void AllGather
( const DistMatrix<T, U, V >& A,
DistMatrix<T,Collect<U>(),Collect<V>()>& B )
{
EL_DEBUG_CSE
AssertSameGrids( A, B );
const Int height = A.Height();
const Int width = A.Width();
B.SetGrid( A.Grid() );
B.Resize( height, width );
if( A.Participating() )
{
if( A.DistSize() == 1 )
{
Copy( A.LockedMatrix(), B.Matrix() );
}
else
{
const Int colStride = A.ColStride();
const Int rowStride = A.RowStride();
const Int distStride = colStride*rowStride;
const Int maxLocalHeight = MaxLength(height,colStride);
const Int maxLocalWidth = MaxLength(width,rowStride);
const Int portionSize = mpi::Pad( maxLocalHeight*maxLocalWidth );
vector<T> buf;
FastResize( buf, (distStride+1)*portionSize );
T* sendBuf = &buf[0];
T* recvBuf = &buf[portionSize];
// Pack
util::InterleaveMatrix
( A.LocalHeight(), A.LocalWidth(),
A.LockedBuffer(), 1, A.LDim(),
sendBuf, 1, A.LocalHeight() );
// Communicate
mpi::AllGather
( sendBuf, portionSize, recvBuf, portionSize, A.DistComm() );
// Unpack
util::StridedUnpack
( height, width,
A.ColAlign(), colStride,
A.RowAlign(), rowStride,
recvBuf, portionSize,
B.Buffer(), B.LDim() );
}
}
if( A.Grid().InGrid() && A.CrossComm() != mpi::COMM_SELF )
El::Broadcast( B, A.CrossComm(), A.Root() );
}
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];
}
}
}