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Grid/lib/cartesian/Cartesian_red_black.h

322 lines
10 KiB
C++

/*************************************************************************************
Grid physics library, www.github.com/paboyle/Grid
Source file: ./lib/cartesian/Cartesian_red_black.h
Copyright (C) 2015
Author: Azusa Yamaguchi <ayamaguc@staffmail.ed.ac.uk>
Author: Peter Boyle <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_CARTESIAN_RED_BLACK_H
#define GRID_CARTESIAN_RED_BLACK_H
namespace Grid {
static const int CbRed =0;
static const int CbBlack=1;
static const int Even =CbRed;
static const int Odd =CbBlack;
// Specialise this for red black grids storing half the data like a chess board.
class GridRedBlackCartesian : public GridBase
{
public:
std::vector<int> _checker_dim_mask;
int _checker_dim;
std::vector<int> _checker_board;
virtual int CheckerBoarded(int dim){
if( dim==_checker_dim) return 1;
else return 0;
}
virtual int CheckerBoard(const std::vector<int> &site){
int linear=0;
assert(site.size()==_ndimension);
for(int d=0;d<_ndimension;d++){
if(_checker_dim_mask[d])
linear=linear+site[d];
}
return (linear&0x1);
}
// Depending on the cb of site, we toggle source cb.
// for block #b, element #e = (b, e)
// we need
virtual int CheckerBoardShiftForCB(int source_cb,int dim,int shift,int ocb){
if(dim != _checker_dim) return shift;
int fulldim =_fdimensions[dim];
shift = (shift+fulldim)%fulldim;
// Probably faster with table lookup;
// or by looping over x,y,z and multiply rather than computing checkerboard.
if ( (source_cb+ocb)&1 ) {
return (shift)/2;
} else {
return (shift+1)/2;
}
}
virtual int CheckerBoardFromOindexTable (int Oindex) {
return _checker_board[Oindex];
}
virtual int CheckerBoardFromOindex (int Oindex)
{
std::vector<int> ocoor;
oCoorFromOindex(ocoor,Oindex);
return CheckerBoard(ocoor);
}
virtual int CheckerBoardShift(int source_cb,int dim,int shift,int osite){
if(dim != _checker_dim) return shift;
int ocb=CheckerBoardFromOindex(osite);
return CheckerBoardShiftForCB(source_cb,dim,shift,ocb);
}
virtual int CheckerBoardDestination(int source_cb,int shift,int dim){
if ( _checker_dim_mask[dim] ) {
// If _fdimensions[checker_dim] is odd, then shifting by 1 in other dims
// does NOT cause a parity hop.
int add=(dim==_checker_dim) ? 0 : _fdimensions[_checker_dim];
if ( (shift+add) &0x1) {
return 1-source_cb;
} else {
return source_cb;
}
} else {
return source_cb;
}
};
////////////////////////////////////////////////////////////
// Create Redblack from original grid; require full grid pointer ?
////////////////////////////////////////////////////////////
GridRedBlackCartesian(const GridBase *base) : GridBase(base->_processors,*base)
{
int dims = base->_ndimension;
std::vector<int> checker_dim_mask(dims,1);
int checker_dim = 0;
Init(base->_fdimensions,base->_simd_layout,base->_processors,checker_dim_mask,checker_dim);
};
////////////////////////////////////////////////////////////
// Create redblack from original grid, with non-trivial checker dim mask
////////////////////////////////////////////////////////////
GridRedBlackCartesian(const GridBase *base,
const std::vector<int> &checker_dim_mask,
int checker_dim
) : GridBase(base->_processors,*base)
{
Init(base->_fdimensions,base->_simd_layout,base->_processors,checker_dim_mask,checker_dim) ;
}
virtual ~GridRedBlackCartesian() = default;
#if 0
////////////////////////////////////////////////////////////
// Create redblack grid ;; deprecate these. Should not
// need direct creation of redblack without a full grid to base on
////////////////////////////////////////////////////////////
GridRedBlackCartesian(const GridBase *base,
const std::vector<int> &dimensions,
const std::vector<int> &simd_layout,
const std::vector<int> &processor_grid,
const std::vector<int> &checker_dim_mask,
int checker_dim
) : GridBase(processor_grid,*base)
{
Init(dimensions,simd_layout,processor_grid,checker_dim_mask,checker_dim);
}
////////////////////////////////////////////////////////////
// Create redblack grid
////////////////////////////////////////////////////////////
GridRedBlackCartesian(const GridBase *base,
const std::vector<int> &dimensions,
const std::vector<int> &simd_layout,
const std::vector<int> &processor_grid) : GridBase(processor_grid,*base)
{
std::vector<int> checker_dim_mask(dimensions.size(),1);
int checker_dim = 0;
Init(dimensions,simd_layout,processor_grid,checker_dim_mask,checker_dim);
}
#endif
void Init(const std::vector<int> &dimensions,
const std::vector<int> &simd_layout,
const std::vector<int> &processor_grid,
const std::vector<int> &checker_dim_mask,
int checker_dim)
{
///////////////////////
// Grid information
///////////////////////
_checker_dim = checker_dim;
assert(checker_dim_mask[checker_dim] == 1);
_ndimension = dimensions.size();
assert(checker_dim_mask.size() == _ndimension);
assert(processor_grid.size() == _ndimension);
assert(simd_layout.size() == _ndimension);
_fdimensions.resize(_ndimension);
_gdimensions.resize(_ndimension);
_ldimensions.resize(_ndimension);
_rdimensions.resize(_ndimension);
_simd_layout.resize(_ndimension);
_lstart.resize(_ndimension);
_lend.resize(_ndimension);
_ostride.resize(_ndimension);
_istride.resize(_ndimension);
_fsites = _gsites = _osites = _isites = 1;
_checker_dim_mask = checker_dim_mask;
for (int d = 0; d < _ndimension; d++)
{
_fdimensions[d] = dimensions[d];
_gdimensions[d] = _fdimensions[d];
_fsites = _fsites * _fdimensions[d];
_gsites = _gsites * _gdimensions[d];
if (d == _checker_dim)
{
assert((_gdimensions[d] & 0x1) == 0);
_gdimensions[d] = _gdimensions[d] / 2; // Remove a checkerboard
_gsites /= 2;
}
_ldimensions[d] = _gdimensions[d] / _processors[d];
assert(_ldimensions[d] * _processors[d] == _gdimensions[d]);
_lstart[d] = _processor_coor[d] * _ldimensions[d];
_lend[d] = _processor_coor[d] * _ldimensions[d] + _ldimensions[d] - 1;
// Use a reduced simd grid
_simd_layout[d] = simd_layout[d];
_rdimensions[d] = _ldimensions[d] / _simd_layout[d]; // this is not checking if this is integer
assert(_rdimensions[d] * _simd_layout[d] == _ldimensions[d]);
assert(_rdimensions[d] > 0);
// all elements of a simd vector must have same checkerboard.
// If Ls vectorised, this must still be the case; e.g. dwf rb5d
if (_simd_layout[d] > 1)
{
if (checker_dim_mask[d])
{
assert((_rdimensions[d] & 0x1) == 0);
}
}
_osites *= _rdimensions[d];
_isites *= _simd_layout[d];
// Addressing support
if (d == 0)
{
_ostride[d] = 1;
_istride[d] = 1;
}
else
{
_ostride[d] = _ostride[d - 1] * _rdimensions[d - 1];
_istride[d] = _istride[d - 1] * _simd_layout[d - 1];
}
}
////////////////////////////////////////////////////////////////////////////////////////////
// subplane information
////////////////////////////////////////////////////////////////////////////////////////////
_slice_block.resize(_ndimension);
_slice_stride.resize(_ndimension);
_slice_nblock.resize(_ndimension);
int block = 1;
int nblock = 1;
for (int d = 0; d < _ndimension; d++)
nblock *= _rdimensions[d];
for (int d = 0; d < _ndimension; d++)
{
nblock /= _rdimensions[d];
_slice_block[d] = block;
_slice_stride[d] = _ostride[d] * _rdimensions[d];
_slice_nblock[d] = nblock;
block = block * _rdimensions[d];
}
////////////////////////////////////////////////
// Create a checkerboard lookup table
////////////////////////////////////////////////
int rvol = 1;
for (int d = 0; d < _ndimension; d++)
{
rvol = rvol * _rdimensions[d];
}
_checker_board.resize(rvol);
for (int osite = 0; osite < _osites; osite++)
{
_checker_board[osite] = CheckerBoardFromOindex(osite);
}
};
protected:
virtual int oIndex(std::vector<int> &coor)
{
int idx = 0;
for (int d = 0; d < _ndimension; d++)
{
if (d == _checker_dim)
{
idx += _ostride[d] * ((coor[d] / 2) % _rdimensions[d]);
}
else
{
idx += _ostride[d] * (coor[d] % _rdimensions[d]);
}
}
return idx;
};
virtual int iIndex(std::vector<int> &lcoor)
{
int idx = 0;
for (int d = 0; d < _ndimension; d++)
{
if (d == _checker_dim)
{
idx += _istride[d] * (lcoor[d] / (2 * _rdimensions[d]));
}
else
{
idx += _istride[d] * (lcoor[d] / _rdimensions[d]);
}
}
return idx;
}
};
}
#endif