From f8f5dcbb682830a66a37f68f3c192bbbfc84a33a Mon Sep 17 00:00:00 2001 From: lucasart Date: Mon, 16 Feb 2015 09:34:26 +0800 Subject: [PATCH] Compute checkers from scratch This micro-optimization only complicates the code and provides no benefit. Removing it is even a speedup on my machine (i7-3770k, linux, gcc 4.9.1): stat test master diff mean 2,403,118 2,390,904 12,214 stdev 12,043 10,620 3,677 speedup 0.51% P(speedup>0) 100.0% No functional change. --- src/position.cpp | 30 ++++-------------------------- src/position.h | 2 +- src/search.cpp | 8 ++++---- src/syzygy/tbprobe.cpp | 16 ++++++++-------- 4 files changed, 17 insertions(+), 39 deletions(-) diff --git a/src/position.cpp b/src/position.cpp index ef31d58d..eda26014 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -690,10 +690,10 @@ bool Position::gives_check(Move m, const CheckInfo& ci) const { void Position::do_move(Move m, StateInfo& newSt) { CheckInfo ci(*this); - do_move(m, newSt, ci, gives_check(m, ci)); + do_move(m, newSt, gives_check(m, ci)); } -void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) { +void Position::do_move(Move m, StateInfo& newSt, bool moveIsCheck) { assert(is_ok(m)); assert(&newSt != st); @@ -856,30 +856,8 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Update the key with the final value st->key = k; - // Update checkers bitboard: piece must be already moved due to attacks_from() - st->checkersBB = 0; - - if (moveIsCheck) - { - if (type_of(m) != NORMAL) - st->checkersBB = attackers_to(king_square(them)) & pieces(us); - else - { - // Direct checks - if (ci.checkSq[pt] & to) - st->checkersBB |= to; - - // Discovered checks - if (ci.dcCandidates && (ci.dcCandidates & from)) - { - if (pt != ROOK) - st->checkersBB |= attacks_from(king_square(them)) & pieces(us, QUEEN, ROOK); - - if (pt != BISHOP) - st->checkersBB |= attacks_from(king_square(them)) & pieces(us, QUEEN, BISHOP); - } - } - } + // Calculate checkers bitboard (if move is check) + st->checkersBB = moveIsCheck ? attackers_to(king_square(them)) & pieces(us) : 0; sideToMove = ~sideToMove; diff --git a/src/position.h b/src/position.h index 447872ab..14ce8099 100644 --- a/src/position.h +++ b/src/position.h @@ -145,7 +145,7 @@ public: // Doing and undoing moves void do_move(Move m, StateInfo& st); - void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool moveIsCheck); + void do_move(Move m, StateInfo& st, bool moveIsCheck); void undo_move(Move m); void do_null_move(StateInfo& st); void undo_null_move(); diff --git a/src/search.cpp b/src/search.cpp index eea52984..ffe36126 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -173,7 +173,7 @@ uint64_t Search::perft(Position& pos, Depth depth) { cnt = 1, nodes++; else { - pos.do_move(*it, st, ci, pos.gives_check(*it, ci)); + pos.do_move(*it, st, pos.gives_check(*it, ci)); cnt = leaf ? MoveList(pos).size() : perft(pos, depth - ONE_PLY); nodes += cnt; pos.undo_move(*it); @@ -702,7 +702,7 @@ namespace { if (pos.legal(move, ci.pinned)) { ss->currentMove = move; - pos.do_move(move, st, ci, pos.gives_check(move, ci)); + pos.do_move(move, st, pos.gives_check(move, ci)); value = -search(pos, ss+1, -rbeta, -rbeta+1, rdepth, !cutNode); pos.undo_move(move); if (value >= rbeta) @@ -894,7 +894,7 @@ moves_loop: // When in check and at SpNode search starts from here quietsSearched[quietCount++] = move; // Step 14. Make the move - pos.do_move(move, st, ci, givesCheck); + pos.do_move(move, st, givesCheck); // Step 15. Reduced depth search (LMR). If the move fails high it will be // re-searched at full depth. @@ -1255,7 +1255,7 @@ moves_loop: // When in check and at SpNode search starts from here ss->currentMove = move; // Make and search the move - pos.do_move(move, st, ci, givesCheck); + pos.do_move(move, st, givesCheck); value = givesCheck ? -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY) : -qsearch(pos, ss+1, -beta, -alpha, depth - ONE_PLY); pos.undo_move(move); diff --git a/src/syzygy/tbprobe.cpp b/src/syzygy/tbprobe.cpp index 0abd2b2e..17326970 100644 --- a/src/syzygy/tbprobe.cpp +++ b/src/syzygy/tbprobe.cpp @@ -367,7 +367,7 @@ static int probe_ab(Position& pos, int alpha, int beta, int *success) if (!pos.capture(capture) || type_of(capture) == ENPASSANT || !pos.legal(capture, ci.pinned)) continue; - pos.do_move(capture, st, ci, pos.gives_check(capture, ci)); + pos.do_move(capture, st, pos.gives_check(capture, ci)); v = -probe_ab(pos, -beta, -alpha, success); pos.undo_move(capture); if (*success == 0) return 0; @@ -430,7 +430,7 @@ int Tablebases::probe_wdl(Position& pos, int *success) if (type_of(capture) != ENPASSANT || !pos.legal(capture, ci.pinned)) continue; - pos.do_move(capture, st, ci, pos.gives_check(capture, ci)); + pos.do_move(capture, st, pos.gives_check(capture, ci)); int v0 = -probe_ab(pos, -2, 2, success); pos.undo_move(capture); if (*success == 0) return 0; @@ -493,7 +493,7 @@ static int probe_dtz_no_ep(Position& pos, int *success) if (type_of(pos.moved_piece(move)) != PAWN || pos.capture(move) || !pos.legal(move, ci.pinned)) continue; - pos.do_move(move, st, ci, pos.gives_check(move, ci)); + pos.do_move(move, st, pos.gives_check(move, ci)); int v = -probe_ab(pos, -2, -wdl + 1, success); pos.undo_move(move); if (*success == 0) return 0; @@ -515,7 +515,7 @@ static int probe_dtz_no_ep(Position& pos, int *success) if (pos.capture(move) || type_of(pos.moved_piece(move)) == PAWN || !pos.legal(move, ci.pinned)) continue; - pos.do_move(move, st, ci, pos.gives_check(move, ci)); + pos.do_move(move, st, pos.gives_check(move, ci)); int v = -Tablebases::probe_dtz(pos, success); pos.undo_move(move); if (*success == 0) return 0; @@ -534,7 +534,7 @@ static int probe_dtz_no_ep(Position& pos, int *success) Move move = moves->move; if (!pos.legal(move, ci.pinned)) continue; - pos.do_move(move, st, ci, pos.gives_check(move, ci)); + pos.do_move(move, st, pos.gives_check(move, ci)); if (st.rule50 == 0) { if (wdl == -2) v = -1; else { @@ -610,7 +610,7 @@ int Tablebases::probe_dtz(Position& pos, int *success) if (type_of(capture) != ENPASSANT || !pos.legal(capture, ci.pinned)) continue; - pos.do_move(capture, st, ci, pos.gives_check(capture, ci)); + pos.do_move(capture, st, pos.gives_check(capture, ci)); int v0 = -probe_ab(pos, -2, 2, success); pos.undo_move(capture); if (*success == 0) return 0; @@ -700,7 +700,7 @@ bool Tablebases::root_probe(Position& pos, Search::RootMoveVector& rootMoves, Va // Probe each move. for (size_t i = 0; i < rootMoves.size(); i++) { Move move = rootMoves[i].pv[0]; - pos.do_move(move, st, ci, pos.gives_check(move, ci)); + pos.do_move(move, st, pos.gives_check(move, ci)); int v = 0; if (pos.checkers() && dtz > 0) { ExtMove s[192]; @@ -810,7 +810,7 @@ bool Tablebases::root_probe_wdl(Position& pos, Search::RootMoveVector& rootMoves // Probe each move. for (size_t i = 0; i < rootMoves.size(); i++) { Move move = rootMoves[i].pv[0]; - pos.do_move(move, st, ci, pos.gives_check(move, ci)); + pos.do_move(move, st, pos.gives_check(move, ci)); int v = -Tablebases::probe_wdl(pos, &success); pos.undo_move(move); if (!success) return false; -- 2.39.2