commit 3ca8bda95f268b5177b3a0c22bf7bbcd21df775c
parent 317a3513ae4fca24f5ab9d34b38e198c396b5774
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date: Mon, 7 Aug 2023 12:31:05 +0200
Initialize Zobrist keys and generate hash
Diffstat:
8 files changed, 94 insertions(+), 6 deletions(-)
diff --git a/src/attacks/magic_generate.c b/src/attacks/magic_generate.c
@@ -10,8 +10,7 @@
const char *FORMAT = "C64(0x%llx),\n";
U64 generate_magic_number() {
- return random_get_U64() & random_get_U64() &
- random_get_U64();
+ return random_get_U64() & random_get_U64() & random_get_U64();
}
U64 find_magic_number(Square square, int relevant_bits, int bishop) {
diff --git a/src/board/CMakeLists.txt b/src/board/CMakeLists.txt
@@ -1,5 +1,6 @@
add_library(board OBJECT
board.c
+ zobrist.c
)
target_include_directories(board
diff --git a/src/board/board.c b/src/board/board.c
@@ -6,6 +6,7 @@
#include <cul/mem.h>
#include "board.h"
+#include "zobrist.h"
Board *board_new(void) {
Board *p;
@@ -22,6 +23,8 @@ eCastle board_castle(const Board *self) { return self->castle; }
eColor board_side(const Board *self) { return self->side; }
U64 board_color(const Board *self, eColor color) { return self->color[color]; }
U64 board_piece(const Board *self, ePiece piece) { return self->piece[piece]; }
+U64 board_hash(const Board *self) { return self->hash; }
+
U64 board_occupancy(const Board *self) {
return self->color[WHITE] | self->color[BLACK];
}
@@ -177,6 +180,7 @@ Board *board_from_FEN(Board *board, const char *fen) {
board->enpassant = coordinates_to_square(fen);
}
+ board->hash = zobrist_hash(board);
return board;
}
@@ -213,5 +217,6 @@ void board_print(const Board *self) {
printf(" Castling: %c%c%c%c\n", (self->castle & WK) ? 'K' : '-',
(self->castle & WQ) ? 'Q' : '-', (self->castle & BK) ? 'k' : '-',
(self->castle & BQ) ? 'q' : '-');
+ printf(" Hash: %llu\n", self->hash);
printf("\n");
}
diff --git a/src/board/zobrist.c b/src/board/zobrist.c
@@ -0,0 +1,66 @@
+#include "zobrist.h"
+#include "board.h"
+#include "piece.h"
+#include "random.h"
+#include "utils.h"
+
+U64 castle_keys[16];
+U64 enpassant_keys[64];
+U64 piece_keys[16][64];
+U64 side_key;
+
+void init_hash_keys() {
+ random_state_reset();
+
+ for (int piece = PAWN; piece <= KING; piece++) {
+ int piece_index_white = piece_index(piece_get(piece, WHITE));
+ int piece_index_black = piece_index(piece_get(piece, BLACK));
+ for (int square = 0; square < 64; square++) {
+ piece_keys[piece_index_white][square] = random_get_U64();
+ piece_keys[piece_index_black][square] = random_get_U64();
+ }
+ }
+
+ for (int square = 0; square < 64; square++) {
+ enpassant_keys[square] = random_get_U64();
+ }
+
+ for (int castle = 0; castle < 16; castle++) {
+ castle_keys[castle] = random_get_U64();
+ }
+
+ side_key = random_get_U64();
+}
+
+void zobrist_init(void) { init_hash_keys(); }
+
+U64 zobrist_hash(const Board *board) {
+ U64 key_final = C64(0);
+ Square square;
+
+ for (int piece = PAWN; piece <= KING; piece++) {
+ Piece piece_white = piece_get(piece, WHITE);
+ U64 bitboard_white = board_pieceSet(board, piece_white);
+ int piece_white_index = piece_index(piece_white);
+
+ bitboard_for_each_bit(square, bitboard_white) {
+ key_final ^= piece_keys[piece_white_index][square];
+ }
+
+ Piece piece_black = piece_get(piece, BLACK);
+ U64 bitboard_black = board_pieceSet(board, piece_black);
+ int piece_black_index = piece_index(piece_black);
+
+ bitboard_for_each_bit(square, bitboard_black) {
+ key_final ^= piece_keys[piece_black_index][square];
+ }
+ }
+
+ key_final ^= castle_keys[board_castle(board)];
+
+ if (board_side(board)) key_final ^= side_key;
+ if (board_enpassant(board) != no_sq)
+ key_final ^= enpassant_keys[board_enpassant(board)];
+
+ return key_final;
+}
diff --git a/src/engine/CMakeLists.txt b/src/engine/CMakeLists.txt
@@ -7,6 +7,7 @@ target_link_libraries(engine
PRIVATE piece
PRIVATE score
PRIVATE utils
+ PRIVATE random
)
target_link_libraries(engine PRIVATE "cul")
diff --git a/src/engine/engine.c b/src/engine/engine.c
@@ -9,6 +9,7 @@
#include "perft.h"
#include "score.h"
#include "utils.h"
+#include "zobrist.h"
#include <cul/assert.h>
#include <cul/mem.h>
@@ -455,7 +456,7 @@ Board *Instruction_parse(Instruction *self, Board *board) {
}
void uci_loop(void) {
- Board *board = NULL;
+ Board board;
Instruction *instruction;
char input[200000];
@@ -469,18 +470,22 @@ void uci_loop(void) {
if (!fgets(input, sizeof(input), stdin)) continue;
instruction = Instruction_new(input);
- if (!(board = Instruction_parse(instruction, board))) break;
+ if (!Instruction_parse(instruction, &board)) break;
Instruction_free(&instruction);
}
Instruction_free(&instruction);
- board_free(&board);
}
/* MAIN */
-int main(void) {
+void init(void) {
attacks_init();
+ zobrist_init();
+}
+
+int main(void) {
+ init();
uci_loop();
return 0;
}
diff --git a/src/include/board.h b/src/include/board.h
@@ -15,6 +15,7 @@ typedef struct Board Board;
struct Board {
U64 color[2];
U64 piece[6];
+ U64 hash;
eColor side;
Square enpassant;
eCastle castle;
@@ -30,6 +31,7 @@ U64 board_piece(const Board *self, ePiece piece);
eCastle board_castle(const Board *self);
eColor board_side(const Board *self);
Square board_enpassant(const Board *self);
+U64 board_hash(const Board *self);
void board_enpassant_set(Board *self, Square target);
diff --git a/src/include/zobrist.h b/src/include/zobrist.h
@@ -0,0 +1,9 @@
+#ifndef STELLAR_ZOBRIST_H
+#define STELLAR_ZOBRIST_H
+
+#include "board.h"
+
+void zobrist_init(void);
+U64 zobrist_hash(const Board *board);
+
+#endif
