When we know already no captures are possible in a given
position.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
#include <cassert>
#include "history.h"
#include <cassert>
#include "history.h"
#include "movegen.h"
#include "movepick.h"
#include "search.h"
#include "movegen.h"
#include "movepick.h"
#include "search.h"
int MainSearchPhaseIndex;
int EvasionsPhaseIndex;
int QsearchWithChecksPhaseIndex;
int MainSearchPhaseIndex;
int EvasionsPhaseIndex;
int QsearchWithChecksPhaseIndex;
+ int QsearchNoCapturesPhaseIndex;
int QsearchWithoutChecksPhaseIndex;
int QsearchWithoutChecksPhaseIndex;
/// search captures, promotions and some checks) and about how important good
/// move ordering is at the current node.
/// search captures, promotions and some checks) and about how important good
/// move ordering is at the current node.
-MovePicker::MovePicker(const Position& p, bool pvnode, Move ttm, Move mk,
- Move k1, Move k2, Depth d) : pos(p) {
- pvNode = pvnode;
+MovePicker::MovePicker(const Position& p, bool pv, Move ttm,
+ Move mk, Move k1, Move k2, Depth d, EvalInfo* ei) : pos(p) {
+ pvNode = pv;
ttMove = ttm;
mateKiller = (mk == ttm)? MOVE_NONE : mk;
killer1 = k1;
ttMove = ttm;
mateKiller = (mk == ttm)? MOVE_NONE : mk;
killer1 = k1;
movesPicked = 0;
numOfMoves = 0;
numOfBadCaptures = 0;
movesPicked = 0;
numOfMoves = 0;
numOfBadCaptures = 0;
- dc = p.discovered_check_candidates(p.side_to_move());
+
+ // With EvalInfo we are able to know how many captures are possible before
+ // generating them. So avoid generating them in case we know are zero.
+ Color us = pos.side_to_move();
+ Color them = opposite_color(us);
+ bool noAttacks = ei && (ei->attackedBy[us][0] & pos.pieces_of_color(them)) == 0;
+ bool noCaptures = noAttacks && (pos.ep_square() == SQ_NONE) && !pos.has_pawn_on_7th(us);
- phaseIndex = EvasionsPhaseIndex;
+ phaseIndex = EvasionsPhaseIndex;
else if (depth > Depth(0))
else if (depth > Depth(0))
- phaseIndex = MainSearchPhaseIndex;
+ phaseIndex = MainSearchPhaseIndex;
else if (depth == Depth(0))
else if (depth == Depth(0))
- phaseIndex = QsearchWithChecksPhaseIndex;
+ phaseIndex = (noCaptures ? QsearchNoCapturesPhaseIndex : QsearchWithChecksPhaseIndex);
- phaseIndex = QsearchWithoutChecksPhaseIndex;
+ phaseIndex = (noCaptures ? NoMovesPhaseIndex : QsearchWithoutChecksPhaseIndex);
+
+ dc = p.discovered_check_candidates(us);
pinned = p.pinned_pieces(p.side_to_move());
finished = false;
pinned = p.pinned_pieces(p.side_to_move());
finished = false;
/// MovePicker::init_phase_table() initializes the PhaseTable[],
/// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex
/// MovePicker::init_phase_table() initializes the PhaseTable[],
/// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex
-/// and QsearchWithoutChecksPhaseIndex variables. It is only called once
-/// during program startup, and never again while the program is running.
+/// QsearchNoCapturesPhaseIndex, QsearchWithoutChecksPhaseIndex and
+/// NoMovesPhaseIndex variables. It is only called once during program
+/// startup, and never again while the program is running.
void MovePicker::init_phase_table() {
void MovePicker::init_phase_table() {
PhaseTable[i++] = PH_QCHECKS;
PhaseTable[i++] = PH_STOP;
PhaseTable[i++] = PH_QCHECKS;
PhaseTable[i++] = PH_STOP;
+ // Quiescence search with checks only and no captures
+ QsearchNoCapturesPhaseIndex = i - 1;
+ PhaseTable[i++] = PH_QCHECKS;
+ PhaseTable[i++] = PH_STOP;
+
// Quiescence search without checks
QsearchWithoutChecksPhaseIndex = i - 1;
PhaseTable[i++] = PH_QCAPTURES;
PhaseTable[i++] = PH_STOP;
// Quiescence search without checks
QsearchWithoutChecksPhaseIndex = i - 1;
PhaseTable[i++] = PH_QCAPTURES;
PhaseTable[i++] = PH_STOP;
+
+ // Do not generate any move
+ NoMovesPhaseIndex = i - 1;
+ PhaseTable[i++] = PH_STOP;
/// MovePicker is a class which is used to pick one legal move at a time from
/// the current position. It is initialized with a Position object and a few
/// moves we have reason to believe are good. The most important method is
/// MovePicker is a class which is used to pick one legal move at a time from
/// the current position. It is initialized with a Position object and a few
/// moves we have reason to believe are good. The most important method is
- MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, Depth d);
+ MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, Depth d, EvalInfo* ei = NULL);
Move get_next_move();
Move get_next_move(Lock &lock);
int number_of_moves() const;
Move get_next_move();
Move get_next_move(Lock &lock);
int number_of_moves() const;
if (m != MOVE_NONE)
{
Position p(*this);
if (m != MOVE_NONE)
{
Position p(*this);
- std::cout << "Move is: " << move_to_san(p, m) << std::endl;
+ std::string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : "");
+ std::cout << "Move is: " << col << move_to_san(p, m) << std::endl;
}
for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
}
for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
// Number of pieces of each color and type
int piece_count(Color c, PieceType pt) const;
// Number of pieces of each color and type
int piece_count(Color c, PieceType pt) const;
- // The en passant square:
+ // The en passant square
Square ep_square() const;
// Current king position for each color
Square king_square(Color c) const;
Square ep_square() const;
// Current king position for each color
Square king_square(Color c) const;
bool can_castle_kingside(Color c) const;
bool can_castle_queenside(Color c) const;
bool can_castle(Color c) const;
bool can_castle_kingside(Color c) const;
bool can_castle_queenside(Color c) const;
bool can_castle(Color c) const;
// to search the moves. Because the depth is <= 0 here, only captures,
// queen promotions and checks (only if depth == 0) will be generated.
MovePicker mp = MovePicker(pos, false, MOVE_NONE, MOVE_NONE, MOVE_NONE,
// to search the moves. Because the depth is <= 0 here, only captures,
// queen promotions and checks (only if depth == 0) will be generated.
MovePicker mp = MovePicker(pos, false, MOVE_NONE, MOVE_NONE, MOVE_NONE,
+ MOVE_NONE, depth, &ei);
Move move;
int moveCount = 0;
Bitboard dcCandidates = mp.discovered_check_candidates();
Move move;
int moveCount = 0;
Bitboard dcCandidates = mp.discovered_check_candidates();