diff --git a/src/Makefile b/src/Makefile index 0b19856797f..f12b68c4a88 100644 --- a/src/Makefile +++ b/src/Makefile @@ -37,8 +37,8 @@ PGOBENCH = ./$(EXE) bench ### Source and object files SRCS = benchmark.cpp bitboard.cpp evaluate.cpp main.cpp misc.cpp movegen.cpp \ - movepick.cpp pawns.cpp position.cpp search.cpp thread.cpp timeman.cpp \ - tt.cpp uci.cpp ucioption.cpp tune.cpp syzygy/tbprobe.cpp + movepick.cpp position.cpp search.cpp thread.cpp timeman.cpp tt.cpp \ + uci.cpp ucioption.cpp tune.cpp syzygy/tbprobe.cpp OBJS = $(notdir $(SRCS:.cpp=.o)) diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 68999778b3c..5fdc07da113 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -26,7 +26,6 @@ #include "bitboard.h" #include "evaluate.h" -#include "pawns.h" #include "thread.h" namespace { diff --git a/src/pawns.cpp b/src/pawns.cpp deleted file mode 100644 index 662e8e9a61c..00000000000 --- a/src/pawns.cpp +++ /dev/null @@ -1,284 +0,0 @@ -/* - Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad - - Stockfish 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. - - Stockfish 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 . -*/ - -#include -#include - -#include "bitboard.h" -#include "pawns.h" -#include "position.h" -#include "thread.h" - -namespace { - - #define V Value - #define S(mg, eg) make_score(mg, eg) - - // Pawn penalties - constexpr Score Backward = S( 9, 24); - constexpr Score Doubled = S(11, 56); - constexpr Score Isolated = S( 5, 15); - constexpr Score WeakLever = S( 0, 56); - constexpr Score WeakUnopposed = S(13, 27); - - // Bonus for blocked pawns at 5th or 6th rank - constexpr Score BlockedPawn[2] = { S(-11, -4), S(-3, 4) }; - - constexpr Score BlockedStorm[RANK_NB] = { - S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2) - }; - - // Connected pawn bonus - constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 }; - - // Strength of pawn shelter for our king by [distance from edge][rank]. - // RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king. - constexpr Value ShelterStrength[int(FILE_NB) / 2][RANK_NB] = { - { V( -6), V( 81), V( 93), V( 58), V( 39), V( 18), V( 25) }, - { V(-43), V( 61), V( 35), V(-49), V(-29), V(-11), V( -63) }, - { V(-10), V( 75), V( 23), V( -2), V( 32), V( 3), V( -45) }, - { V(-39), V(-13), V(-29), V(-52), V(-48), V(-67), V(-166) } - }; - - // Danger of enemy pawns moving toward our king by [distance from edge][rank]. - // RANK_1 = 0 is used for files where the enemy has no pawn, or their pawn - // is behind our king. Note that UnblockedStorm[0][1-2] accommodate opponent pawn - // on edge, likely blocked by our king. - constexpr Value UnblockedStorm[int(FILE_NB) / 2][RANK_NB] = { - { V( 85), V(-289), V(-166), V(97), V(50), V( 45), V( 50) }, - { V( 46), V( -25), V( 122), V(45), V(37), V(-10), V( 20) }, - { V( -6), V( 51), V( 168), V(34), V(-2), V(-22), V(-14) }, - { V(-15), V( -11), V( 101), V( 4), V(11), V(-15), V(-29) } - }; - - #undef S - #undef V - - - /// evaluate() calculates a score for the static pawn structure of the given position. - /// We cannot use the location of pieces or king in this function, as the evaluation - /// of the pawn structure will be stored in a small cache for speed reasons, and will - /// be re-used even when the pieces have moved. - - template - Score evaluate(const Position& pos, Pawns::Entry* e) { - - constexpr Color Them = ~Us; - constexpr Direction Up = pawn_push(Us); - - Bitboard neighbours, stoppers, support, phalanx, opposed; - Bitboard lever, leverPush, blocked; - Square s; - bool backward, passed, doubled; - Score score = SCORE_ZERO; - Bitboard b = pos.pieces(Us, PAWN); - - Bitboard ourPawns = pos.pieces( Us, PAWN); - Bitboard theirPawns = pos.pieces(Them, PAWN); - - Bitboard doubleAttackThem = pawn_double_attacks_bb(theirPawns); - - e->passedPawns[Us] = 0; - e->kingSquares[Us] = SQ_NONE; - e->pawnAttacks[Us] = e->pawnAttacksSpan[Us] = pawn_attacks_bb(ourPawns); - e->blockedCount += popcount(shift(ourPawns) & (theirPawns | doubleAttackThem)); - - // Loop through all pawns of the current color and score each pawn - while (b) { - s = pop_lsb(&b); - - assert(pos.piece_on(s) == make_piece(Us, PAWN)); - - Rank r = relative_rank(Us, s); - - // Flag the pawn - opposed = theirPawns & forward_file_bb(Us, s); - blocked = theirPawns & (s + Up); - stoppers = theirPawns & passed_pawn_span(Us, s); - lever = theirPawns & pawn_attacks_bb(Us, s); - leverPush = theirPawns & pawn_attacks_bb(Us, s + Up); - doubled = ourPawns & (s - Up); - neighbours = ourPawns & adjacent_files_bb(s); - phalanx = neighbours & rank_bb(s); - support = neighbours & rank_bb(s - Up); - - // A pawn is backward when it is behind all pawns of the same color on - // the adjacent files and cannot safely advance. - backward = !(neighbours & forward_ranks_bb(Them, s + Up)) - && (leverPush | blocked); - - // Compute additional span if pawn is not backward nor blocked - if (!backward && !blocked) - e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s); - - // A pawn is passed if one of the three following conditions is true: - // (a) there is no stoppers except some levers - // (b) the only stoppers are the leverPush, but we outnumber them - // (c) there is only one front stopper which can be levered. - // (Refined in Evaluation::passed) - passed = !(stoppers ^ lever) - || ( !(stoppers ^ leverPush) - && popcount(phalanx) >= popcount(leverPush)) - || ( stoppers == blocked && r >= RANK_5 - && (shift(support) & ~(theirPawns | doubleAttackThem))); - - passed &= !(forward_file_bb(Us, s) & ourPawns); - - // Passed pawns will be properly scored later in evaluation when we have - // full attack info. - if (passed) - e->passedPawns[Us] |= s; - - // Score this pawn - if (support | phalanx) - { - int v = Connected[r] * (2 + bool(phalanx) - bool(opposed)) - + 21 * popcount(support); - - score += make_score(v, v * (r - 2) / 4); - } - - else if (!neighbours) - { - if ( opposed - && (ourPawns & forward_file_bb(Them, s)) - && !(theirPawns & adjacent_files_bb(s))) - score -= Doubled; - else - score -= Isolated - + WeakUnopposed * !opposed; - } - - else if (backward) - score -= Backward - + WeakUnopposed * !opposed; - - if (!support) - score -= Doubled * doubled - + WeakLever * more_than_one(lever); - - if (blocked && r > RANK_4) - score += BlockedPawn[r-4]; - } - - return score; - } - -} // namespace - -namespace Pawns { - - -/// Pawns::probe() looks up the current position's pawns configuration in -/// the pawns hash table. It returns a pointer to the Entry if the position -/// is found. Otherwise a new Entry is computed and stored there, so we don't -/// have to recompute all when the same pawns configuration occurs again. - -Entry* probe(const Position& pos) { - - Key key = pos.pawn_key(); - Entry* e = pos.this_thread()->pawnsTable[key]; - - if (e->key == key) - return e; - - e->key = key; - e->blockedCount = 0; - e->scores[WHITE] = evaluate(pos, e); - e->scores[BLACK] = evaluate(pos, e); - - return e; -} - - -/// Entry::evaluate_shelter() calculates the shelter bonus and the storm -/// penalty for a king, looking at the king file and the two closest files. - -template -Score Entry::evaluate_shelter(const Position& pos, Square ksq) const { - - constexpr Color Them = ~Us; - - Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq); - Bitboard ourPawns = b & pos.pieces(Us) & ~pawnAttacks[Them]; - Bitboard theirPawns = b & pos.pieces(Them); - - Score bonus = make_score(5, 5); - - File center = Utility::clamp(file_of(ksq), FILE_B, FILE_G); - for (File f = File(center - 1); f <= File(center + 1); ++f) - { - b = ourPawns & file_bb(f); - int ourRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0; - - b = theirPawns & file_bb(f); - int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0; - - int d = edge_distance(f); - bonus += make_score(ShelterStrength[d][ourRank], 0); - - if (ourRank && (ourRank == theirRank - 1)) - bonus -= BlockedStorm[theirRank]; - else - bonus -= make_score(UnblockedStorm[d][theirRank], 0); - } - - return bonus; -} - - -/// Entry::do_king_safety() calculates a bonus for king safety. It is called only -/// when king square changes, which is about 20% of total king_safety() calls. - -template -Score Entry::do_king_safety(const Position& pos) { - - Square ksq = pos.square(Us); - kingSquares[Us] = ksq; - castlingRights[Us] = pos.castling_rights(Us); - auto compare = [](Score a, Score b) { return mg_value(a) < mg_value(b); }; - - Score shelter = evaluate_shelter(pos, ksq); - - // If we can castle use the bonus after castling if it is bigger - - if (pos.can_castle(Us & KING_SIDE)) - shelter = std::max(shelter, evaluate_shelter(pos, relative_square(Us, SQ_G1)), compare); - - if (pos.can_castle(Us & QUEEN_SIDE)) - shelter = std::max(shelter, evaluate_shelter(pos, relative_square(Us, SQ_C1)), compare); - - // In endgame we like to bring our king near our closest pawn - Bitboard pawns = pos.pieces(Us, PAWN); - int minPawnDist = 6; - - if (pawns & attacks_bb(ksq)) - minPawnDist = 1; - else while (pawns) - minPawnDist = std::min(minPawnDist, distance(ksq, pop_lsb(&pawns))); - - return shelter - make_score(0, 16 * minPawnDist); -} - -// Explicit template instantiation -template Score Entry::do_king_safety(const Position& pos); -template Score Entry::do_king_safety(const Position& pos); - -} // namespace Pawns diff --git a/src/pawns.h b/src/pawns.h deleted file mode 100644 index e6098069025..00000000000 --- a/src/pawns.h +++ /dev/null @@ -1,72 +0,0 @@ -/* - Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad - - Stockfish 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. - - Stockfish 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 . -*/ - -#ifndef PAWNS_H_INCLUDED -#define PAWNS_H_INCLUDED - -#include "misc.h" -#include "position.h" -#include "types.h" - -namespace Pawns { - -/// Pawns::Entry contains various information about a pawn structure. A lookup -/// to the pawn hash table (performed by calling the probe function) returns a -/// pointer to an Entry object. - -struct Entry { - - Score pawn_score(Color c) const { return scores[c]; } - Bitboard pawn_attacks(Color c) const { return pawnAttacks[c]; } - Bitboard passed_pawns(Color c) const { return passedPawns[c]; } - Bitboard pawn_attacks_span(Color c) const { return pawnAttacksSpan[c]; } - int passed_count() const { return popcount(passedPawns[WHITE] | passedPawns[BLACK]); } - int blocked_count() const { return blockedCount; } - - template - Score king_safety(const Position& pos) { - return kingSquares[Us] == pos.square(Us) && castlingRights[Us] == pos.castling_rights(Us) - ? kingSafety[Us] : (kingSafety[Us] = do_king_safety(pos)); - } - - template - Score do_king_safety(const Position& pos); - - template - Score evaluate_shelter(const Position& pos, Square ksq) const; - - Key key; - Score scores[COLOR_NB]; - Bitboard passedPawns[COLOR_NB]; - Bitboard pawnAttacks[COLOR_NB]; - Bitboard pawnAttacksSpan[COLOR_NB]; - Square kingSquares[COLOR_NB]; - Score kingSafety[COLOR_NB]; - int castlingRights[COLOR_NB]; - int blockedCount; -}; - -typedef HashTable Table; - -Entry* probe(const Position& pos); - -} // namespace Pawns - -#endif // #ifndef PAWNS_H_INCLUDED diff --git a/src/thread.h b/src/thread.h index 7a363fe3ea7..3fdd8b39ad1 100644 --- a/src/thread.h +++ b/src/thread.h @@ -28,7 +28,6 @@ #include #include "movepick.h" -#include "pawns.h" #include "position.h" #include "search.h" #include "thread_win32_osx.h" @@ -57,7 +56,6 @@ class Thread { void wait_for_search_finished(); int best_move_count(Move move) const; - Pawns::Table pawnsTable; size_t pvIdx, pvLast; uint64_t ttHitAverage; int selDepth, nmpMinPly;