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Diffstat (limited to 'btl/libs/BLACS/scatter_impl.h')
| -rw-r--r-- | btl/libs/BLACS/scatter_impl.h | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/btl/libs/BLACS/scatter_impl.h b/btl/libs/BLACS/scatter_impl.h new file mode 100644 index 0000000..7c38c22 --- /dev/null +++ b/btl/libs/BLACS/scatter_impl.h @@ -0,0 +1,121 @@ +//===================================================== +// Copyright (C) 2011 Andrea Arteaga <andyspiros@gmail.com> +//===================================================== +// +// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. +// +#define CAT_(x,y) x##y +#define CAT(x,y) CAT_(x,y) + +#define FUNCNAME(name) CAT(CAT(TYPEPREFIX, name),_) +#define vector_t std::vector<TYPENAME> + +#include <vector> + +inline void scatter( + const int& context, // [IN] + const vector_t& GlobalMatrixVector, // [IN] Only relevant for root + vector_t& LocalMatrixVector, // [OUT] The space is reserved here + int& GlobalRows, // [IN (root) / OUT (other)] + int& GlobalCols, // [IN (root) / OUT (other)] + int& BlockRows, // [IN (root) / OUT (other)] + int& BlockCols, // [IN (root) / OUT (other)] + int& LocalRows, // [OUT] + int& LocalCols, // [OUT] + const int& rootrow = 0, // [IN] + const int& rootcol = 0 // [IN] +) { + /* Helper variables */ + int iZERO = 0, iONE = 1, iFOUR = 4; + + int myid, myrow, mycol, procrows, proccols, procnum; + blacs_pinfo_(&myid, &procnum); + blacs_gridinfo_(&context, &procrows, &proccols, &myrow, &mycol); + bool iamroot = (myrow == rootrow && mycol == rootcol); + const TYPENAME *GlobalMatrix = &GlobalMatrixVector[0]; + TYPENAME *LocalMatrix; + + /* Broadcast matrix info */ + int minfo[4]; + if (iamroot) { + minfo[0] = GlobalRows; + minfo[1] = GlobalCols; + minfo[2] = BlockRows; + minfo[3] = BlockCols; + igebs2d_(&context, "All", " ", &iFOUR, &iONE, minfo, &iFOUR); + } else { + igebr2d_(&context, "All", " ", &iFOUR, &iONE, minfo, &iFOUR, + &iZERO, &iZERO); + } + + GlobalRows = minfo[0]; + GlobalCols = minfo[1]; + BlockRows = minfo[2]; + BlockCols = minfo[3]; + + + /* Reserve space */ + LocalRows = numroc_(&GlobalRows, &BlockRows, &myrow, &iZERO, &procrows); + LocalCols = numroc_(&GlobalCols, &BlockCols, &mycol, &iZERO, &proccols); + LocalMatrixVector.resize(LocalRows*LocalCols); + LocalMatrix = &LocalMatrixVector[0]; + + /* Scatter matrix */ + int destr = 0, destc = 0; + int SendRows, SendCols; + int RecvRow = 0, RecvCol = 0; + for (int r = 0; r < GlobalRows; r += BlockRows, destr=(destr+1)%procrows) { + destc = 0; + + // Is this the last row bloc? + SendRows = BlockRows; + if (GlobalRows-r < BlockRows) + SendRows = GlobalRows-r; + if (SendRows <= 0) + SendRows = 0; + + for (int c=0; c<GlobalCols; c+=BlockCols, destc=(destc+1)%proccols) { + + // Is this the last column block? + SendCols = BlockCols; + if (GlobalCols-c < BlockCols) + SendCols = GlobalCols-c; + + // Send data + if (iamroot) { + FUNCNAME(gesd2d) (&context, &SendRows, &SendCols, + GlobalMatrix + GlobalRows*c + r, + &GlobalRows, &destr, &destc + ); + } + + // Rerceive data + if (myrow == destr && mycol == destc) { + FUNCNAME(gerv2d) (&context, &SendRows, &SendCols, + LocalMatrix+LocalRows*RecvCol+RecvRow, + &LocalRows, &rootrow, &rootcol + ); + + // Adjust the next starting column + RecvCol = (RecvCol + SendCols) % LocalCols; + } + } + + // Adjust the next starting row + if (myrow == destr) + RecvRow = (RecvRow + SendRows) % LocalRows; + + } + +} |