Simplify saving a TT entry.

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 2185a3214fc59dd651c3e6639669cbcead83d7df..3f89c0400c24d2f54e9aee6fc52eac7a5f5cd56c 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -71,16 +71,6 @@ namespace {
     return Value((175 - 50 * improving) * d / ONE_PLY);
   }
 
-  // Margin for pruning capturing moves: almost linear in depth
-  constexpr int CapturePruneMargin[] = { 0,
-                                         1 * PawnValueEg * 1055 / 1000,
-                                         2 * PawnValueEg * 1042 / 1000,
-                                         3 * PawnValueEg * 963  / 1000,
-                                         4 * PawnValueEg * 1038 / 1000,
-                                         5 * PawnValueEg * 950  / 1000,
-                                         6 * PawnValueEg * 930  / 1000
-                                       };
-
   // Futility and reductions lookup tables, initialized at startup
   int FutilityMoveCounts[2][16]; // [improving][depth]
   int Reductions[2][2][64][64];  // [pv][improving][depth][moveNumber]
@@ -296,6 +286,7 @@ void Thread::search() {
   MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
   double timeReduction = 1.0;
   Color us = rootPos.side_to_move();
+  bool failedLow;
 
   std::memset(ss-4, 0, 7 * sizeof(Stack));
   for (int i = 4; i > 0; i--)
@@ -305,7 +296,7 @@ void Thread::search() {
   beta = VALUE_INFINITE;
 
   if (mainThread)
-      mainThread->bestMoveChanges = 0, mainThread->failedLow = false;
+      mainThread->bestMoveChanges = 0, failedLow = false;
 
   size_t multiPV = Options["MultiPV"];
   Skill skill(Options["Skill Level"]);
@@ -346,7 +337,7 @@ void Thread::search() {
 
       // Age out PV variability metric
       if (mainThread)
-          mainThread->bestMoveChanges *= 0.517, mainThread->failedLow = false;
+          mainThread->bestMoveChanges *= 0.517, failedLow = false;
 
       // Save the last iteration's scores before first PV line is searched and
       // all the move scores except the (new) PV are set to -VALUE_INFINITE.
@@ -423,7 +414,7 @@ void Thread::search() {
 
                   if (mainThread)
                   {
-                      mainThread->failedLow = true;
+                      failedLow = true;
                       Threads.stopOnPonderhit = false;
                   }
               }
@@ -471,7 +462,7 @@ void Thread::search() {
           && !Threads.stop
           && !Threads.stopOnPonderhit)
           {
-              const int F[] = { mainThread->failedLow,
+              const int F[] = { failedLow,
                                 bestValue - mainThread->previousScore };
 
               int improvingFactor = std::max(246, std::min(832, 306 + 119 * F[0] - 6 * F[1]));
@@ -522,7 +513,7 @@ namespace {
     constexpr bool PvNode = NT == PV;
     const bool rootNode = PvNode && ss->ply == 0;
 
-    // Check if we have an upcoming move which draws by repetition, or 
+    // Check if we have an upcoming move which draws by repetition, or
     // if the opponent had an alternative move earlier to this position.
     if (   pos.rule50_count() >= 3
         && alpha < VALUE_DRAW
@@ -679,7 +670,7 @@ namespace {
                 {
                     tte->save(posKey, value_to_tt(value, ss->ply), b,
                               std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY),
-                              MOVE_NONE, VALUE_NONE, TT.generation());
+                              MOVE_NONE, VALUE_NONE);
 
                     return value;
                 }
@@ -720,7 +711,7 @@ namespace {
                                          : -(ss-1)->staticEval + 2 * Eval::Tempo;
 
         tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE,
-                  ss->staticEval, TT.generation());
+                  ss->staticEval);
     }
 
     // Step 7. Razoring (~2 Elo)
@@ -956,13 +947,11 @@ moves_loop: // When in check, search starts from here
                   continue;
 
               // Prune moves with negative SEE (~10 Elo)
-              if (   lmrDepth < 8
-                  && !pos.see_ge(move, Value(-35 * lmrDepth * lmrDepth)))
+              if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth)))
                   continue;
           }
-          else if (    depth < 7 * ONE_PLY // (~20 Elo)
-                   && !extension
-                   && !pos.see_ge(move, -Value(CapturePruneMargin[depth / ONE_PLY])))
+          else if (   !extension // (~20 Elo)
+                   && !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY)))
                   continue;
       }
 
@@ -1164,10 +1153,10 @@ moves_loop: // When in check, search starts from here
     {
         // Quiet best move: update move sorting heuristics
         if (!pos.capture_or_promotion(bestMove))
-            update_quiet_stats(pos, ss, bestMove, quietsSearched, quietCount, stat_bonus(depth));
+            update_quiet_stats(pos, ss, bestMove, quietsSearched, quietCount,
+                               stat_bonus(depth + (bestValue > beta + PawnValueMg ? ONE_PLY : DEPTH_ZERO)));
         else
-            update_capture_stats(pos, bestMove, capturesSearched, captureCount,
-                                 stat_bonus(depth + (bestValue > beta + KnightValueMg ? ONE_PLY : DEPTH_ZERO)));
+            update_capture_stats(pos, bestMove, capturesSearched, captureCount, stat_bonus(depth + ONE_PLY));
 
         // Extra penalty for a quiet TT move in previous ply when it gets refuted
         if ((ss-1)->moveCount == 1 && !pos.captured_piece())
@@ -1186,7 +1175,7 @@ moves_loop: // When in check, search starts from here
         tte->save(posKey, value_to_tt(bestValue, ss->ply),
                   bestValue >= beta ? BOUND_LOWER :
                   PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER,
-                  depth, bestMove, ss->staticEval, TT.generation());
+                  depth, bestMove, ss->staticEval);
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
 
@@ -1283,7 +1272,7 @@ moves_loop: // When in check, search starts from here
         {
             if (!ttHit)
                 tte->save(posKey, value_to_tt(bestValue, ss->ply), BOUND_LOWER,
-                          DEPTH_NONE, MOVE_NONE, ss->staticEval, TT.generation());
+                          DEPTH_NONE, MOVE_NONE, ss->staticEval);
 
             return bestValue;
         }
@@ -1382,7 +1371,7 @@ moves_loop: // When in check, search starts from here
               else // Fail high
               {
                   tte->save(posKey, value_to_tt(value, ss->ply), BOUND_LOWER,
-                            ttDepth, move, ss->staticEval, TT.generation());
+                            ttDepth, move, ss->staticEval);
 
                   return value;
               }
@@ -1397,7 +1386,7 @@ moves_loop: // When in check, search starts from here
 
     tte->save(posKey, value_to_tt(bestValue, ss->ply),
               PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER,
-              ttDepth, bestMove, ss->staticEval, TT.generation());
+              ttDepth, bestMove, ss->staticEval);
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);