X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=aa6f7c19bc9ac9aa45b5368133d7010f155f32ee;hp=582978e69d0c3f1fb2c6535c82d71f564cc85aa7;hb=877b468e3e8a3b7f7482266007237c6974f7f282;hpb=c7866a4215c31d7d0af8e8550fbf8c13f6ea1d1a diff --git a/src/movepick.cpp b/src/movepick.cpp index 582978e6..aa6f7c19 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2009 Marco Costalba + Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, 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 @@ -70,17 +70,18 @@ namespace { /// search captures, promotions and some checks) and about how important good /// move ordering is at the current node. -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, - const History& h, SearchStack* ss) : pos(p), H(h) { +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, + SearchStack* ss, Value beta) : pos(p), H(h) { int searchTT = ttm; ttMoves[0].move = ttm; - lastBadCapture = badCaptures; + badCaptureThreshold = 0; + badCaptures = moves + MOVES_MAX; pinned = p.pinned_pieces(pos.side_to_move()); if (ss && !p.is_check()) { - ttMoves[1].move = (ss->mateKiller == ttm)? MOVE_NONE : ss->mateKiller; + ttMoves[1].move = (ss->mateKiller == ttm) ? MOVE_NONE : ss->mateKiller; searchTT |= ttMoves[1].move; killers[0].move = ss->killers[0]; killers[1].move = ss->killers[1]; @@ -89,9 +90,16 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, if (p.is_check()) phasePtr = EvasionsPhaseTable; - else if (d > Depth(0)) + else if (d > DEPTH_ZERO) + { + // Consider sligtly negative captures as good if at low + // depth and far from beta. + if (ss && ss->eval < beta - PawnValueMidgame && d < 3 * ONE_PLY) + badCaptureThreshold = -PawnValueMidgame; + phasePtr = MainSearchPhaseTable; - else if (d == Depth(0)) + } + else if (d >= DEPTH_QS_CHECKS) phasePtr = QsearchWithChecksPhaseTable; else { @@ -104,7 +112,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, searchTT = ttMoves[0].move = MOVE_NONE; } - phasePtr += !searchTT - 1; + phasePtr += int(!searchTT) - 1; go_next_phase(); } @@ -124,7 +132,7 @@ void MovePicker::go_next_phase() { return; case PH_GOOD_CAPTURES: - lastMove = generate_captures(pos, moves); + lastMove = generate(pos, moves); score_captures(); return; @@ -134,32 +142,31 @@ void MovePicker::go_next_phase() { return; case PH_NONCAPTURES: - lastMove = generate_noncaptures(pos, moves); + lastMove = generate(pos, moves); score_noncaptures(); sort_moves(moves, lastMove, &lastGoodNonCapture); return; case PH_BAD_CAPTURES: - // Bad captures SEE value is already calculated so just sort them - // to get SEE move ordering. + // Bad captures SEE value is already calculated so just pick + // them in order to get SEE move ordering. curMove = badCaptures; - lastMove = lastBadCapture; + lastMove = moves + MOVES_MAX; return; case PH_EVASIONS: assert(pos.is_check()); - lastMove = generate_evasions(pos, moves); - score_evasions_or_checks(); + lastMove = generate(pos, moves); + score_evasions(); return; case PH_QCAPTURES: - lastMove = generate_captures(pos, moves); + lastMove = generate(pos, moves); score_captures(); return; case PH_QCHECKS: - lastMove = generate_non_capture_checks(pos, moves); - score_evasions_or_checks(); + lastMove = generate(pos, moves); return; case PH_STOP: @@ -220,11 +227,11 @@ void MovePicker::score_noncaptures() { from = move_from(m); to = move_to(m); piece = pos.piece_on(from); - cur->score = H.move_ordering_score(piece, to); + cur->score = H.value(piece, to) + H.gain(piece, to); } } -void MovePicker::score_evasions_or_checks() { +void MovePicker::score_evasions() { // Try good captures ordered by MVV/LVA, then non-captures if // destination square is not under attack, ordered by history // value, and at the end bad-captures and non-captures with a @@ -240,12 +247,12 @@ void MovePicker::score_evasions_or_checks() { { m = cur->move; if ((seeScore = pos.see_sign(m)) < 0) - cur->score = seeScore - HistoryMax; // Be sure are at the bottom + cur->score = seeScore - History::MaxValue; // Be sure we are at the bottom else if (pos.move_is_capture(m)) cur->score = pos.midgame_value_of_piece_on(move_to(m)) - - pos.type_of_piece_on(move_from(m)) + HistoryMax; + - pos.type_of_piece_on(move_from(m)) + History::MaxValue; else - cur->score = H.move_ordering_score(pos.piece_on(move_from(m)), move_to(m)); + cur->score = H.value(pos.piece_on(move_from(m)), move_to(m)); } } @@ -282,24 +289,22 @@ Move MovePicker::get_next_move() { { // Check for a non negative SEE now int seeValue = pos.see_sign(move); - if (seeValue >= 0) + if (seeValue >= badCaptureThreshold) return move; - // Losing capture, move it to the badCaptures[] array, note + // Losing capture, move it to the tail of the array, note // that move has now been already checked for legality. - assert(int(lastBadCapture - badCaptures) < 63); - lastBadCapture->move = move; - lastBadCapture->score = seeValue; - lastBadCapture++; + (--badCaptures)->move = move; + badCaptures->score = seeValue; } break; case PH_KILLERS: move = (curMove++)->move; if ( move != MOVE_NONE + && move_is_legal(pos, move, pinned) && move != ttMoves[0].move && move != ttMoves[1].move - && move_is_legal(pos, move, pinned) && !pos.move_is_capture(move)) return move; break; @@ -308,7 +313,7 @@ Move MovePicker::get_next_move() { // Sort negative scored moves only when we get there if (curMove == lastGoodNonCapture) - insertion_sort(lastGoodNonCapture, lastMove); + insertion_sort(lastGoodNonCapture, lastMove); move = (curMove++)->move; if ( move != ttMoves[0].move