From b05fbb3733df535a3fdf99e8d832001e57929699 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Mon, 9 Jan 2012 09:48:27 +0100 Subject: [PATCH] Unify PseudoAttacks arrays No functional change. Signed-off-by: Marco Costalba --- src/bitboard.cpp | 12 +++++------- src/bitboard.h | 4 +--- src/evaluate.cpp | 2 +- src/movegen.cpp | 37 ++++++++++++++++++------------------- src/position.cpp | 4 ++-- 5 files changed, 27 insertions(+), 32 deletions(-) diff --git a/src/bitboard.cpp b/src/bitboard.cpp index 57b24e2e..5c6b6e02 100644 --- a/src/bitboard.cpp +++ b/src/bitboard.cpp @@ -49,9 +49,7 @@ Bitboard SquaresInFrontMask[2][64]; Bitboard PassedPawnMask[2][64]; Bitboard AttackSpanMask[2][64]; -Bitboard BishopPseudoAttacks[64]; -Bitboard RookPseudoAttacks[64]; -Bitboard QueenPseudoAttacks[64]; +Bitboard PseudoAttacks[6][64]; uint8_t BitCount8Bit[256]; int SquareDistance[64][64]; @@ -227,14 +225,14 @@ void bitboards_init() { for (Square s = SQ_A1; s <= SQ_H8; s++) { - BishopPseudoAttacks[s] = bishop_attacks_bb(s, 0); - RookPseudoAttacks[s] = rook_attacks_bb(s, 0); - QueenPseudoAttacks[s] = queen_attacks_bb(s, 0); + PseudoAttacks[BISHOP][s] = bishop_attacks_bb(s, 0); + PseudoAttacks[ROOK][s] = rook_attacks_bb(s, 0); + PseudoAttacks[QUEEN][s] = queen_attacks_bb(s, 0); } for (Square s1 = SQ_A1; s1 <= SQ_H8; s1++) for (Square s2 = SQ_A1; s2 <= SQ_H8; s2++) - if (bit_is_set(QueenPseudoAttacks[s1], s2)) + if (bit_is_set(PseudoAttacks[QUEEN][s1], s2)) { Square delta = (s2 - s1) / square_distance(s1, s2); diff --git a/src/bitboard.h b/src/bitboard.h index cb4c9fad..ce198c22 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -49,9 +49,7 @@ extern int BShifts[64]; extern Bitboard BMasks[64]; extern Bitboard* BAttacks[64]; -extern Bitboard BishopPseudoAttacks[64]; -extern Bitboard RookPseudoAttacks[64]; -extern Bitboard QueenPseudoAttacks[64]; +extern Bitboard PseudoAttacks[6][64]; extern uint8_t BitCount8Bit[256]; diff --git a/src/evaluate.cpp b/src/evaluate.cpp index a48dc13e..3d2248a5 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -714,7 +714,7 @@ namespace { b = undefended & ei.attackedBy[Them][ROOK] & ~pos.pieces(Them); // Consider only squares where the enemy rook gives check - b &= RookPseudoAttacks[ksq]; + b &= PseudoAttacks[ROOK][ksq]; if (b) { diff --git a/src/movegen.cpp b/src/movegen.cpp index 865f9a82..c7c29a4e 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -262,9 +262,8 @@ namespace { do { - if ( (Pt == QUEEN && !(QueenPseudoAttacks[from] & checkSqs)) - || (Pt == ROOK && !(RookPseudoAttacks[from] & checkSqs)) - || (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs))) + if ( (Pt == BISHOP || Pt == ROOK || Pt == QUEEN) + && !(PseudoAttacks[Pt][from] & checkSqs)) continue; if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from)) @@ -399,7 +398,7 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) Bitboard b = pos.attacks_from(Piece(pt), from) & pos.empty_squares(); if (pt == KING) - b &= ~QueenPseudoAttacks[ci.ksq]; + b &= ~PseudoAttacks[QUEEN][ci.ksq]; SERIALIZE(b); } @@ -432,14 +431,13 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { int checkersCnt = 0; Color us = pos.side_to_move(); Square ksq = pos.king_square(us); - Bitboard checkers = pos.checkers(); Bitboard sliderAttacks = 0; + Bitboard checkers = pos.checkers(); - assert(pos.piece_on(ksq) == make_piece(us, KING)); assert(checkers); // Find squares attacked by slider checkers, we will remove them from the king - // evasions set so to skip known illegal moves and avoid to do legality check later. + // evasions so to skip known illegal moves avoiding useless legality check later. b = checkers; do { @@ -450,19 +448,20 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { switch (type_of(pos.piece_on(checksq))) { - case BISHOP: sliderAttacks |= BishopPseudoAttacks[checksq]; break; - case ROOK: sliderAttacks |= RookPseudoAttacks[checksq]; break; + case BISHOP: sliderAttacks |= PseudoAttacks[BISHOP][checksq]; break; + case ROOK: sliderAttacks |= PseudoAttacks[ROOK][checksq]; break; case QUEEN: - // If queen and king are far we can safely remove all the squares attacked - // in the other direction becuase are not reachable by the king anyway. - if (squares_between(ksq, checksq) || (RookPseudoAttacks[checksq] & (1ULL << ksq))) - sliderAttacks |= QueenPseudoAttacks[checksq]; - - // Otherwise, if king and queen are adjacent and on a diagonal line, we need to - // use real rook attacks to check if king is safe to move in the other direction. - // For example: king in B2, queen in A1 a knight in B1, and we can safely move to C1. + // If queen and king are far or not on a diagonal line we can safely + // remove all the squares attacked in the other direction becuase are + // not reachable by the king anyway. + if (squares_between(ksq, checksq) || !bit_is_set(PseudoAttacks[BISHOP][checksq], ksq)) + sliderAttacks |= PseudoAttacks[QUEEN][checksq]; + + // Otherwise we need to use real rook attacks to check if king is safe + // to move in the other direction. For example: king in B2, queen in A1 + // a knight in B1, and we can safely move to C1. else - sliderAttacks |= BishopPseudoAttacks[checksq] | pos.attacks_from(checksq); + sliderAttacks |= PseudoAttacks[BISHOP][checksq] | pos.attacks_from(checksq); default: break; @@ -478,7 +477,7 @@ MoveStack* generate(const Position& pos, MoveStack* mlist) { if (checkersCnt > 1) return mlist; - // Target for blocking evasions or captures of the checking piece + // Blocking evasions or captures of the checking piece target = squares_between(checksq, ksq) | checkers; mlist = generate_piece_moves(pos, mlist, us, target); diff --git a/src/position.cpp b/src/position.cpp index 1c966300..d5a28222 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -361,8 +361,8 @@ Bitboard Position::hidden_checkers() const { Square ksq = king_square(FindPinned ? sideToMove : flip(sideToMove)); // Pinners are sliders, that give check when candidate pinned is removed - pinners &= (pieces(ROOK, QUEEN) & RookPseudoAttacks[ksq]) - | (pieces(BISHOP, QUEEN) & BishopPseudoAttacks[ksq]); + pinners &= (pieces(ROOK, QUEEN) & PseudoAttacks[ROOK][ksq]) + | (pieces(BISHOP, QUEEN) & PseudoAttacks[BISHOP][ksq]); while (pinners) { -- 2.39.2