/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\ * This is GNU Go, a Go program. Contact gnugo@gnu.org, or see * * http://www.gnu.org/software/gnugo/ for more information. * * * * Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, * * 2008 and 2009 by the Free Software Foundation. * * * * 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 - version 3 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 in file COPYING for more details. * * * * You should have received a copy of the GNU General Public * * License along with this program; if not, write to the Free * * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * * Boston, MA 02111, USA. * \* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ #include "board.h" #include "hash.h" #include "random.h" #include #include #include /* * This file, together with engine/hash.h implements hashing of go positions * using a method known as Zobrist hashing. See the Texinfo documentation * (Reading/Hashing) for more information. */ /* ================================================================ */ /* Random values for the board hash function. For stones and ko position. */ static Hash_data white_hash[BOARDMAX]; static Hash_data black_hash[BOARDMAX]; static Hash_data ko_hash[BOARDMAX]; static Hash_data komaster_hash[NUM_KOMASTER_STATES]; static Hash_data kom_pos_hash[BOARDMAX]; static Hash_data goal_hash[BOARDMAX]; /* Get a random Hashvalue, where all bits are used. */ static Hashvalue hash_rand(void) { int i; Hashvalue h = 0; for (i = 0; 32*i < (int) (CHAR_BIT*sizeof(Hashvalue)); i++) h |= (Hashvalue) gg_urand() << 32*i; return h; } /* Fill an array with random numbers for Zobrist hashing. */ void hash_init_zobrist_array(Hash_data *array, int size) { int i, j; for (i = 0; i < size; i++) for (j = 0; j < NUM_HASHVALUES; j++) array[i].hashval[j] = hash_rand(); } /* * Initialize the board hash system. */ void hash_init(void) { static int is_initialized = 0; if (is_initialized) return; INIT_ZOBRIST_ARRAY(black_hash); INIT_ZOBRIST_ARRAY(white_hash); INIT_ZOBRIST_ARRAY(ko_hash); INIT_ZOBRIST_ARRAY(komaster_hash); INIT_ZOBRIST_ARRAY(kom_pos_hash); INIT_ZOBRIST_ARRAY(goal_hash); is_initialized = 1; } /* ---------------------------------------------------------------- */ /* Calculate the hashvalue from scratch. */ void hashdata_recalc(Hash_data *hd, Intersection *p, int ko_pos) { int pos; hashdata_clear(hd); for (pos = BOARDMIN; pos < BOARDMAX; pos++) { if (p[pos] == WHITE) hashdata_xor(*hd, white_hash[pos]); else if (p[pos] == BLACK) hashdata_xor(*hd, black_hash[pos]); } if (ko_pos != 0) hashdata_xor(*hd, ko_hash[ko_pos]); } /* Clear hashdata. */ void hashdata_clear(Hash_data *hd) { int i; for (i = 0; i < NUM_HASHVALUES; i++) hd->hashval[i] = 0; } /* Set or remove ko in the hash value and hash position. */ void hashdata_invert_ko(Hash_data *hd, int pos) { hashdata_xor(*hd, ko_hash[pos]); } /* Set or remove a stone of COLOR at pos in a Hash_data. */ void hashdata_invert_stone(Hash_data *hd, int pos, int color) { if (color == BLACK) hashdata_xor(*hd, black_hash[pos]); else if (color == WHITE) hashdata_xor(*hd, white_hash[pos]); } /* Set or remove the komaster value in the hash data. */ void hashdata_invert_komaster(Hash_data *hd, int komaster) { hashdata_xor(*hd, komaster_hash[komaster]); } /* Set or remove the komaster position in the hash data. */ void hashdata_invert_kom_pos(Hash_data *hd, int kom_pos) { hashdata_xor(*hd, kom_pos_hash[kom_pos]); } /* Calculate a transformation invariant hashvalue. */ void hashdata_calc_orientation_invariant(Hash_data *hd, Intersection *p, int ko_pos) { int pos; int rot; Hash_data hd_rot; for (rot = 0; rot < 8; rot++) { hashdata_clear(&hd_rot); for (pos = BOARDMIN; pos < BOARDMAX; pos++) { if (p[pos] == WHITE) hashdata_xor(hd_rot, white_hash[rotate1(pos, rot)]); else if (p[pos] == BLACK) hashdata_xor(hd_rot, black_hash[rotate1(pos, rot)]); } if (ko_pos != NO_MOVE) hashdata_xor(hd_rot, ko_hash[rotate1(ko_pos, rot)]); if (rot == 0 || hashdata_is_smaller(hd_rot, *hd)) *hd = hd_rot; } } /* Compute hash value to identify the goal area. */ Hash_data goal_to_hashvalue(const signed char *goal) { int pos; Hash_data return_value; hashdata_clear(&return_value); for (pos = BOARDMIN; pos < BOARDMAX; pos++) if (ON_BOARD(pos) && goal[pos]) hashdata_xor(return_value, goal_hash[pos]); return return_value; } #define HASHVALUE_NUM_DIGITS (1 + (CHAR_BIT * SIZEOF_HASHVALUE - 1) / 4) #define BUFFER_SIZE (1 + NUM_HASHVALUES * HASHVALUE_NUM_DIGITS) char * hashdata_to_string(Hash_data *hashdata) { static char buffer[BUFFER_SIZE]; int n = 0; int k; /* Loop backwards for consistency between 32 and 64 bit platforms. */ for (k = NUM_HASHVALUES - 1; k >= 0; k--) { n += sprintf(buffer + n, HASHVALUE_PRINT_FORMAT, HASHVALUE_NUM_DIGITS, hashdata->hashval[k]); gg_assert(n < BUFFER_SIZE); } return buffer; } #if NUM_HASHVALUES > 2 int hashdata_is_equal_func(Hash_data *hd1, Hash_data *hd2) { int i; for (i = 0; i < NUM_HASHVALUES; i++) if (hd1->hashval[i] != hd2->hashval[i]) return 0; return 1; } int hashdata_is_smaller_func(Hash_data *hd1, Hash_data *hd2) { int i; for (i = 0; i < NUM_HASHVALUES; i++) if (hd1->hashval[i] < hd2->hashval[i]) return 1; else if (hd1->hashval[i] > hd2->hashval[i]) return 0; return 0; } #endif /* * Local Variables: * tab-width: 8 * c-basic-offset: 2 * End: */