797 lines
23 KiB
C
797 lines
23 KiB
C
#pragma once
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#include <locale.h>
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#include <stdint.h>
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#include <assert.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <inttypes.h>
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/* BIT MANIPULATION
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* ================ */
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static inline uint64_t popcount(uint64_t n)
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{
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// TODO: check of popcountll support
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return (uint64_t)__builtin_popcountll(n);
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}
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static inline uint64_t ctz(uint64_t n)
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{
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assert(n != 0);
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return __builtin_ctzll(n);
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}
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/* BITBOARD AND INDEX DATATYPES AND HELPERS
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* ========================================= */
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typedef uint64_t bitboard;
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#define BITBOARD( \
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a8,b8,c8,d8,e8,f8,g8,h8, \
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a7,b7,c7,d7,e7,f7,g7,h7, \
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a6,b6,c6,d6,e6,f6,g6,h6, \
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a5,b5,c5,d5,e5,f5,g5,h5, \
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a4,b4,c4,d4,e4,f4,g4,h4, \
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a3,b3,c3,d3,e3,f3,g3,h3, \
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a2,b2,c2,d2,e2,f2,g2,h2, \
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a1,b1,c1,d1,e1,f1,g1,h1) \
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(bitboard)\
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0b##\
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h8##g8##f8##e8##d8##c8##b8##a8##\
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h7##g7##f7##e7##d7##c7##b7##a7##\
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h6##g6##f6##e6##d6##c6##b6##a6##\
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h5##g5##f5##e5##d5##c5##b5##a5##\
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h4##g4##f4##e4##d4##c4##b4##a4##\
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h3##g3##f3##e3##d3##c3##b3##a3##\
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h2##g2##f2##e2##d2##c2##b2##a2##\
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h1##g1##f1##e1##d1##c1##b1##a1##\
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ULL
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#define BITBOARD_FMT PRIu64
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#define BITBOARD_FMT_X PRIx64
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typedef uint64_t index;
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#define INDEX(n) n##ULL
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#define INDEX_FMT PRIu64
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#define RANK_SHIFT_UP(b, n) ((b) << (index)(n)*8ULL)
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#define RANK_SHIFT_DOWN(b, n) ((b) >> (index)(n)*8ULL)
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#define FILE_SHIFT_LEFT(b, n) ((b) >> (index)(n)*1ULL)
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#define FILE_SHIFT_RIGHT(b, n) ((b) << (index)(n)*1ULL)
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#define FILE_MASK(n) FILE_SHIFT_RIGHT((index)0x0101010101010101ULL, n)
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#define RANK_MASK(n) RANK_SHIFT_UP((index)0x00000000000000FFULL, n)
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#define INDEX_FROM_RF(rank, file) ((index)(8ULL*(index)(rank) + (index)(file)))
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#define SQUARE_MASK_FROM_RF(rank, file) ((index)1ULL << INDEX_FROM_RF(rank,file))
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#define SQUARE_MASK_FROM_INDEX(idx) (1ULL<<(idx))
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enum file_index : index {
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FILE_INDEX_BEGIN,
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FILE_INDEX_A = FILE_INDEX_BEGIN,
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FILE_INDEX_B,
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FILE_INDEX_C,
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FILE_INDEX_D,
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FILE_INDEX_E,
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FILE_INDEX_F,
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FILE_INDEX_G,
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FILE_INDEX_H,
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FILE_INDEX_COUNT,
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};
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enum rank_index : index {
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RANK_INDEX_BEGIN,
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RANK_INDEX_1 = RANK_INDEX_BEGIN,
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RANK_INDEX_2,
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RANK_INDEX_3,
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RANK_INDEX_4,
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RANK_INDEX_5,
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RANK_INDEX_6,
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RANK_INDEX_7,
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RANK_INDEX_8,
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RANK_INDEX_COUNT,
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};
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enum : bitboard {
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FILEMASK_A = FILE_MASK(FILE_INDEX_A),
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FILEMASK_B = FILE_MASK(FILE_INDEX_B),
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FILEMASK_C = FILE_MASK(FILE_INDEX_C),
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FILEMASK_D = FILE_MASK(FILE_INDEX_D),
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FILEMASK_E = FILE_MASK(FILE_INDEX_E),
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FILEMASK_F = FILE_MASK(FILE_INDEX_F),
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FILEMASK_G = FILE_MASK(FILE_INDEX_G),
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FILEMASK_H = FILE_MASK(FILE_INDEX_H),
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RANKMASK_1 = RANK_MASK(RANK_INDEX_1),
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RANKMASK_2 = RANK_MASK(RANK_INDEX_2),
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RANKMASK_3 = RANK_MASK(RANK_INDEX_3),
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RANKMASK_4 = RANK_MASK(RANK_INDEX_4),
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RANKMASK_5 = RANK_MASK(RANK_INDEX_5),
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RANKMASK_6 = RANK_MASK(RANK_INDEX_6),
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RANKMASK_7 = RANK_MASK(RANK_INDEX_7),
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RANKMASK_8 = RANK_MASK(RANK_INDEX_8),
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FILE_SHIFT_RIGHT_GUARD_0 = ~0ULL,
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FILE_SHIFT_RIGHT_GUARD_1 = ~FILEMASK_H,
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FILE_SHIFT_RIGHT_GUARD_2 = ~(FILEMASK_G | FILEMASK_H),
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FILE_SHIFT_RIGHT_GUARD_3 = ~(FILEMASK_F | FILEMASK_G | FILEMASK_H),
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FILE_SHIFT_RIGHT_GUARD_4 = ~(FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
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FILE_SHIFT_RIGHT_GUARD_5 = ~(FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
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FILE_SHIFT_RIGHT_GUARD_6 = ~(FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
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FILE_SHIFT_RIGHT_GUARD_7 = ~(FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G | FILEMASK_H),
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FILE_SHIFT_LEFT_GUARD_0 = ~0ULL,
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FILE_SHIFT_LEFT_GUARD_1 = ~FILEMASK_A,
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FILE_SHIFT_LEFT_GUARD_2 = ~(FILEMASK_A | FILEMASK_B),
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FILE_SHIFT_LEFT_GUARD_3 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C),
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FILE_SHIFT_LEFT_GUARD_4 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D),
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FILE_SHIFT_LEFT_GUARD_5 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E),
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FILE_SHIFT_LEFT_GUARD_6 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F),
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FILE_SHIFT_LEFT_GUARD_7 = ~(FILEMASK_A | FILEMASK_B | FILEMASK_C | FILEMASK_D | FILEMASK_E | FILEMASK_F | FILEMASK_G),
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};
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#define STR(x) #x
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#define SQUARE_MASK_PREFIX SQUARE_MASK_
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#define SQUARES_LIST_BEGIN \
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X(A, 1)
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#define SQUARES_LIST \
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X(A, 1) \
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X(A, 2) \
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X(A, 3) \
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X(A, 4) \
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X(A, 5) \
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X(A, 6) \
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X(A, 7) \
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X(A, 8) \
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X(B, 1) \
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X(B, 2) \
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X(B, 3) \
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X(B, 4) \
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X(B, 5) \
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X(B, 6) \
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X(B, 7) \
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X(B, 8) \
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X(C, 1) \
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X(C, 2) \
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X(C, 3) \
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X(C, 4) \
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X(C, 5) \
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X(C, 6) \
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X(C, 7) \
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X(C, 8) \
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X(D, 1) \
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X(D, 2) \
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X(D, 3) \
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X(D, 4) \
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X(D, 5) \
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X(D, 6) \
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X(D, 7) \
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X(D, 8) \
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X(E, 1) \
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X(E, 2) \
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X(E, 3) \
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X(E, 4) \
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X(E, 5) \
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X(E, 6) \
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X(E, 7) \
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X(E, 8) \
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X(F, 1) \
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X(F, 2) \
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X(F, 3) \
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X(F, 4) \
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X(F, 5) \
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X(F, 6) \
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X(F, 7) \
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X(F, 8) \
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X(G, 1) \
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X(G, 2) \
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X(G, 3) \
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X(G, 4) \
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X(G, 5) \
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X(G, 6) \
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X(G, 7) \
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X(G, 8) \
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X(H, 1) \
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X(H, 2) \
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X(H, 3) \
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X(H, 4) \
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X(H, 5) \
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X(H, 6) \
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X(H, 7) \
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X(H, 8) \
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/* define mask constants: SQUARE_MASK_A1, SQUARE_MASK_A2, ..., SQUARE_MASK_H8 */
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enum : bitboard {
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#define X(file, rank) SQUARE_MASK_##file##rank = SQUARE_MASK_FROM_RF(RANK_INDEX_##rank, FILE_INDEX_##file),
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SQUARES_LIST
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#undef X
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};
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enum square_index : bitboard {
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#define X(file, rank) SQUARE_INDEX_##file##rank = INDEX_FROM_RF(RANK_INDEX_##rank, FILE_INDEX_##file),
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SQUARES_LIST
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SQUARE_INDEX_COUNT,
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#undef X
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/* define iterator begin enum */
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#define X(file, rank) SQUARE_INDEX_BEGIN = SQUARE_INDEX_##file##rank,
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SQUARES_LIST_BEGIN
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#undef X
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};
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const char* square_index_display[SQUARE_INDEX_COUNT] = {
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#define X(file, rank) \
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[SQUARE_INDEX_##file##rank] = STR(file##rank),
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SQUARES_LIST
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#undef X
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};
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const char* square_index_str[SQUARE_INDEX_COUNT] = {
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#define X(file, rank) \
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[SQUARE_INDEX_##file##rank] = STR(SQUARE_INDEX_##file##rank),
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SQUARES_LIST
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#undef X
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};
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#define _FILE_SHIFT_RIGHT_GUARDED(b, n) \
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((((bitboard)(b)) & FILE_SHIFT_RIGHT_GUARD_##n) << ((index)(n) * 1ULL))
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#define _FILE_SHIFT_LEFT_GUARDED(b, n) \
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((((bitboard)(b)) & FILE_SHIFT_LEFT_GUARD_##n) >> ((index)(n) * 1ULL))
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/* FILE_SHIFT_RIGHT_n shifts the bitboard right by n ranks without wrapping */
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#define FILE_SHIFT_RIGHT_1(b) _FILE_SHIFT_RIGHT_GUARDED(b, 1)
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#define FILE_SHIFT_RIGHT_2(b) _FILE_SHIFT_RIGHT_GUARDED(b, 2)
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#define FILE_SHIFT_RIGHT_3(b) _FILE_SHIFT_RIGHT_GUARDED(b, 3)
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#define FILE_SHIFT_RIGHT_4(b) _FILE_SHIFT_RIGHT_GUARDED(b, 4)
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#define FILE_SHIFT_RIGHT_5(b) _FILE_SHIFT_RIGHT_GUARDED(b, 5)
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#define FILE_SHIFT_RIGHT_6(b) _FILE_SHIFT_RIGHT_GUARDED(b, 6)
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#define FILE_SHIFT_RIGHT_7(b) _FILE_SHIFT_RIGHT_GUARDED(b, 7)
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#define FILE_SHIFT_RIGHT_8(b) _FILE_SHIFT_RIGHT_GUARDED(b, 8)
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/* FILE_SHIFT_LEFT_n shifts the bitboard left by n ranks without wrapping */
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#define FILE_SHIFT_LEFT_1(b) _FILE_SHIFT_LEFT_GUARDED(b, 1)
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#define FILE_SHIFT_LEFT_2(b) _FILE_SHIFT_LEFT_GUARDED(b, 2)
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#define FILE_SHIFT_LEFT_3(b) _FILE_SHIFT_LEFT_GUARDED(b, 3)
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#define FILE_SHIFT_LEFT_4(b) _FILE_SHIFT_LEFT_GUARDED(b, 4)
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#define FILE_SHIFT_LEFT_5(b) _FILE_SHIFT_LEFT_GUARDED(b, 5)
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#define FILE_SHIFT_LEFT_6(b) _FILE_SHIFT_LEFT_GUARDED(b, 6)
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#define FILE_SHIFT_LEFT_7(b) _FILE_SHIFT_LEFT_GUARDED(b, 7)
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#define FILE_SHIFT_LEFT_8(b) _FILE_SHIFT_LEFT_GUARDED(b, 8)
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/* RANK_SHIFT_UP_n shifts the bitboard up by n ranks without wrapping */
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#define RANK_SHIFT_UP_1(b) RANK_SHIFT_UP(b, 1)
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#define RANK_SHIFT_UP_2(b) RANK_SHIFT_UP(b, 2)
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#define RANK_SHIFT_UP_3(b) RANK_SHIFT_UP(b, 3)
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#define RANK_SHIFT_UP_4(b) RANK_SHIFT_UP(b, 4)
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#define RANK_SHIFT_UP_5(b) RANK_SHIFT_UP(b, 5)
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#define RANK_SHIFT_UP_6(b) RANK_SHIFT_UP(b, 6)
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#define RANK_SHIFT_UP_7(b) RANK_SHIFT_UP(b, 7)
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#define RANK_SHIFT_UP_8(b) RANK_SHIFT_UP(b, 8)
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/* RANK_SHIFT_DOWN_n shifts the bitboard down by n ranks without wrapping */
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#define RANK_SHIFT_DOWN_1(b) RANK_SHIFT_DOWN(b, 1)
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#define RANK_SHIFT_DOWN_2(b) RANK_SHIFT_DOWN(b, 2)
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#define RANK_SHIFT_DOWN_3(b) RANK_SHIFT_DOWN(b, 3)
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#define RANK_SHIFT_DOWN_4(b) RANK_SHIFT_DOWN(b, 4)
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#define RANK_SHIFT_DOWN_5(b) RANK_SHIFT_DOWN(b, 5)
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#define RANK_SHIFT_DOWN_6(b) RANK_SHIFT_DOWN(b, 6)
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#define RANK_SHIFT_DOWN_7(b) RANK_SHIFT_DOWN(b, 7)
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#define RANK_SHIFT_DOWN_8(b) RANK_SHIFT_DOWN(b, 8)
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/* MISC
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* ============*/
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/* TODO: Put these struct definition in a sensible category */
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/* `struct magic` is used by magic bitboard lookups, see
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* rook_attacks_from_index and bishop_attacks_from_index */
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struct magic {
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bitboard mask;
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bitboard magic;
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};
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/* BITBOARD PRIMITIVES
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* ======================== */
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static index bitboard_lsb(bitboard p)
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{
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return __builtin_ffsll(p);
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}
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static uint64_t bitboard_popcount(bitboard b)
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{
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return (uint64_t)__builtin_popcountll(b);
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}
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static inline index index_to_file(enum square_index p)
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{
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return p % 8ULL;
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}
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static inline index index_to_rank(enum square_index p)
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{
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return p / 8ULL;
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}
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static bitboard cardinals_from_index(enum square_index p)
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{
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/* might benefit from a lookup table */
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return (FILE_MASK(index_to_file(p)) | RANK_MASK(index_to_rank(p)))
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& ~SQUARE_MASK_FROM_INDEX(p);
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}
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static bitboard diagonals_from_index(enum square_index sq)
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{
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const enum rank_index rank = index_to_rank(sq);
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const enum file_index file = index_to_file(sq);
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bitboard mask = 0ULL;
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/* Ensure signed-underflow detection rules match your style */
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_Static_assert(((enum rank_index)0) - ((enum rank_index)1) > ((enum rank_index)0));
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_Static_assert(((enum file_index)0) - ((enum file_index)1) > ((enum file_index)0));
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enum rank_index r;
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enum file_index f;
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for (r = rank+1, f = file+1;
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r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
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++r, ++f)
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{
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mask |= SQUARE_MASK_FROM_RF(r, f);
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}
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/* NW (rank+1, file-1) */
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for (r = rank+1, f = file-1;
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r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
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++r, --f)
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{
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mask |= SQUARE_MASK_FROM_RF(r, f);
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}
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/* SE (rank-1, file+1) */
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for (r = rank-1, f = file+1;
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r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
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--r, ++f)
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{
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mask |= SQUARE_MASK_FROM_RF(r, f);
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}
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/* SW (rank-1, file-1) */
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for (r = rank-1, f = file-1;
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r <= RANK_INDEX_8 && f <= FILE_INDEX_H;
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--r, --f)
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{
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mask |= SQUARE_MASK_FROM_RF(r, f);
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}
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return mask;
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}
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/* PIECE ATTACKS
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* ================== */
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static bitboard knight_attacks(bitboard p)
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{
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const bitboard l1 = FILE_SHIFT_RIGHT_1(p & ~FILEMASK_H);
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const bitboard l2 = FILE_SHIFT_RIGHT_2(p & ~(FILEMASK_G | FILEMASK_H));
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const bitboard r1 = FILE_SHIFT_LEFT_1 (p & ~FILEMASK_A);
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const bitboard r2 = FILE_SHIFT_LEFT_2 (p & ~(FILEMASK_A | FILEMASK_B));
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const bitboard h1 = l1 | r1;
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const bitboard h2 = l2 | r2;
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return RANK_SHIFT_UP_2(h1)
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| RANK_SHIFT_DOWN_2(h1)
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| RANK_SHIFT_UP_1(h2)
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| RANK_SHIFT_DOWN_1(h2);
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}
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/* rook_attacks_from_index computes rook attack sets from an index, and its
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* purpose is code generation (the magic bitboard).
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*
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* It does not discriminate between friendly and opponent pieces, the caller
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* should therefore do something like:
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* ```
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* rook_attacks_from_index(p, friendly_occ | opponent_occ) & ~friendly_occ
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* ```
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* */
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static bitboard rook_attacks_from_index_slow(enum square_index sq, bitboard occ)
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{
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const enum rank_index rank = index_to_rank(sq);
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const enum file_index file = index_to_file(sq);
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bitboard atk = 0ULL;
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/* following loops assume rank and file types are unsigned, which relies on C23 enums */
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_Static_assert(((enum rank_index)0) - ((enum rank_index)1) > ((enum rank_index)0));
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_Static_assert(((enum file_index)0) - ((enum file_index)1) > ((enum file_index)0));
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for (enum rank_index walk_rank = rank+1; walk_rank <= RANK_INDEX_8; ++walk_rank) {
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const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, file);
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atk |= sq;
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if (occ & sq) {
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break;
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}
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}
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for (enum rank_index walk_rank = rank-1; walk_rank <= RANK_INDEX_8; --walk_rank) {
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const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, file);
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atk |= sq;
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if (occ & sq) {
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break;
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}
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}
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for (enum file_index walk_file = file+1; walk_file <= FILE_INDEX_H; ++walk_file) {
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const bitboard sq = SQUARE_MASK_FROM_RF(rank, walk_file);
|
|
atk |= sq;
|
|
if (occ & sq) {
|
|
break;
|
|
}
|
|
}
|
|
for (enum file_index walk_file = file-1; walk_file <= FILE_INDEX_H; --walk_file) {
|
|
const bitboard sq = SQUARE_MASK_FROM_RF(rank, walk_file);
|
|
atk |= sq;
|
|
if (occ & sq) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return atk;
|
|
}
|
|
|
|
static bitboard rook_attacks_from_index(enum square_index sq, bitboard occ)
|
|
{
|
|
#ifdef CODEGEN
|
|
return 0ULL;
|
|
#else
|
|
#if ! __has_include("mbb_rook.h")
|
|
#error "compile with -DCODEGEN and run once to generate required header files"
|
|
#else
|
|
|
|
/* defines
|
|
- `mbb_rook[SQUARE_INDEX_COUNT]`
|
|
- `bitboard rook_attacks[SQUARE_INDEX_COUNT][1<<12ULL] */
|
|
#include "mbb_rook.h"
|
|
|
|
const struct magic m = mbb_rook[sq];
|
|
occ &= m.mask;
|
|
occ *= m.magic;
|
|
occ >>= (64ULL-12ULL);
|
|
return rook_attacks[sq][occ];
|
|
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
static bitboard rook_attacks(bitboard p, bitboard occ)
|
|
{
|
|
bitboard b = 0ULL;
|
|
while (p) {
|
|
const index lsb = bitboard_lsb(p) - 1;
|
|
p &= ~(1ULL<<(lsb));
|
|
b |= rook_attacks_from_index(lsb, occ);
|
|
}
|
|
return b;
|
|
}
|
|
|
|
/* bishop_attacks_from_index computes bishop attack sets from an index, and its
|
|
* purpose is code generation (the magic bitboard).
|
|
*
|
|
* It does not discriminate between friendly and opponent pieces, the caller
|
|
* should therefore do something like:
|
|
* ```
|
|
* bishop_attacks_from_index(p, occ) & ~friendly_occ
|
|
* ```
|
|
* */
|
|
static bitboard bishop_attacks_from_index_slow(enum square_index sq, bitboard occ)
|
|
{
|
|
const enum rank_index rank = index_to_rank(sq);
|
|
const enum file_index file = index_to_file(sq);
|
|
|
|
bitboard atk = 0ULL;
|
|
|
|
/* following loops assume rank and file types are unsigned, which relies on C23 enums */
|
|
_Static_assert(((enum rank_index)0) - ((enum rank_index)1) > ((enum rank_index)0));
|
|
_Static_assert(((enum file_index)0) - ((enum file_index)1) > ((enum file_index)0));
|
|
|
|
enum rank_index walk_rank;
|
|
enum file_index walk_file;
|
|
for (walk_rank = rank+1, walk_file = file+1;
|
|
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
|
|
++walk_rank, ++walk_file) {
|
|
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
|
|
atk |= sq;
|
|
if (occ & sq) {
|
|
break;
|
|
}
|
|
}
|
|
for (walk_rank = rank+1, walk_file = file-1;
|
|
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
|
|
++walk_rank, --walk_file) {
|
|
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
|
|
atk |= sq;
|
|
if (occ & sq) {
|
|
break;
|
|
}
|
|
}
|
|
for (walk_rank = rank-1, walk_file = file+1;
|
|
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
|
|
--walk_rank, ++walk_file) {
|
|
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
|
|
atk |= sq;
|
|
if (occ & sq) {
|
|
break;
|
|
}
|
|
}
|
|
for (walk_rank = rank-1, walk_file = file-1;
|
|
walk_rank <= RANK_INDEX_8 && walk_file <= FILE_INDEX_H;
|
|
--walk_rank, --walk_file) {
|
|
const bitboard sq = SQUARE_MASK_FROM_RF(walk_rank, walk_file);
|
|
atk |= sq;
|
|
if (occ & sq) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return atk;
|
|
}
|
|
|
|
static bitboard bishop_attacks_from_index(enum square_index sq, bitboard occ)
|
|
{
|
|
#ifdef CODEGEN
|
|
return 0ULL;
|
|
#else
|
|
#if ! __has_include("mbb_bishop.h")
|
|
#error "compile with -DCODEGEN and run once to generate required header files"
|
|
#else
|
|
|
|
/* defines
|
|
- `mbb_bishop[SQUARE_INDEX_COUNT]`
|
|
- `bitboard bishop_attacks[SQUARE_INDEX_COUNT][1<<9ULL] */
|
|
#include "mbb_bishop.h"
|
|
const struct magic m = mbb_bishop[sq];
|
|
occ &= m.mask;
|
|
occ *= m.magic;
|
|
occ >>= (64ULL-9ULL);
|
|
return bishop_attacks[sq][occ];
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
static bitboard bishop_attacks(bitboard p, bitboard occ)
|
|
{
|
|
bitboard b = 0ULL;
|
|
while (p) {
|
|
const index lsb = bitboard_lsb(p) - 1;
|
|
p &= ~(1ULL<<(lsb));
|
|
b |= bishop_attacks_from_index(lsb, occ);
|
|
}
|
|
return b;
|
|
}
|
|
|
|
static inline bitboard pawn_white_moves(bitboard p, bitboard empty)
|
|
{
|
|
/* Assumptions:
|
|
- empty = ~(black_occupied | white_occupied);
|
|
*/
|
|
|
|
const bitboard single_push = RANK_SHIFT_UP(p, 1) & empty;
|
|
|
|
const bitboard double_push =
|
|
RANK_SHIFT_UP(single_push & RANKMASK_3, 1) & empty;
|
|
|
|
return single_push | double_push;
|
|
}
|
|
|
|
static inline bitboard pawn_white_attacks(bitboard p, bitboard ep_targets, bitboard black_occupied)
|
|
{
|
|
const bitboard up = RANK_SHIFT_UP(p, 1);
|
|
const bitboard captures_right = FILE_SHIFT_RIGHT(up, 1) & ~FILEMASK_H;
|
|
const bitboard captures_left = FILE_SHIFT_LEFT(up, 1) & ~FILEMASK_A;
|
|
|
|
return (captures_right | captures_left) & (black_occupied | ep_targets);
|
|
}
|
|
|
|
static inline bitboard pawn_black_moves(bitboard p, bitboard empty)
|
|
{
|
|
/* Assumptions:
|
|
- empty = ~(black_occupied | white_occupied);
|
|
*/
|
|
|
|
const bitboard single_push = RANK_SHIFT_DOWN(p, 1) & empty;
|
|
|
|
const bitboard double_push =
|
|
RANK_SHIFT_DOWN(single_push & RANKMASK_6, 1) & empty;
|
|
|
|
return single_push | double_push;
|
|
}
|
|
|
|
static inline bitboard pawn_black_attacks(bitboard p, bitboard ep_targets, bitboard white_occupied)
|
|
{
|
|
const bitboard down = RANK_SHIFT_UP(p, 1);
|
|
const bitboard captures_right = FILE_SHIFT_RIGHT(down, 1) & ~FILEMASK_H;
|
|
const bitboard captures_left = FILE_SHIFT_LEFT(down, 1) & ~FILEMASK_A;
|
|
|
|
return (captures_right | captures_left) & (white_occupied | ep_targets);
|
|
}
|
|
|
|
static bitboard king_attacks(enum square_index sq)
|
|
{
|
|
/* candidate for improvement */
|
|
const bitboard n = RANK_SHIFT_UP(sq, 1);
|
|
const bitboard s = RANK_SHIFT_DOWN(sq, 1);
|
|
const bitboard w = FILE_SHIFT_LEFT(sq, 1);
|
|
const bitboard e = FILE_SHIFT_RIGHT(sq, 1);
|
|
|
|
const bitboard nw = FILE_SHIFT_LEFT(n, 1);
|
|
const bitboard ne = FILE_SHIFT_RIGHT(n, 1);
|
|
const bitboard sw = FILE_SHIFT_RIGHT(s, 1);
|
|
const bitboard se = FILE_SHIFT_LEFT(s, 1);
|
|
|
|
return n | s | w | e | nw | ne | sw | se;
|
|
}
|
|
|
|
|
|
/* BOARD
|
|
* ================= */
|
|
enum player : index {
|
|
PLAYER_BEGIN,
|
|
PLAYER_WHITE = PLAYER_BEGIN,
|
|
PLAYER_BLACK,
|
|
PLAYER_COUNT,
|
|
};
|
|
|
|
enum piece : index {
|
|
PIECE_BEGIN,
|
|
PIECE_PAWN = PIECE_BEGIN,
|
|
PIECE_KING,
|
|
PIECE_QUEEN,
|
|
PIECE_BISHOP,
|
|
PIECE_ROOK,
|
|
PIECE_KNIGHT,
|
|
PIECE_COUNT,
|
|
};
|
|
|
|
const char piece_char[PLAYER_COUNT][PIECE_COUNT] = {
|
|
[PLAYER_WHITE] = {
|
|
[PIECE_PAWN] = 'P',
|
|
[PIECE_KING] = 'K',
|
|
[PIECE_QUEEN] = 'Q',
|
|
[PIECE_BISHOP] = 'B',
|
|
[PIECE_ROOK] = 'R',
|
|
[PIECE_KNIGHT] = 'N',
|
|
},
|
|
[PLAYER_BLACK] = {
|
|
[PIECE_PAWN] = 'p',
|
|
[PIECE_KING] = 'k',
|
|
[PIECE_QUEEN] = 'q',
|
|
[PIECE_BISHOP] = 'b',
|
|
[PIECE_ROOK] = 'r',
|
|
[PIECE_KNIGHT] = 'n',
|
|
}
|
|
};
|
|
|
|
const int piece_unicode[PLAYER_COUNT][PIECE_COUNT] = {
|
|
[PLAYER_WHITE] = {
|
|
[PIECE_PAWN] = 0x2659,
|
|
[PIECE_KING] = 0x2654,
|
|
[PIECE_QUEEN] = 0x2655,
|
|
[PIECE_BISHOP] = 0x2657,
|
|
[PIECE_ROOK] = 0x2656,
|
|
[PIECE_KNIGHT] = 0x2658,
|
|
},
|
|
[PLAYER_BLACK] = {
|
|
[PIECE_PAWN] = 0x265F,
|
|
[PIECE_KING] = 0x265A,
|
|
[PIECE_QUEEN] = 0x265B,
|
|
[PIECE_BISHOP] = 0x265D,
|
|
[PIECE_ROOK] = 0x265C,
|
|
[PIECE_KNIGHT] = 0x265E,
|
|
}
|
|
};
|
|
|
|
struct board {
|
|
bitboard pieces[PLAYER_COUNT][PIECE_COUNT];
|
|
bitboard enpassent_targets[PLAYER_COUNT];
|
|
bitboard occupied[PLAYER_COUNT];
|
|
};
|
|
|
|
#define BOARD_INITIAL (struct board) { \
|
|
.pieces = { \
|
|
[PLAYER_WHITE] = { \
|
|
[PIECE_PAWN] = RANKMASK_2, \
|
|
[PIECE_ROOK] = SQUARE_MASK_A1 | SQUARE_MASK_H1, \
|
|
[PIECE_KNIGHT] = SQUARE_MASK_B1 | SQUARE_MASK_G1, \
|
|
[PIECE_BISHOP] = SQUARE_MASK_C1 | SQUARE_MASK_F1, \
|
|
[PIECE_QUEEN] = SQUARE_MASK_D1, \
|
|
[PIECE_KING] = SQUARE_MASK_E1, \
|
|
}, \
|
|
[PLAYER_BLACK] = { \
|
|
[PIECE_PAWN] = RANKMASK_7, \
|
|
[PIECE_ROOK] = SQUARE_MASK_A8 | SQUARE_MASK_H8, \
|
|
[PIECE_KNIGHT] = SQUARE_MASK_B8 | SQUARE_MASK_G8, \
|
|
[PIECE_BISHOP] = SQUARE_MASK_C8 | SQUARE_MASK_F8, \
|
|
[PIECE_QUEEN] = SQUARE_MASK_D8, \
|
|
[PIECE_KING] = SQUARE_MASK_E8, \
|
|
} \
|
|
} \
|
|
}
|
|
|
|
void board_print(struct board* b, FILE* out)
|
|
{
|
|
int buf[8][8] = {0};
|
|
|
|
for (size_t i = 0; i < 8; i++) {
|
|
for (size_t i = 0; i < 8; i++) {
|
|
buf[i][i] = 0;
|
|
}
|
|
}
|
|
|
|
for (enum player player = PLAYER_BEGIN; player < PLAYER_COUNT; player++) {
|
|
for (enum piece piece = PIECE_BEGIN; piece < PIECE_COUNT; piece++) {
|
|
bitboard x = b->pieces[player][piece];
|
|
|
|
for (index i = 7; i < 8; i--) {
|
|
for (index j = 0; j < 8; j++) {
|
|
if (x & (1ULL<<(i*8+j))) {
|
|
buf[i][j] = piece_unicode[player][piece];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* see: https://en.wikipedia.org/wiki/ANSI_escape_code#Colors */
|
|
setlocale(LC_ALL, "");
|
|
for (index i = 7; i < 8; i--) {
|
|
fprintf(out, "\033[0m"); /* reset background color */
|
|
fprintf(out, "%"INDEX_FMT" ", i+1);
|
|
for (index j = 0; j < 8; j++) {
|
|
/* 45: magenta, 47: white */
|
|
fprintf(out, "\033[%d;%dm", 30, (i+j) % 2 ? 45 : 47);
|
|
if (buf[i][j]) {
|
|
fprintf(out, "%lc ", buf[i][j]);
|
|
} else {
|
|
fprintf(out, " "); /* idk why this hack is needed but "%lc "
|
|
is not working when buf[i][j] = ' ' */
|
|
}
|
|
}
|
|
fprintf(out, "\033[0m"); /* reset background color */
|
|
fprintf(out, "\n");
|
|
}
|
|
fprintf(out, " A B C D E F G H \n");
|
|
}
|
|
|
|
/* debug functions
|
|
* =============== */
|
|
|
|
void bitboard_print(bitboard b, FILE* out)
|
|
{
|
|
setlocale(LC_ALL, "");
|
|
fprintf(out, "\n");
|
|
for (index i = 7; i < 8; i--) {
|
|
fprintf(out, "\033[0m"); /* reset background color */
|
|
fprintf(out, "%"INDEX_FMT" ", i+1);
|
|
for (index j = 0; j < 8; j++) {
|
|
const index n = i*8+j;
|
|
int color;
|
|
if ((b >> n) & 1) {
|
|
/* 41: red */
|
|
color = 41;
|
|
} else {
|
|
/* 45: magenta, 47: white */
|
|
color = (i+j)%2 ? 45 : 47;
|
|
}
|
|
fprintf(out, "\033[30;%dm", color);
|
|
fprintf(out, " ");
|
|
}
|
|
fprintf(out, "\033[0m"); /* reset background color */
|
|
fprintf(out, "\n");
|
|
}
|
|
fprintf(out, " A B C D E F G H \n");
|
|
}
|
|
|