butterfly.h File Reference

Declaration of routines for butterfly-like communication scheme. More...

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Functions
int	butterfly_init (int *indices, int count, int **R, int *nR, int **S, int *nS, int **com_indices, int *com_count, int steps, MPI_Comm comm)
	Initialize tables for butterfly-like communication scheme This routine set up needed tables for the butterfly communication scheme. Sending and receiving tabs should be well allocated(at least size of number of steps in butterfly scheme). Double pointer are partially allocated, the last allocation is performed inside the routine. com_indices and com_count are also allocated inside the routine, thus they are passing by reference. They represent indices which have to be communicated an their number. Algotithm is based 2 parts. The first one identify intersection between processors indices, using 3 successives butterfly communication schemes : bottom up, top down, and top down again. The second part works locally to build sets of indices to communicate.
int	butterfly_reduce (int **R, int *nR, int nRmax, int **S, int *nS, int nSmax, double *val, int steps, MPI_Comm comm)
	Perform a sparse sum reduction (or mapped reduction) using a butterfly-like communication scheme.
double	butterfly_reduce_b (int **R, int *nR, int nRmax, int **S, int *nS, int nSmax, double *val, int b, int steps, MPI_Comm comm)

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Detailed Description

Declaration of routines for butterfly-like communication scheme.

Note:

Copyright (C) 2010 APC CNRS Université Paris Diderot 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 3 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. should have received a copy of the GNU General Public License along with this program; if not, see http://www.gnu.org/licenses/gpl.html

Author:

Pierre Cargemel

Date:

April 2012

Definition in file butterfly.h.

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Function Documentation

double butterfly_reduce_b	(	int **	R,
		int *	nR,
		int	nRmax,
		int **	S,
		int *	nS,
		int	nSmax,
		double *	val,
		int	b,
		int	steps,
		MPI_Comm	comm
	)