/* StarPU --- Runtime system for heterogeneous multicore architectures.
 *
 * Copyright (C) 2009, 2010  Université de Bordeaux 1
 * Copyright (C) 2010, 2011  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.h>
#include <common/config.h>
#include <common/htable32.h>
#include <stdint.h>
#include <string.h>

void *_starpu_htbl_search_32(struct starpu_htbl32_node *htbl, uint32_t key)
{
	unsigned currentbit;
	unsigned keysize = 32;

	struct starpu_htbl32_node *current_htbl = htbl;

	/* 000000000001111 with HTBL_NODE_SIZE 1's */
	uint32_t mask = (1<<_STARPU_HTBL32_NODE_SIZE)-1;

	for(currentbit = 0; currentbit < keysize; currentbit+=_STARPU_HTBL32_NODE_SIZE)
	{
		//	printf("search : current bit = %d \n", currentbit);
		if (STARPU_UNLIKELY(current_htbl == NULL))
			return NULL;

		/* 0000000000001111
		 *     | currentbit
		 * 0000111100000000 = offloaded_mask
		 *         |last_currentbit
		 * */

		unsigned last_currentbit =
			keysize - (currentbit + _STARPU_HTBL32_NODE_SIZE);
		uint32_t offloaded_mask = mask << last_currentbit;
		unsigned current_index =
			(key & (offloaded_mask)) >> (last_currentbit);

		current_htbl = current_htbl->children[current_index];
	}

	return current_htbl;
}

/*
 * returns the previous value of the tag, or NULL else
 */

void *_starpu_htbl_insert_32(struct starpu_htbl32_node **htbl, uint32_t key, void *entry)
{
	unsigned currentbit;
	unsigned keysize = 32;

	struct starpu_htbl32_node **current_htbl_ptr = htbl;

	/* 000000000001111 with HTBL_NODE_SIZE 1's */
	uint32_t mask = (1<<_STARPU_HTBL32_NODE_SIZE)-1;

	for(currentbit = 0; currentbit < keysize; currentbit+=_STARPU_HTBL32_NODE_SIZE)
	{
		//printf("insert : current bit = %d \n", currentbit);
		if (*current_htbl_ptr == NULL)
		{
			/* TODO pad to change that 1 into 16 ? */
			*current_htbl_ptr = (struct starpu_htbl32_node*)calloc(sizeof(struct starpu_htbl32_node), 1);
			STARPU_ASSERT(*current_htbl_ptr);
		}

		/* 0000000000001111
		 *     | currentbit
		 * 0000111100000000 = offloaded_mask
		 *         |last_currentbit
		 * */

		unsigned last_currentbit =
			keysize - (currentbit + _STARPU_HTBL32_NODE_SIZE);
		uint32_t offloaded_mask = mask << last_currentbit;
		unsigned current_index =
			(key & (offloaded_mask)) >> (last_currentbit);

		current_htbl_ptr =
			&((*current_htbl_ptr)->children[current_index]);
	}

	/* current_htbl either contains NULL or a previous entry
	 * we overwrite it anyway */
	void *old_entry = *current_htbl_ptr;
	*current_htbl_ptr = (struct starpu_htbl32_node *) entry;

	return old_entry;
}
