X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=fca3d2c9dbc431a89f1acdf9e764fa0f18ada6fd;hp=10aa196add95d87944db24863eb1cbd5c764010e;hb=038235ba3541087e2db969a0a4bdfd5fc2a42b44;hpb=4fa5dd4db55ba9fde841120fc8fbcd99f6540eb4

diff --git a/src/search.cpp b/src/search.cpp
index 10aa196a..fca3d2c9 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1,13 +1,14 @@
 /*
-  Glaurung, a UCI chess playing engine.
-  Copyright (C) 2004-2008 Tord Romstad
+  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+  Copyright (C) 2008 Marco Costalba
 
-  Glaurung is free software: you can redistribute it and/or modify
+  Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
-  Glaurung is distributed in the hope that it will be useful,
+  Stockfish is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
@@ -152,6 +153,12 @@ namespace {
   Depth RazorDepth = 4*OnePly;
   Value RazorMargin = Value(0x300);
 
+  // Last seconds noise filtering (LSN)
+  bool UseLSNFiltering = false;
+  bool looseOnTime = false;
+  int LSNTime = 4 * 1000; // In milliseconds
+  Value LSNValue = Value(0x200);
+
   // Extensions.  Array index 0 is used at non-PV nodes, index 1 at PV nodes.
   Depth CheckExtension[2] = {OnePly, OnePly};
   Depth SingleReplyExtension[2] = {OnePly / 2, OnePly / 2};
@@ -220,7 +227,7 @@ namespace {
 
   /// Functions
 
-  void id_loop(const Position &pos, Move searchMoves[]);
+  Value id_loop(const Position &pos, Move searchMoves[]);
   Value root_search(Position &pos, SearchStack ss[], RootMoveList &rml);
   Value search_pv(Position &pos, SearchStack ss[], Value alpha, Value beta,
                   Depth depth, int ply, int threadID);
@@ -295,7 +302,7 @@ History H;  // Should be made local?
 //// Functions
 ////
 
-/// think() is the external interface to Glaurung's search, and is called when
+/// think() is the external interface to Stockfish's search, and is called when
 /// the program receives the UCI 'go' command.  It initializes various
 /// search-related global variables, and calls root_search()
 
@@ -394,6 +401,10 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move,
   RazorDepth = (get_option_value_int("Maximum Razoring Depth") + 1) * OnePly;
   RazorMargin = value_from_centipawns(get_option_value_int("Razoring Margin"));
 
+  UseLSNFiltering = get_option_value_bool("LSN filtering");
+  LSNTime = get_option_value_int("LSN Time Margin (sec)") * 1000;
+  LSNValue = value_from_centipawns(get_option_value_int("LSN Value Margin"));
+
   MinimumSplitDepth = get_option_value_int("Minimum Split Depth") * OnePly;
   MaxThreadsPerSplitPoint =
     get_option_value_int("Maximum Number of Threads per Split Point");
@@ -468,7 +479,21 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move,
 
   // We're ready to start thinking.  Call the iterative deepening loop
   // function:
-  id_loop(pos, searchMoves);
+  if (!looseOnTime)
+  {
+      Value v = id_loop(pos, searchMoves);
+      looseOnTime = (   UseLSNFiltering
+                     && myTime < LSNTime
+                     && myIncrement == 0
+                     && v < -LSNValue);
+  }
+  else
+  {
+      looseOnTime = false; // reset for next match
+      while (SearchStartTime + myTime + 1000 > get_system_time())
+          ; // wait here
+      id_loop(pos, searchMoves); // to fail gracefully
+  }
 
   if(UseLogFile)
     LogFile.close();
@@ -570,7 +595,7 @@ namespace {
   // been consumed, the user stops the search, or the maximum search depth is
   // reached.
 
-  void id_loop(const Position &pos, Move searchMoves[]) {
+  Value id_loop(const Position &pos, Move searchMoves[]) {
     Position p(pos);
     SearchStack ss[PLY_MAX_PLUS_2];
 
@@ -694,6 +719,7 @@ namespace {
       LogFile << "Ponder move: " << move_to_san(p, ss[0].pv[1]) << '\n';
       LogFile << std::endl;
     }
+    return rml.get_move_score(0);
   }
 
 
@@ -905,6 +931,7 @@ namespace {
     {
       assert(move_is_ok(move));
 
+      bool lastMinuteSurprise = (depth <= OnePly && mp.current_move_type() == MovePicker::PH_GOOD_CAPTURES);
       bool singleReply = (pos.is_check() && mp.number_of_moves() == 1);
       bool moveIsCheck = pos.move_is_check(move, dcCandidates);
       bool moveIsCapture = pos.move_is_capture(move);
@@ -916,7 +943,7 @@ namespace {
         PawnValueMidgame : pos.midgame_value_of_piece_on(move_to(move));
 
       // Decide the new search depth
-      Depth ext = extension(pos, move, true, moveIsCheck, singleReply, mateThreat);
+      Depth ext = extension(pos, move, true, moveIsCheck, singleReply || lastMinuteSurprise, mateThreat);
       Depth newDepth = depth - OnePly + ext;
 
       // Make and search the move
@@ -1970,26 +1997,35 @@ namespace {
 
   Depth extension(const Position &pos, Move m, bool pvNode,
                   bool check, bool singleReply, bool mateThreat) {
+
     Depth result = Depth(0);
 
-    if(check)
-      result += CheckExtension[pvNode];
-    if(singleReply)
-      result += SingleReplyExtension[pvNode];
-    if(pos.move_is_pawn_push_to_7th(m))
-      result += PawnPushTo7thExtension[pvNode];
-    if(pos.move_is_passed_pawn_push(m))
-      result += PassedPawnExtension[pvNode];
-    if(mateThreat)
-      result += MateThreatExtension[pvNode];
-    if(pos.midgame_value_of_piece_on(move_to(m)) >= RookValueMidgame
-       && (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
-           - pos.midgame_value_of_piece_on(move_to(m)) == Value(0))
-       && !move_promotion(m))
-      result += PawnEndgameExtension[pvNode];
-    if(pvNode && pos.move_is_capture(m)
-       && pos.type_of_piece_on(move_to(m)) != PAWN && pos.see(m) >= 0)
-      result += OnePly/2;
+    if (check)
+        result += CheckExtension[pvNode];
+
+    if (singleReply)
+        result += SingleReplyExtension[pvNode];
+
+    if (pos.move_is_pawn_push_to_7th(m))
+        result += PawnPushTo7thExtension[pvNode];
+
+    if (pos.move_is_passed_pawn_push(m))
+        result += PassedPawnExtension[pvNode];
+
+    if (mateThreat)
+        result += MateThreatExtension[pvNode];
+
+    if (   pos.midgame_value_of_piece_on(move_to(m)) >= RookValueMidgame
+        && (  pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK)
+            - pos.midgame_value_of_piece_on(move_to(m)) == Value(0))
+        && !move_promotion(m))
+        result += PawnEndgameExtension[pvNode];
+    
+    if (   pvNode
+        && pos.move_is_capture(m)
+        && pos.type_of_piece_on(move_to(m)) != PAWN
+        && pos.see(m) >= 0)
+        result += OnePly/2;
 
     return Min(result, OnePly);
   }