Merge branch 'official-stockfish:master' into master

AUTHORS

@@ -45,6 +45,7 @@ Bruno de Melo Costa (BM123499)
 Bruno Pellanda (pellanda)
 Bryan Cross (crossbr)
 candirufish
+Carlos Esparza Sánchez (ces42)
 Chess13234
 Chris Cain (ceebo)
 Ciekce

README.md

@@ -120,6 +120,11 @@ where the source code can be found) to generate the exact binary you are
 distributing. If you make any changes to the source code, these changes must
 also be made available under GPL v3.
 
+## Acknowledgements
+
+Stockfish uses neural networks trained on [data provided by the Leela Chess Zero
+project][lc0-data-link], which is made available under the [Open Database License][odbl-link] (ODbL).
+
 
 [authors-link]:       https://github.com/official-stockfish/Stockfish/blob/master/AUTHORS
 [build-link]:         https://github.com/official-stockfish/Stockfish/actions/workflows/stockfish.yml
@@ -144,6 +149,8 @@ also be made available under GPL v3.
 [wiki-uci-link]:      https://github.com/official-stockfish/Stockfish/wiki/UCI-&-Commands
 [wiki-usage-link]:    https://github.com/official-stockfish/Stockfish/wiki/Download-and-usage
 [worker-link]:        https://github.com/official-stockfish/fishtest/wiki/Running-the-worker
+[lc0-data-link]:      https://storage.lczero.org/files/training_data
+[odbl-link]:          https://opendatacommons.org/licenses/odbl/odbl-10.txt
 
 [build-badge]:        https://img.shields.io/github/actions/workflow/status/official-stockfish/Stockfish/stockfish.yml?branch=master&style=for-the-badge&label=stockfish&logo=github
 [commits-badge]:      https://img.shields.io/github/commits-since/official-stockfish/Stockfish/latest?style=for-the-badge

src/movepick.cpp

@@ -18,11 +18,9 @@
 
 #include "movepick.h"
 
-#include <algorithm>
 #include <array>
 #include <cassert>
 #include <limits>
-#include <utility>
 
 #include "bitboard.h"
 #include "position.h"
@@ -158,11 +156,11 @@ void MovePicker::score() {
             Square    to   = m.to_sq();
 
             // histories
-            m.value = (*mainHistory)[pos.side_to_move()][m.from_to()];
+            m.value = 2 * (*mainHistory)[pos.side_to_move()][m.from_to()];
             m.value += 2 * (*pawnHistory)[pawn_structure_index(pos)][pc][to];
-            m.value += 2 * (*continuationHistory[0])[pc][to];
+            m.value += (*continuationHistory[0])[pc][to];
             m.value += (*continuationHistory[1])[pc][to];
-            m.value += (*continuationHistory[2])[pc][to] / 3;
+            m.value += (*continuationHistory[2])[pc][to];
             m.value += (*continuationHistory[3])[pc][to];
             m.value += (*continuationHistory[5])[pc][to];
 
@@ -199,19 +197,13 @@ void MovePicker::score() {
 
 // Returns the next move satisfying a predicate function.
 // This never returns the TT move, as it was emitted before.
-template<MovePicker::PickType T, typename Pred>
+template<typename Pred>
 Move MovePicker::select(Pred filter) {
 
-    while (cur < endMoves)
-    {
-        if constexpr (T == Best)
-            std::swap(*cur, *std::max_element(cur, endMoves));
-
+    for (; cur < endMoves; ++cur)
         if (*cur != ttMove && filter())
             return *cur++;
 
-        cur++;
-    }
     return Move::none();
 }
 
@@ -245,7 +237,7 @@ Move MovePicker::next_move() {
         goto top;
 
     case GOOD_CAPTURE :
-        if (select<Next>([&]() {
+        if (select([&]() {
                 // Move losing capture to endBadCaptures to be tried later
                 return pos.see_ge(*cur, -cur->value / 18) ? true
                                                           : (*endBadCaptures++ = *cur, false);
@@ -269,7 +261,7 @@ Move MovePicker::next_move() {
         [[fallthrough]];
 
     case GOOD_QUIET :
-        if (!skipQuiets && select<Next>([]() { return true; }))
+        if (!skipQuiets && select([]() { return true; }))
         {
             if ((cur - 1)->value > -7998 || (cur - 1)->value <= quiet_threshold(depth))
                 return *(cur - 1);
@@ -286,7 +278,7 @@ Move MovePicker::next_move() {
         [[fallthrough]];
 
     case BAD_CAPTURE :
-        if (select<Next>([]() { return true; }))
+        if (select([]() { return true; }))
             return *(cur - 1);
 
         // Prepare the pointers to loop over the bad quiets
@@ -298,7 +290,7 @@ Move MovePicker::next_move() {
 
     case BAD_QUIET :
         if (!skipQuiets)
-            return select<Next>([]() { return true; });
+            return select([]() { return true; });
 
         return Move::none();
 
@@ -307,17 +299,16 @@ Move MovePicker::next_move() {
         endMoves = generate<EVASIONS>(pos, cur);
 
         score<EVASIONS>();
+        partial_insertion_sort(cur, endMoves, std::numeric_limits<int>::min());
         ++stage;
         [[fallthrough]];
 
     case EVASION :
-        return select<Best>([]() { return true; });
+    case QCAPTURE :
+        return select([]() { return true; });
 
     case PROBCUT :
-        return select<Next>([&]() { return pos.see_ge(*cur, threshold); });
-
-    case QCAPTURE :
-        return select<Next>([]() { return true; });
+        return select([&]() { return pos.see_ge(*cur, threshold); });
     }
 
     assert(false);

src/movepick.h

@@ -35,11 +35,6 @@ class Position;
 // a cut-off first.
 class MovePicker {
 
-    enum PickType {
-        Next,
-        Best
-    };
-
    public:
     MovePicker(const MovePicker&)            = delete;
     MovePicker& operator=(const MovePicker&) = delete;
@@ -57,7 +52,7 @@ class MovePicker {
     void skip_quiet_moves();
 
    private:
-    template<PickType T, typename Pred>
+    template<typename Pred>
     Move select(Pred);
     template<GenType>
     void     score();

src/nnue/nnue_misc.cpp

@@ -126,7 +126,7 @@ trace(Position& pos, const Eval::NNUE::Networks& networks, Eval::NNUE::Accumulat
         board[y][x] = board[y][x + 8] = board[y + 3][x + 8] = board[y + 3][x] = '+';
         if (pc != NO_PIECE)
             board[y + 1][x + 4] = PieceToChar[pc];
-        if (value != VALUE_NONE)
+        if (is_valid(value))
             format_cp_compact(value, &board[y + 2][x + 2], pos);
     };
 

src/position.cpp

@@ -360,7 +360,7 @@ void Position::set_state() const {
             {
                 st->nonPawnMaterial[color_of(pc)] += PieceValue[pc];
 
-                if (type_of(pc) == QUEEN || type_of(pc) == ROOK)
+                if (type_of(pc) >= ROOK)
                     st->majorPieceKey ^= Zobrist::psq[pc][s];
 
                 else
@@ -759,7 +759,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
             st->nonPawnMaterial[them] -= PieceValue[captured];
             st->nonPawnKey[them] ^= Zobrist::psq[captured][capsq];
 
-            if (type_of(captured) == QUEEN || type_of(captured) == ROOK)
+            if (type_of(captured) >= ROOK)
                 st->majorPieceKey ^= Zobrist::psq[captured][capsq];
 
             else
@@ -844,7 +844,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
             st->materialKey ^=
               Zobrist::psq[promotion][pieceCount[promotion] - 1] ^ Zobrist::psq[pc][pieceCount[pc]];
 
-            if (promotionType == QUEEN || promotionType == ROOK)
+            if (promotionType >= ROOK)
                 st->majorPieceKey ^= Zobrist::psq[promotion][to];
 
             else
@@ -871,7 +871,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) {
             st->minorPieceKey ^= Zobrist::psq[pc][from] ^ Zobrist::psq[pc][to];
         }
 
-        else if (type_of(pc) == QUEEN || type_of(pc) == ROOK)
+        else if (type_of(pc) >= ROOK)
             st->majorPieceKey ^= Zobrist::psq[pc][from] ^ Zobrist::psq[pc][to];
 
         else

src/score.cpp

@@ -29,7 +29,7 @@ namespace Stockfish {
 Score::Score(Value v, const Position& pos) {
     assert(-VALUE_INFINITE < v && v < VALUE_INFINITE);
 
-    if (std::abs(v) < VALUE_TB_WIN_IN_MAX_PLY)
+    if (!is_decisive(v))
     {
         score = InternalUnits{UCIEngine::to_cp(v, pos)};
     }