1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
/* Jazz, a program for playing chess
* Copyright (C) 2009, 2011 Evert Glebbeek
*
* 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 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef HASHTABLE_H
#define HASHTABLE_H
#include <stdint.h>
#include "move.h"
/* Types of entries that may occur in the table (flags) */
#define HASH_TYPE_EXACT 0x00000001
#define HASH_TYPE_LOWER 0x00000002
#define HASH_TYPE_UPPER 0x00000004
#ifdef __cplusplus
extern "C" {
#endif
/* Entries in the hash table */
typedef struct {
uint32_t lock; /* Store the full key (for position verification) */
move_t best_move; /* The best move returned from the previous search */
int16_t score; /* The value of this node */
int16_t depth; /* The depth to which this position was searched; distance from horizon */
uint8_t flags; /* Properties of this entry */
uint8_t generation; /* Generation of this entry */
} hash_table_entry_t;
typedef struct {
/* We keep two parallel hash tables: a "depth priority" table and an
* "always replace" table.
*/
hash_table_entry_t *data;
size_t number_of_elements;
size_t write_count;
uint8_t generation;
} hash_table_t;
hash_table_t *create_hash_table(size_t nelem);
void destroy_hash_table(hash_table_t *table);
void store_table_entry(hash_table_t *table, uint64_t key, int depth, int score, unsigned int flags, move_t best_move);
bool retrieve_table(hash_table_t *table, uint64_t key, int *depth, int *score, unsigned int *flags, move_t *best_move);
void prefetch_hashtable(hash_table_t *table, uint64_t key);
void prepare_hashtable_search(hash_table_t *table);
int count_unused_table_entries(hash_table_t *table);
#ifdef __cplusplus
}
#endif
#endif
|
