RowAlign() )
        {
            // Unpack
            // TODO: Use kernel from copy::util
            T* bufB = B.Buffer();
            EL_PARALLEL_FOR
            for( Int k=0; k<colStrideA; ++k )
            {
                const T* data = &sendBuf[k*portionSize];

                const Int shift = 
                  Shift_(B.ColRank()+rowStrideA*k,B.ColAlign(),distSize);
                const Int offset = (shift-B.ColShift()) / rowStrideA;
                const Int thisLocalHeight = Length_(height,shift,distSize);

                for( Int iLoc=0; iLoc<thisLocalHeight; ++iLoc )
                    bufB[offset+iLoc*colStrideA] = data[iLoc];
            }
        }
    }