/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2009-2013  Université de Bordeaux 1
 * Copyright (C) 2010  Mehdi Juhoor <mjuhoor@gmail.com>
 * 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 "cholesky.h"

/*
 *	Some useful functions
 */

static struct starpu_task *create_task(starpu_tag_t id)
{
	struct starpu_task *task = starpu_task_create();
		task->cl_arg = NULL;
		task->use_tag = 1;
		task->tag_id = id;

	return task;
}

/*
 *	Create the codelets
 */

static struct starpu_codelet cl11 =
{
	.modes = { STARPU_RW },
	.cpu_funcs = {chol_cpu_codelet_update_u11, NULL},
#ifdef STARPU_USE_CUDA
	.cuda_funcs = {chol_cublas_codelet_update_u11, NULL},
#endif
	.nbuffers = 1,
	.model = &chol_model_11
};

static struct starpu_task * create_task_11(starpu_data_handle_t dataA, unsigned k, unsigned reclevel)
{
/*	FPRINTF(stdout, "task 11 k = %d TAG = %llx\n", k, (TAG11(k))); */

	struct starpu_task *task = create_task(TAG11_AUX(k, reclevel));

	task->cl = &cl11;

	/* which sub-data is manipulated ? */
	task->handles[0] = starpu_data_get_sub_data(dataA, 2, k, k);

	/* this is an important task */
	task->priority = STARPU_MAX_PRIO;

	/* enforce dependencies ... */
	if (k > 0)
	{
		starpu_tag_declare_deps(TAG11_AUX(k, reclevel), 1, TAG22_AUX(k-1, k, k, reclevel));
	}

	int n = starpu_matrix_get_nx(task->handles[0]);
	task->flops = FLOPS_SPOTRF(n);

	return task;
}

static struct starpu_codelet cl21 =
{
	.modes = { STARPU_R, STARPU_RW },
	.cpu_funcs = {chol_cpu_codelet_update_u21, NULL},
#ifdef STARPU_USE_CUDA
	.cuda_funcs = {chol_cublas_codelet_update_u21, NULL},
#endif
	.nbuffers = 2,
	.model = &chol_model_21
};

static int create_task_21(starpu_data_handle_t dataA, unsigned k, unsigned j, unsigned reclevel)
{
	int ret;

	struct starpu_task *task = create_task(TAG21_AUX(k, j, reclevel));

	task->cl = &cl21;

	/* which sub-data is manipulated ? */
	task->handles[0] = starpu_data_get_sub_data(dataA, 2, k, k);
	task->handles[1] = starpu_data_get_sub_data(dataA, 2, k, j);

	if (j == k+1)
	{
		task->priority = STARPU_MAX_PRIO;
	}

	/* enforce dependencies ... */
	if (k > 0)
	{
		starpu_tag_declare_deps(TAG21_AUX(k, j, reclevel), 2, TAG11_AUX(k, reclevel), TAG22_AUX(k-1, k, j, reclevel));
	}
	else
	{
		starpu_tag_declare_deps(TAG21_AUX(k, j, reclevel), 1, TAG11_AUX(k, reclevel));
	}

	int n = starpu_matrix_get_nx(task->handles[0]);
	task->flops = FLOPS_STRSM(n, n);

	ret = starpu_task_submit(task);
	if (ret != -ENODEV) STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_submit");
	return ret;
}

static struct starpu_codelet cl22 =
{
	.modes = { STARPU_R, STARPU_R, STARPU_RW },
	.cpu_funcs = {chol_cpu_codelet_update_u22, NULL},
#ifdef STARPU_USE_CUDA
	.cuda_funcs = {chol_cublas_codelet_update_u22, NULL},
#endif
	.nbuffers = 3,
	.model = &chol_model_22
};

static int create_task_22(starpu_data_handle_t dataA, unsigned k, unsigned i, unsigned j, unsigned reclevel)
{
	int ret;

/*	FPRINTF(stdout, "task 22 k,i,j = %d,%d,%d TAG = %llx\n", k,i,j, TAG22_AUX(k,i,j)); */

	struct starpu_task *task = create_task(TAG22_AUX(k, i, j, reclevel));

	task->cl = &cl22;

	/* which sub-data is manipulated ? */
	task->handles[0] = starpu_data_get_sub_data(dataA, 2, k, i);
	task->handles[1] = starpu_data_get_sub_data(dataA, 2, k, j);
	task->handles[2] = starpu_data_get_sub_data(dataA, 2, i, j);

	if ( (i == k + 1) && (j == k +1) )
	{
		task->priority = STARPU_MAX_PRIO;
	}

	/* enforce dependencies ... */
	if (k > 0)
	{
		starpu_tag_declare_deps(TAG22_AUX(k, i, j, reclevel), 3, TAG22_AUX(k-1, i, j, reclevel), TAG21_AUX(k, i, reclevel), TAG21_AUX(k, j, reclevel));
	}
	else
	{
		starpu_tag_declare_deps(TAG22_AUX(k, i, j, reclevel), 2, TAG21_AUX(k, i, reclevel), TAG21_AUX(k, j, reclevel));
	}

	int n = starpu_matrix_get_nx(task->handles[0]);
	task->flops = FLOPS_SGEMM(n, n, n);

	ret = starpu_task_submit(task);
	if (ret != -ENODEV) STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_submit");
	return ret;
}



/*
 *	code to bootstrap the factorization
 *	and construct the DAG
 */

static int cholesky_grain_rec(float *matA, unsigned size, unsigned ld, unsigned nblocks, unsigned nbigblocks, unsigned reclevel)
{
	int ret;

	/* create a new codelet */
	struct starpu_task *entry_task = NULL;

	/* create all the DAG nodes */
	unsigned i,j,k;

	starpu_data_handle_t dataA;

	/* monitor and partition the A matrix into blocks :
	 * one block is now determined by 2 unsigned (i,j) */
	starpu_matrix_data_register(&dataA, 0, (uintptr_t)matA, ld, size, size, sizeof(float));

	starpu_data_set_sequential_consistency_flag(dataA, 0);

	struct starpu_data_filter f =
	{
		.filter_func = starpu_matrix_filter_vertical_block,
		.nchildren = nblocks
	};

	struct starpu_data_filter f2 =
	{
		.filter_func = starpu_matrix_filter_block,
		.nchildren = nblocks
	};

	starpu_data_map_filters(dataA, 2, &f, &f2);

	for (k = 0; k < nbigblocks; k++)
	{
		struct starpu_task *task = create_task_11(dataA, k, reclevel);
		/* we defer the launch of the first task */
		if (k == 0)
		{
			entry_task = task;
		}
		else
		{
			ret = starpu_task_submit(task);
			if (ret == -ENODEV) return 77;
			STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_submit");
		}

		for (j = k+1; j<nblocks; j++)
		{
		     	ret = create_task_21(dataA, k, j, reclevel);
			if (ret == -ENODEV) return 77;

			for (i = k+1; i<nblocks; i++)
			{
				if (i <= j)
				{
				     ret = create_task_22(dataA, k, i, j, reclevel);
				     if (ret == -ENODEV) return 77;
				}
			}
		}
	}

	/* schedule the codelet */
	ret = starpu_task_submit(entry_task);
	if (STARPU_UNLIKELY(ret == -ENODEV))
	{
		FPRINTF(stderr, "No worker may execute this task\n");
		return 77;
	}

	if (nblocks == nbigblocks)
	{
		/* stall the application until the end of computations */
		starpu_tag_wait(TAG11_AUX(nblocks-1, reclevel));
		starpu_data_unpartition(dataA, 0);
		starpu_data_unregister(dataA);
		return 0;
	}
	else
	{
		STARPU_ASSERT(reclevel == 0);
		unsigned ndeps_tags = (nblocks - nbigblocks)*(nblocks - nbigblocks);

		starpu_tag_t *tag_array = malloc(ndeps_tags*sizeof(starpu_tag_t));
		STARPU_ASSERT(tag_array);

		unsigned ind = 0;
		for (i = nbigblocks; i < nblocks; i++)
		for (j = nbigblocks; j < nblocks; j++)
		{
			if (i <= j)
				tag_array[ind++] = TAG22_AUX(nbigblocks - 1, i, j, reclevel);
		}

		starpu_tag_wait_array(ind, tag_array);

		free(tag_array);

		starpu_data_unpartition(dataA, 0);
		starpu_data_unregister(dataA);

		float *newmatA = &matA[nbigblocks*(size/nblocks)*(ld+1)];

		return cholesky_grain_rec(newmatA, size/nblocks*(nblocks - nbigblocks), ld, (nblocks - nbigblocks)*2, (nblocks - nbigblocks)*2, reclevel+1);
	}
}

static void initialize_system(float **A, unsigned dim, unsigned pinned)
{
	int ret;

	ret = starpu_init(NULL);
	if (ret == -ENODEV)
		exit(77);
	STARPU_CHECK_RETURN_VALUE(ret, "starpu_init");

	starpu_cublas_init();

#ifndef STARPU_SIMGRID
	if (pinned)
	{
		starpu_malloc((void **)A, dim*dim*sizeof(float));
	}
	else
	{
		*A = malloc(dim*dim*sizeof(float));
	}
#endif
}

int cholesky_grain(float *matA, unsigned size, unsigned ld, unsigned nblocks, unsigned nbigblocks, unsigned pinned)
{
	double start;
	double end;
	int ret;

	start = starpu_timing_now();

	ret = cholesky_grain_rec(matA, size, ld, nblocks, nbigblocks, 0);

	end = starpu_timing_now();

	double timing = end - start;
	FPRINTF(stderr, "Computation took (in ms)\n");
	FPRINTF(stdout, "%2.2f\n", timing/1000);

	double flop = (1.0f*size*size*size)/3.0f;
	FPRINTF(stderr, "Synthetic GFlops : %2.2f\n", (flop/timing/1000.0f));
	return ret;
}

static void shutdown_system(float **matA, unsigned pinned)
{
	if (pinned)
	{
	     starpu_free(*matA);
	}
	else
	{
	     free(*matA);
	}

	starpu_cublas_shutdown();
	starpu_shutdown();
}

int main(int argc, char **argv)
{
	/* create a simple definite positive symetric matrix example
	 *
	 *	Hilbert matrix : h(i,j) = 1/(i+j+1)
	 * */

     	int ret;

	parse_args(argc, argv);

	float *mat = NULL;
	initialize_system(&mat, size, pinned);

#ifndef STARPU_SIMGRID
	unsigned i,j;
	for (i = 0; i < size; i++)
	{
		for (j = 0; j < size; j++)
		{
			mat[j +i*size] = (1.0f/(1.0f+i+j)) + ((i == j)?1.0f*size:0.0f);
			/* mat[j +i*size] = ((i == j)?1.0f*size:0.0f); */
		}
	}
#endif


#ifdef CHECK_OUTPUT
	FPRINTF(stdout, "Input :\n");

	for (j = 0; j < size; j++)
	{
		for (i = 0; i < size; i++)
		{
			if (i <= j)
			{
				FPRINTF(stdout, "%2.2f\t", mat[j +i*size]);
			}
			else
			{
				FPRINTF(stdout, ".\t");
			}
		}
		FPRINTF(stdout, "\n");
	}
#endif

	ret = cholesky_grain(mat, size, size, nblocks, nbigblocks, pinned);

#ifdef CHECK_OUTPUT
	FPRINTF(stdout, "Results :\n");

	for (j = 0; j < size; j++)
	{
		for (i = 0; i < size; i++)
		{
			if (i <= j)
			{
				FPRINTF(stdout, "%2.2f\t", mat[j +i*size]);
			}
			else
			{
				FPRINTF(stdout, ".\t");
				mat[j+i*size] = 0.0f; /* debug */
			}
		}
		FPRINTF(stdout, "\n");
	}

	FPRINTF(stderr, "compute explicit LLt ...\n");
	float *test_mat = malloc(size*size*sizeof(float));
	STARPU_ASSERT(test_mat);

	SSYRK("L", "N", size, size, 1.0f,
				mat, size, 0.0f, test_mat, size);

	FPRINTF(stderr, "comparing results ...\n");
	for (j = 0; j < size; j++)
	{
		for (i = 0; i < size; i++)
		{
			if (i <= j)
			{
                                FPRINTF(stdout, "%2.2f\t", test_mat[j +i*size]);
			}
			else
			{
				FPRINTF(stdout, ".\t");
			}
		}
		FPRINTF(stdout, "\n");
	}
	free(test_mat);
#endif

	shutdown_system(&mat, pinned);
	return ret;
}
