/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/cshift/Cshift_mpi.h
Copyright (C) 2015
Author: Peter Boyle <paboyle@ph.ed.ac.uk>
Author: paboyle <paboyle@ph.ed.ac.uk>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
See the full license in the file "LICENSE" in the top level distribution directory
*************************************************************************************/
/* END LEGAL */
#ifndef _GRID_CSHIFT_MPI_H_
#define _GRID_CSHIFT_MPI_H_
namespace Grid {
template<class vobj> Lattice<vobj> Cshift(const Lattice<vobj> &rhs,int dimension,int shift)
{
typedef typename vobj::vector_type vector_type;
typedef typename vobj::scalar_type scalar_type;
Lattice<vobj> ret(rhs._grid);
int fd = rhs._grid->_fdimensions[dimension];
int rd = rhs._grid->_rdimensions[dimension];
// Map to always positive shift modulo global full dimension.
shift = (shift+fd)%fd;
ret.checkerboard = rhs._grid->CheckerBoardDestination(rhs.checkerboard,shift,dimension);
// the permute type
int simd_layout = rhs._grid->_simd_layout[dimension];
int comm_dim = rhs._grid->_processors[dimension] >1 ;
int splice_dim = rhs._grid->_simd_layout[dimension]>1 && (comm_dim);
if ( !comm_dim ) {
// std::cout << "Cshift_local" <<std::endl;
Cshift_local(ret,rhs,dimension,shift); // Handles checkerboarding
} else if ( splice_dim ) {
// std::cout << "Cshift_comms_simd" <<std::endl;
Cshift_comms_simd(ret,rhs,dimension,shift);
} else {
// std::cout << "Cshift_comms" <<std::endl;
Cshift_comms(ret,rhs,dimension,shift);
}
return ret;
}
template<class vobj> void Cshift_comms(Lattice<vobj>& ret,const Lattice<vobj> &rhs,int dimension,int shift)
{
int sshift[2];
sshift[0] = rhs._grid->CheckerBoardShiftForCB(rhs.checkerboard,dimension,shift,Even);
sshift[1] = rhs._grid->CheckerBoardShiftForCB(rhs.checkerboard,dimension,shift,Odd);
// std::cout << "Cshift_comms dim "<<dimension<<"cb "<<rhs.checkerboard<<"shift "<<shift<<" sshift " << sshift[0]<<" "<<sshift[1]<<std::endl;
if ( sshift[0] == sshift[1] ) {
// std::cout << "Single pass Cshift_comms" <<std::endl;
Cshift_comms(ret,rhs,dimension,shift,0x3);
} else {
// std::cout << "Two pass Cshift_comms" <<std::endl;
Cshift_comms(ret,rhs,dimension,shift,0x1);// if checkerboard is unfavourable take two passes
Cshift_comms(ret,rhs,dimension,shift,0x2);// both with block stride loop iteration
}
}
template<class vobj> void Cshift_comms_simd(Lattice<vobj>& ret,const Lattice<vobj> &rhs,int dimension,int shift)
{
int sshift[2];
sshift[0] = rhs._grid->CheckerBoardShiftForCB(rhs.checkerboard,dimension,shift,Even);
sshift[1] = rhs._grid->CheckerBoardShiftForCB(rhs.checkerboard,dimension,shift,Odd);
if ( sshift[0] == sshift[1] ) {
Cshift_comms_simd(ret,rhs,dimension,shift,0x3);
} else {
Cshift_comms_simd(ret,rhs,dimension,shift,0x1);// if checkerboard is unfavourable take two passes
Cshift_comms_simd(ret,rhs,dimension,shift,0x2);// both with block stride loop iteration
}
}
template<class vobj> void Cshift_comms(Lattice<vobj> &ret,const Lattice<vobj> &rhs,int dimension,int shift,int cbmask)
{
typedef typename vobj::vector_type vector_type;
typedef typename vobj::scalar_type scalar_type;
GridBase *grid=rhs._grid;
Lattice<vobj> temp(rhs._grid);
int fd = rhs._grid->_fdimensions[dimension];
int rd = rhs._grid->_rdimensions[dimension];
int pd = rhs._grid->_processors[dimension];
int simd_layout = rhs._grid->_simd_layout[dimension];
int comm_dim = rhs._grid->_processors[dimension] >1 ;
assert(simd_layout==1);
assert(comm_dim==1);
assert(shift>=0);
assert(shift<fd);
int buffer_size = rhs._grid->_slice_nblock[dimension]*rhs._grid->_slice_block[dimension];
commVector<vobj> send_buf(buffer_size);
commVector<vobj> recv_buf(buffer_size);
int cb= (cbmask==0x2)? Odd : Even;
int sshift= rhs._grid->CheckerBoardShiftForCB(rhs.checkerboard,dimension,shift,cb);
for(int x=0;x<rd;x++){
int sx = (x+sshift)%rd;
int comm_proc = ((x+sshift)/rd)%pd;
if (comm_proc==0) {
Copy_plane(ret,rhs,dimension,x,sx,cbmask);
} else {
int words = send_buf.size();
if (cbmask != 0x3) words=words>>1;
int bytes = words * sizeof(vobj);
Gather_plane_simple (rhs,send_buf,dimension,sx,cbmask);
int rank = grid->_processor;
int recv_from_rank;
int xmit_to_rank;
grid->ShiftedRanks(dimension,comm_proc,xmit_to_rank,recv_from_rank);
grid->SendToRecvFrom((void *)&send_buf[0],
xmit_to_rank,
(void *)&recv_buf[0],
recv_from_rank,
bytes);
// for(int i=0;i<words;i++){
// std::cout << "SendRecv ["<<i<<"] snd "<<send_buf[i]<<" rcv " << recv_buf[i] << " 0x" << cbmask<<std::endl;
// }
Scatter_plane_simple (ret,recv_buf,dimension,x,cbmask);
}
}
}
template<class vobj> void Cshift_comms_simd(Lattice<vobj> &ret,const Lattice<vobj> &rhs,int dimension,int shift,int cbmask)
{
GridBase *grid=rhs._grid;
const int Nsimd = grid->Nsimd();
typedef typename vobj::vector_type vector_type;
typedef typename vobj::scalar_object scalar_object;
typedef typename vobj::scalar_type scalar_type;
int fd = grid->_fdimensions[dimension];
int rd = grid->_rdimensions[dimension];
int ld = grid->_ldimensions[dimension];
int pd = grid->_processors[dimension];
int simd_layout = grid->_simd_layout[dimension];
int comm_dim = grid->_processors[dimension] >1 ;
assert(comm_dim==1);
assert(simd_layout==2);
assert(shift>=0);
assert(shift<fd);
int permute_type=grid->PermuteType(dimension);
///////////////////////////////////////////////
// Simd direction uses an extract/merge pair
///////////////////////////////////////////////
int buffer_size = grid->_slice_nblock[dimension]*grid->_slice_block[dimension];
int words = sizeof(vobj)/sizeof(vector_type);
std::vector<commVector<scalar_object> > send_buf_extract(Nsimd,commVector<scalar_object>(buffer_size) );
std::vector<commVector<scalar_object> > recv_buf_extract(Nsimd,commVector<scalar_object>(buffer_size) );
int bytes = buffer_size*sizeof(scalar_object);
std::vector<scalar_object *> pointers(Nsimd); //
std::vector<scalar_object *> rpointers(Nsimd); // received pointers
///////////////////////////////////////////
// Work out what to send where
///////////////////////////////////////////
int cb = (cbmask==0x2)? Odd : Even;
int sshift= grid->CheckerBoardShiftForCB(rhs.checkerboard,dimension,shift,cb);
// loop over outer coord planes orthog to dim
for(int x=0;x<rd;x++){
// FIXME call local permute copy if none are offnode.
for(int i=0;i<Nsimd;i++){
pointers[i] = &send_buf_extract[i][0];
}
int sx = (x+sshift)%rd;
Gather_plane_extract(rhs,pointers,dimension,sx,cbmask);
for(int i=0;i<Nsimd;i++){
int inner_bit = (Nsimd>>(permute_type+1));
int ic= (i&inner_bit)? 1:0;
int my_coor = rd*ic + x;
int nbr_coor = my_coor+sshift;
int nbr_proc = ((nbr_coor)/ld) % pd;// relative shift in processors
int nbr_ic = (nbr_coor%ld)/rd; // inner coord of peer
int nbr_ox = (nbr_coor%rd); // outer coord of peer
int nbr_lane = (i&(~inner_bit));
int recv_from_rank;
int xmit_to_rank;
if (nbr_ic) nbr_lane|=inner_bit;
assert (sx == nbr_ox);
if(nbr_proc){
grid->ShiftedRanks(dimension,nbr_proc,xmit_to_rank,recv_from_rank);
grid->SendToRecvFrom((void *)&send_buf_extract[nbr_lane][0],
xmit_to_rank,
(void *)&recv_buf_extract[i][0],
recv_from_rank,
bytes);
rpointers[i] = &recv_buf_extract[i][0];
} else {
rpointers[i] = &send_buf_extract[nbr_lane][0];
}
}
Scatter_plane_merge(ret,rpointers,dimension,x,cbmask);
}
}
}
#endif