Merge branch 'official-stockfish:master' into master

src/bitboard.cpp

@@ -124,8 +124,14 @@ Bitboard sliding_attack(PieceType pt, Square sq, Bitboard occupied) {
     for (Direction d : (pt == ROOK ? RookDirections : BishopDirections))
     {
         Square s = sq;
-        while (safe_destination(s, d) && !(occupied & s))
+        while (safe_destination(s, d))
+        {
             attacks |= (s += d);
+            if (occupied & s)
+            {
+                break;
+            }
+        }
     }
 
     return attacks;

src/evaluate.cpp

@@ -44,6 +44,10 @@ int Eval::simple_eval(const Position& pos, Color c) {
          + (pos.non_pawn_material(c) - pos.non_pawn_material(~c));
 }
 
+bool Eval::use_smallnet(const Position& pos) {
+    int simpleEval = simple_eval(pos, pos.side_to_move());
+    return std::abs(simpleEval) > 1126 + 6 * pos.count<PAWN>();
+}
 
 // Evaluate is the evaluator for the outer world. It returns a static evaluation
 // of the position from the point of view of the side to move.
@@ -55,7 +59,7 @@ Value Eval::evaluate(const Eval::NNUE::Networks&    networks,
     assert(!pos.checkers());
 
     int  simpleEval = simple_eval(pos, pos.side_to_move());
-    bool smallNet   = std::abs(simpleEval) > SmallNetThreshold + 6 * pos.count<PAWN>();
+    bool smallNet   = use_smallnet(pos);
     int  nnueComplexity;
     int  v;
 
@@ -68,23 +72,23 @@ Value Eval::evaluate(const Eval::NNUE::Networks&    networks,
         smallNet = false;
     }
 
-    const auto adjustEval = [&](int pawnCountMul, int shufflingConstant) {
+    const auto adjustEval = [&](int shufflingConstant) {
         // Blend optimism and eval with nnue complexity and material imbalance
         optimism += optimism * (nnueComplexity + std::abs(simpleEval - nnue)) / 584;
         nnue -= nnue * (nnueComplexity * 5 / 3) / 32395;
 
         int npm = pos.non_pawn_material() / 64;
-        v = (nnue * (npm + 943 + pawnCountMul * pos.count<PAWN>()) + optimism * (npm + 140)) / 1058;
+        v       = (nnue * (npm + 943 + 11 * pos.count<PAWN>()) + optimism * (npm + 140)) / 1058;
 
         // Damp down the evaluation linearly when shuffling
         int shuffling = pos.rule50_count();
         v             = v * (shufflingConstant - shuffling) / 207;
     };
 
     if (!smallNet)
-        adjustEval(11, 178);
+        adjustEval(178);
     else
-        adjustEval(9, 206);
+        adjustEval(206);
 
     // Guarantee evaluation does not hit the tablebase range
     v = std::clamp(v, VALUE_TB_LOSS_IN_MAX_PLY + 1, VALUE_TB_WIN_IN_MAX_PLY - 1);

src/evaluate.h

@@ -29,13 +29,11 @@ class Position;
 
 namespace Eval {
 
-constexpr inline int SmallNetThreshold = 1126;
-
 // The default net name MUST follow the format nn-[SHA256 first 12 digits].nnue
 // for the build process (profile-build and fishtest) to work. Do not change the
 // name of the macro or the location where this macro is defined, as it is used
 // in the Makefile/Fishtest.
-#define EvalFileDefaultNameBig "nn-ae6a388e4a1a.nnue"
+#define EvalFileDefaultNameBig "nn-c721dfca8cd3.nnue"
 #define EvalFileDefaultNameSmall "nn-baff1ede1f90.nnue"
 
 namespace NNUE {
@@ -46,6 +44,7 @@ struct AccumulatorCaches;
 std::string trace(Position& pos, const Eval::NNUE::Networks& networks);
 
 int   simple_eval(const Position& pos, Color c);
+bool  use_smallnet(const Position& pos);
 Value evaluate(const NNUE::Networks&          networks,
                const Position&                pos,
                Eval::NNUE::AccumulatorCaches& caches,

src/nnue/nnue_misc.cpp

@@ -45,9 +45,7 @@ constexpr std::string_view PieceToChar(" PNBRQK  pnbrqk");
 void hint_common_parent_position(const Position&    pos,
                                  const Networks&    networks,
                                  AccumulatorCaches& caches) {
-
-    int simpleEvalAbs = std::abs(simple_eval(pos, pos.side_to_move()));
-    if (simpleEvalAbs > Eval::SmallNetThreshold + 6 * pos.count<PAWN>())
+    if (Eval::use_smallnet(pos))
         networks.small.hint_common_access(pos, &caches.small);
     else
         networks.big.hint_common_access(pos, &caches.big);

src/search.cpp

@@ -787,7 +787,7 @@ Value Search::Worker::search(
         assert(eval - beta >= 0);
 
         // Null move dynamic reduction based on depth and eval
-        Depth R = std::min(int(eval - beta) / 144, 6) + depth / 3 + 4;
+        Depth R = std::min(int(eval - beta) / 144, 6) + depth / 3 + 5;
 
         ss->currentMove         = Move::null();
         ss->continuationHistory = &thisThread->continuationHistory[0][0][NO_PIECE][0];
@@ -1053,11 +1053,9 @@ Value Search::Worker::search(
                     int doubleMargin = 285 * PvNode - 228 * !ttCapture;
                     int tripleMargin =
                       121 + 238 * PvNode - 259 * !ttCapture + 117 * (ss->ttPv || !ttCapture);
-                    int quadMargin = 471 + 343 * PvNode - 281 * !ttCapture + 217 * ss->ttPv;
 
                     extension = 1 + (value < singularBeta - doubleMargin)
-                              + (value < singularBeta - tripleMargin)
-                              + (value < singularBeta - quadMargin);
+                              + (value < singularBeta - tripleMargin);
 
                     depth += ((!PvNode) && (depth < 14));
                 }

src/tt.cpp

@@ -35,7 +35,7 @@ namespace Stockfish {
 void TTEntry::save(
   Key k, Value v, bool pv, Bound b, Depth d, Move m, Value ev, uint8_t generation8) {
 
-    // Preserve any existing move for the same position
+    // Preserve the old ttmove if we don't have a new one
     if (m || uint16_t(k) != key16)
         move16 = m;