Example #1
0
/*
 * Distributes A in such a way that
 *   Layer 0 <- A(:, 0:(n/h - 1))
 *   Layer 1 <- A(:, (n/h):(2n/h - 1))
 *     .
 *     .
 *     .
 *   Layer h-1 <- A(:, ((h-1)n/h):n)
 */
void DistributeCols
( const mpi::Comm& depthComm,
  const DistMatrix<double,MC,MR>& A, 
        DistMatrix<double,MC,MR>& B )
{
    const Grid& meshGrid = A.Grid();
    const int meshSize = meshGrid.Size();
    const int depthSize = mpi::CommSize( depthComm );
    const int depthRank = mpi::CommRank( depthComm );

    const int sendCount = A.LocalHeight()*A.LocalWidth();
    const int recvCount = sendCount / depthSize;

    // For now, we will make B as large as A...
    // TODO: NOT DO THIS
    if( A.LocalHeight() != A.LocalLDim() )
        throw std::logic_error("Local height did not match local ldim");
    B.Empty();
    B.AlignWith( A );
    Zeros( A.Height(), A.Width(), B );

    // Scatter
    const int localColOffset = (A.LocalWidth()/depthSize)*depthRank;
    mpi::Scatter
    ( A.LockedLocalBuffer(), recvCount, 
      B.LocalBuffer(0,localColOffset), recvCount, 0, depthComm );
}
Example #2
0
// Broadcast a matrix from the root grid to the others
void DepthBroadcast
( const mpi::Comm& depthComm,
  const DistMatrix<double,MC,MR>& A, 
        DistMatrix<double,MC,MR>& B )
{
    const int rank = mpi::CommRank(mpi::COMM_WORLD);
    const Grid& meshGrid = A.Grid();
    const int meshSize = meshGrid.Size();
    const int depthRank = rank / meshSize;

    const int localSize = A.LocalHeight()*A.LocalWidth();
    if( A.LocalHeight() != A.LocalLDim() )
        throw std::logic_error("Leading dimension did not match local height");

    B.Empty();
    B.AlignWith( A );
    B.ResizeTo( A.Height(), A.Width() );

    // Have the root pack the broadcast data
    if( depthRank == 0 )
        MemCopy( B.LocalBuffer(), A.LockedLocalBuffer(), localSize );

    // Broadcast from the root
    mpi::Broadcast( B.LocalBuffer(), localSize, 0, depthComm );
}
Example #3
0
void AccumulateRHS( const DistMatrix<F,VC,STAR>& X, DistMatrix<F,STAR,STAR>& Z )
{
    const Int height = X.Height();
    const Int width = X.Width();
    Z.Empty();
    Zeros( Z, height, width );

    const Int localHeight = X.LocalHeight();
    const Int colShift = X.ColShift();
    const int commSize = X.Grid().Size();
    const F* XBuffer = X.LockedBuffer();
    F* ZBuffer = Z.Buffer();
    const Int XLDim = X.LDim();
    const Int ZLDim = Z.LDim();
    for( Int iLoc=0; iLoc<localHeight; ++iLoc )
    {
        const Int i = colShift + iLoc*commSize;
        for( Int j=0; j<width; ++j )
            ZBuffer[i+j*ZLDim] = XBuffer[iLoc+j*XLDim];
    }
    mpi::AllReduce( ZBuffer, ZLDim*width, mpi::SUM, X.Grid().VCComm() );
}
Example #4
0
// Reduce across depth to get end result C
void SumContributions
( mpi::Comm& depthComm,
  const DistMatrix<double,MC,MR>& APartial,
        DistMatrix<double,MC,MR>& A )
{
    const int rank = mpi::CommRank( mpi::COMM_WORLD );
    const Grid& meshGrid = APartial.Grid();

    A.Empty();
    A.AlignWith( APartial );
    A.ResizeTo( APartial.Height(), APartial.Width() );

    if( APartial.LocalHeight() != APartial.LocalLDim() )
        throw std::logic_error
        ("APartial did not have matching local height/ldim");
    if( A.LocalHeight() != A.LocalLDim() )
        throw std::logic_error("A did not have matching local height/ldim");

    const int dataSize = APartial.LocalHeight()*APartial.LocalWidth();
    mpi::AllReduce
    ( APartial.LockedLocalBuffer(), A.LocalBuffer(), dataSize, 
      mpi::SUM, depthComm );
}