starpu-max/mpi/starpu_mpi_datatype.c

/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2009-2011  Université de Bordeaux 1
 * Copyright (C) 2010, 2011, 2012  Centre National de la Recherche Scientifique
 *
 * StarPU is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at
 * your option) any later version.
 *
 * StarPU 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 Lesser General Public License in COPYING.LGPL for more details.
 */

#include <starpu_mpi_datatype.h>

typedef int (*handle_to_datatype_func)(starpu_data_handle_t, MPI_Datatype *);

/*
 * 	Matrix
 */

static int handle_to_datatype_matrix(starpu_data_handle_t data_handle, MPI_Datatype *datatype)
{
	int ret;

	unsigned nx = starpu_matrix_get_nx(data_handle);
	unsigned ny = starpu_matrix_get_ny(data_handle);
	unsigned ld = starpu_matrix_get_local_ld(data_handle);
	size_t elemsize = starpu_matrix_get_elemsize(data_handle);

	ret = MPI_Type_vector(ny, nx*elemsize, ld*elemsize, MPI_BYTE, datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	ret = MPI_Type_commit(datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	return 0;
}

/*
 * 	Block
 */

static int handle_to_datatype_block(starpu_data_handle_t data_handle, MPI_Datatype *datatype)
{
	int ret;

	unsigned nx = starpu_block_get_nx(data_handle);
	unsigned ny = starpu_block_get_ny(data_handle);
	unsigned nz = starpu_block_get_nz(data_handle);
	unsigned ldy = starpu_block_get_local_ldy(data_handle);
	unsigned ldz = starpu_block_get_local_ldz(data_handle);
	size_t elemsize = starpu_block_get_elemsize(data_handle);

	MPI_Datatype datatype_2dlayer;
	ret = MPI_Type_vector(ny, nx*elemsize, ldy*elemsize, MPI_BYTE, &datatype_2dlayer);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	ret = MPI_Type_commit(&datatype_2dlayer);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	ret = MPI_Type_hvector(nz, 1, ldz*elemsize, datatype_2dlayer, datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	ret = MPI_Type_commit(datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	return 0;
}

/*
 * 	Vector
 */

static int handle_to_datatype_vector(starpu_data_handle_t data_handle, MPI_Datatype *datatype)
{
	int ret;

	unsigned nx = starpu_vector_get_nx(data_handle);
	size_t elemsize = starpu_vector_get_elemsize(data_handle);

	ret = MPI_Type_contiguous(nx*elemsize, MPI_BYTE, datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	ret = MPI_Type_commit(datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	return 0;
}

/*
 * 	Variable
 */

static int handle_to_datatype_variable(starpu_data_handle_t data_handle, MPI_Datatype *datatype)
{
	int ret;

	size_t elemsize = starpu_variable_get_elemsize(data_handle);

	ret = MPI_Type_contiguous(elemsize, MPI_BYTE, datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	ret = MPI_Type_commit(datatype);
	STARPU_ASSERT(ret == MPI_SUCCESS);

	return 0;
}

/*
 *	Generic
 */

static handle_to_datatype_func handle_to_datatype_funcs[STARPU_MAX_INTERFACE_ID] =
{
	[STARPU_MATRIX_INTERFACE_ID]	= handle_to_datatype_matrix,
	[STARPU_BLOCK_INTERFACE_ID]	= handle_to_datatype_block,
	[STARPU_VECTOR_INTERFACE_ID]	= handle_to_datatype_vector,
	[STARPU_CSR_INTERFACE_ID]	= NULL,
	[STARPU_BCSR_INTERFACE_ID]	= NULL,
	[STARPU_VARIABLE_INTERFACE_ID]	= handle_to_datatype_variable,
	[STARPU_VOID_INTERFACE_ID]      = NULL,
	[STARPU_MULTIFORMAT_INTERFACE_ID] = NULL,
};

int starpu_mpi_handle_to_datatype(starpu_data_handle_t data_handle, MPI_Datatype *datatype, int *count)
{
	enum starpu_data_interface_id id = starpu_handle_get_interface_id(data_handle);

	if (id <= STARPU_MULTIFORMAT_INTERFACE_ID)
	{
		handle_to_datatype_func func = handle_to_datatype_funcs[id];
		STARPU_ASSERT(func);
		func(data_handle, datatype);
		*count = 1;
		return 0;
	}
	else
	{
		/* The datatype is not predefined by StarPU */
		*count = starpu_handle_get_size(data_handle);
		*datatype = MPI_BYTE;
		return 1;
	}
	return 0;
}