X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=14121d47af67dd234c5f04134328a9c895654717;hp=ada03fbcf4b1076b38d5aca3583d5bf5b60be2f7;hb=d39bc2efa197ba2fd55b68eced1c60bcfe2facc1;hpb=ec49e676a70435472cb70a9cf0c0376dfab31af4
diff --git a/src/position.cpp b/src/position.cpp
index ada03fbc..14121d47 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -18,6 +18,7 @@
along with this program. If not, see .
*/
+#include
#include
#include // For offsetof()
#include // For std::memset, std::memcmp
@@ -340,8 +341,8 @@ void Position::set_castling_right(Color c, Square rfrom) {
Square kto = relative_square(c, cs == KING_SIDE ? SQ_G1 : SQ_C1);
Square rto = relative_square(c, cs == KING_SIDE ? SQ_F1 : SQ_D1);
- castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto)
- & ~(square_bb(kfrom) | rfrom);
+ castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto)
+ & ~(square_bb(kfrom) | rfrom);
}
@@ -382,6 +383,12 @@ void Position::set_state(StateInfo* si) const {
Square s = pop_lsb(&b);
Piece pc = piece_on(s);
si->key ^= Zobrist::psq[pc][s];
+
+ if (type_of(pc) == PAWN)
+ si->pawnKey ^= Zobrist::psq[pc][s];
+
+ else if (type_of(pc) != KING)
+ si->nonPawnMaterial[color_of(pc)] += PieceValue[MG][pc];
}
if (si->epSquare != SQ_NONE)
@@ -392,20 +399,9 @@ void Position::set_state(StateInfo* si) const {
si->key ^= Zobrist::castling[si->castlingRights];
- for (Bitboard b = pieces(PAWN); b; )
- {
- Square s = pop_lsb(&b);
- si->pawnKey ^= Zobrist::psq[piece_on(s)][s];
- }
-
for (Piece pc : Pieces)
- {
- if (type_of(pc) != PAWN && type_of(pc) != KING)
- si->nonPawnMaterial[color_of(pc)] += pieceCount[pc] * PieceValue[MG][pc];
-
for (int cnt = 0; cnt < pieceCount[pc]; ++cnt)
si->materialKey ^= Zobrist::psq[pc][cnt];
- }
}
@@ -495,7 +491,7 @@ Bitboard Position::slider_blockers(Bitboard sliders, Square s, Bitboard& pinners
// Snipers are sliders that attack 's' when a piece and other snipers are removed
Bitboard snipers = ( (PseudoAttacks[ ROOK][s] & pieces(QUEEN, ROOK))
| (PseudoAttacks[BISHOP][s] & pieces(QUEEN, BISHOP))) & sliders;
- Bitboard occupancy = pieces() & ~snipers;
+ Bitboard occupancy = pieces() ^ snipers;
while (snipers)
{
@@ -859,7 +855,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
// Update pawn hash key and prefetch access to pawnsTable
st->pawnKey ^= Zobrist::psq[pc][from] ^ Zobrist::psq[pc][to];
- prefetch2(thisThread->pawnsTable[st->pawnKey]);
// Reset rule 50 draw counter
st->rule50 = 0;
@@ -879,6 +874,25 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
// Update king attacks used for fast check detection
set_check_info(st);
+ // Calculate the repetition info. It is the ply distance from the previous
+ // occurrence of the same position, negative in the 3-fold case, or zero
+ // if the position was not repeated.
+ st->repetition = 0;
+ int end = std::min(st->rule50, st->pliesFromNull);
+ if (end >= 4)
+ {
+ StateInfo* stp = st->previous->previous;
+ for (int i=4; i <= end; i += 2)
+ {
+ stp = stp->previous->previous;
+ if (stp->key == st->key)
+ {
+ st->repetition = stp->repetition ? -i : i;
+ break;
+ }
+ }
+ }
+
assert(pos_is_ok());
}
@@ -994,6 +1008,8 @@ void Position::do_null_move(StateInfo& newSt) {
set_check_info(st);
+ st->repetition = 0;
+
assert(pos_is_ok());
}
@@ -1117,24 +1133,10 @@ bool Position::is_draw(int ply) const {
if (st->rule50 > 99 && (!checkers() || MoveList(*this).size()))
return true;
- int end = std::min(st->rule50, st->pliesFromNull);
-
- if (end < 4)
- return false;
-
- StateInfo* stp = st->previous->previous;
- int cnt = 0;
-
- for (int i = 4; i <= end; i += 2)
- {
- stp = stp->previous->previous;
-
- // Return a draw score if a position repeats once earlier but strictly
- // after the root, or repeats twice before or at the root.
- if ( stp->key == st->key
- && ++cnt + (ply > i) == 2)
- return true;
- }
+ // Return a draw score if a position repeats once earlier but strictly
+ // after the root, or repeats twice before or at the root.
+ if (st->repetition && st->repetition < ply)
+ return true;
return false;
}
@@ -1146,26 +1148,15 @@ bool Position::is_draw(int ply) const {
bool Position::has_repeated() const {
StateInfo* stc = st;
- while (true)
+ int end = std::min(st->rule50, st->pliesFromNull);
+ while (end-- >= 4)
{
- int i = 4, end = std::min(stc->rule50, stc->pliesFromNull);
-
- if (end < i)
- return false;
-
- StateInfo* stp = stc->previous->previous;
-
- do {
- stp = stp->previous->previous;
-
- if (stp->key == stc->key)
- return true;
-
- i += 2;
- } while (i <= end);
+ if (stc->repetition)
+ return true;
stc = stc->previous;
}
+ return false;
}
@@ -1198,22 +1189,19 @@ bool Position::has_game_cycle(int ply) const {
if (!(between_bb(s1, s2) & pieces()))
{
- // In the cuckoo table, both moves Rc1c5 and Rc5c1 are stored in the same
- // location. We select the legal one by reversing the move variable if necessary.
- if (empty(s1))
- move = make_move(s2, s1);
-
if (ply > i)
return true;
+ // For nodes before or at the root, check that the move is a
+ // repetition rather than a move to the current position.
+ // In the cuckoo table, both moves Rc1c5 and Rc5c1 are stored in
+ // the same location, so we have to select which square to check.
+ if (color_of(piece_on(empty(s1) ? s2 : s1)) != side_to_move())
+ continue;
+
// For repetitions before or at the root, require one more
- StateInfo* next_stp = stp;
- for (int k = i + 2; k <= end; k += 2)
- {
- next_stp = next_stp->previous->previous;
- if (next_stp->key == stp->key)
- return true;
- }
+ if (stp->repetition)
+ return true;
}
}
}