Enable Futility pruning in PV nodes

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 006834a7513c739df066ccc6fd72728a948fa88c..7e3f6ca58bd550d8cd525a69f0b0a618bfddc795 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -584,7 +584,7 @@ namespace {
     else if (ttHit)
     {
         // Never assume anything on values stored in TT
-        if ((ss->staticEval = eval = tte->eval_value()) == VALUE_NONE)
+        if ((ss->staticEval = eval = tte->eval()) == VALUE_NONE)
             eval = ss->staticEval = evaluate(pos);
 
         // Can ttValue be used as a better position evaluation?
@@ -632,7 +632,7 @@ namespace {
     }
 
     // Step 7. Futility pruning: child node (skipped when in check)
-    if (   !PvNode
+    if (   !RootNode
         &&  depth < 7 * ONE_PLY
         &&  eval - futility_margin(depth) >= beta
         &&  eval < VALUE_KNOWN_WIN  // Do not return unproven wins
@@ -650,7 +650,7 @@ namespace {
         assert(eval - beta >= 0);
 
         // Null move dynamic reduction based on depth and value
-        Depth R = (3 + depth / 4 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
+        Depth R = ((823 + 67 * depth) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         pos.do_null_move(st);
         (ss+1)->skipEarlyPruning = true;
@@ -829,9 +829,8 @@ moves_loop: // When in check and at SpNode search starts from here
       // Update the current move (this must be done after singular extension search)
       newDepth = depth - ONE_PLY + extension;
 
-      // Step 13. Pruning at shallow depth (exclude PV nodes)
-      if (   !PvNode
-          && !captureOrPromotion
+      // Step 13. Pruning at shallow depth
+      if (   !captureOrPromotion
           && !inCheck
           && !dangerous
           &&  bestValue > VALUE_MATED_IN_MAX_PLY)
@@ -906,7 +905,7 @@ moves_loop: // When in check and at SpNode search starts from here
           ss->reduction = reduction<PvNode>(improving, depth, moveCount);
 
           if (   (!PvNode && cutNode)
-              ||  History[pos.piece_on(to_sq(move))][to_sq(move)] < 0)
+              ||  History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO)
               ss->reduction += ONE_PLY;
 
           if (move == countermoves[0] || move == countermoves[1])
@@ -916,7 +915,7 @@ moves_loop: // When in check and at SpNode search starts from here
           if (   ss->reduction
               && type_of(move) == NORMAL
               && type_of(pos.piece_on(to_sq(move))) != PAWN
-              && pos.see(make_move(to_sq(move), from_sq(move))) < 0)
+              && pos.see(make_move(to_sq(move), from_sq(move))) < VALUE_ZERO)
               ss->reduction = std::max(DEPTH_ZERO, ss->reduction - ONE_PLY);
 
           Depth d = std::max(newDepth - ss->reduction, ONE_PLY);
@@ -1165,7 +1164,7 @@ moves_loop: // When in check and at SpNode search starts from here
         if (ttHit)
         {
             // Never assume anything on values stored in TT
-            if ((ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE)
+            if ((ss->staticEval = bestValue = tte->eval()) == VALUE_NONE)
                 ss->staticEval = bestValue = evaluate(pos);
 
             // Can ttValue be used as a better position evaluation?
@@ -1446,8 +1445,12 @@ moves_loop: // When in check and at SpNode search starts from here
         ss << "info depth " << d / ONE_PLY
            << " seldepth "  << selDepth
            << " multipv "   << i + 1
-           << " score "     << ((!tb && i == PVIdx) ? UCI::value(v, alpha, beta) : UCI::value(v))
-           << " nodes "     << pos.nodes_searched()
+           << " score "     << UCI::value(v);
+
+        if (!tb && i == PVIdx)
+              ss << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
+
+        ss << " nodes "     << pos.nodes_searched()
            << " nps "       << pos.nodes_searched() * 1000 / elapsed
            << " tbhits "    << TB::Hits
            << " time "      << elapsed