Josh
c02ec7875d
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Python tests (make) / test (push) Successful in 10s
Reviewed-on: #5 Co-authored-by: Josh <josh@joshuaschuett.com> Co-committed-by: Josh <josh@joshuaschuett.com>
103 lines
2.6 KiB
C
103 lines
2.6 KiB
C
#include "bitboard.h"
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#include <stdio.h>
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uint64_t PAWN_ATTACKS[2][64];
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uint64_t KNIGHT_ATTACKS[64];
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uint64_t KING_ATTACKS[64];
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void create_knight_attack_cache(void) {
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for (int sq = 0; sq < 64; sq++) {
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uint64_t b = 1ULL << sq;
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uint64_t mask = 0ULL;
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mask |= (b & ~FILE_A) << 15;
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mask |= (b & ~FILE_H) << 17;
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mask |= (b & ~(FILE_A | FILE_B)) << 6;
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mask |= (b & ~(FILE_G | FILE_H)) << 10;
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mask |= (b & ~FILE_A) >> 17;
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mask |= (b & ~FILE_H) >> 15;
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mask |= (b & ~(FILE_A | FILE_B)) >> 10;
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mask |= (b & ~(FILE_G | FILE_H)) >> 6;
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KNIGHT_ATTACKS[sq] = mask;
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}
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}
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void create_pawn_attack_cache(void) {
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for (int sq = 0; sq < 64; sq++) {
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uint64_t b = 1ULL << sq;
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// White: NE (+9), NW (+7), but never from rank 8
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uint64_t w = ((b & ~FILE_H & ~RANK_8) << 9) | ((b & ~FILE_A & ~RANK_8) << 7);
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// Black: SE (-7), SW (-9), but never from rank 1
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uint64_t bl = ((b & ~FILE_H & ~RANK_1) >> 7) | ((b & ~FILE_A & ~RANK_1) >> 9);
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PAWN_ATTACKS[WHITE][sq] = w;
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PAWN_ATTACKS[BLACK][sq] = bl;
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}
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}
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void create_king_attack_cache(void) {
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for (int sq = 0; sq < 64; sq++) {
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uint64_t b = 1ULL << sq;
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uint64_t mask = 0ULL;
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// North / South
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mask |= (b & ~RANK_8) << 8;
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mask |= (b & ~RANK_1) >> 8;
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// East / West
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mask |= (b & ~FILE_H) << 1;
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mask |= (b & ~FILE_A) >> 1;
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// Diagonals
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mask |= (b & ~FILE_A & ~RANK_8) << 7;
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mask |= (b & ~FILE_H & ~RANK_8) << 9;
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mask |= (b & ~FILE_A & ~RANK_1) >> 9;
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mask |= (b & ~FILE_H & ~RANK_1) >> 7;
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KING_ATTACKS[sq] = mask;
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}
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}
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static int first_set_index(uint64_t bb) {
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for (int i = 0; i < 64; ++i) {
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if ((bb >> i) & 1ULL) return i;
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}
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return -1;
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}
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static int pop_lsb_index(uint64_t *bb) {
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if (*bb == 0) return -1;
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int idx = first_set_index(*bb);
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// Clears bit.
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*bb &= ~(1ULL << idx);
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return idx;
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}
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void print_board(const struct Board *b) {
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static const char PIECE_CH[12] = {
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'P','N','B','R','Q','K',
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'p','n','b','r','q','k'
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};
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char grid[64];
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for (int i = 0; i < 64; ++i) grid[i] = '.';
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for (int p = 0; p < 12; ++p) {
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uint64_t bb = b->pieces[p];
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while (bb) {
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int sq = pop_lsb_index(&bb);
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grid[sq] = PIECE_CH[p];
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}
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}
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for (int r = 7; r >= 0; --r) {
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for (int f = 0; f < 8; ++f) {
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putchar(grid[r * 8 + f]);
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if (f < 7) putchar(' ');
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}
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putchar('\n');
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}
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} |