X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=c52384947a6381008b661b5d70d5c8496ea34f9b;hp=9dd91f278df644f8727ae4e7d66c634248177133;hb=24dac5ccd309837c6767dcf6b145be385eea2e21;hpb=55758344d3ccf49353bcd8f3a06a4553ff1b753a

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 9dd91f27..c5238494 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -2,13 +2,13 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, 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
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
 
-
   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
@@ -51,7 +51,7 @@ namespace {
 
   // pick_best() finds the best move in the range (begin, end) and moves it to
   // the front. It's faster than sorting all the moves in advance when there
-  // are few moves e.g. the possible captures.
+  // are few moves, e.g., the possible captures.
   Move pick_best(ExtMove* begin, ExtMove* end)
   {
       std::swap(*begin, *std::max_element(begin, end));
@@ -64,12 +64,14 @@ namespace {
 /// Constructors of the MovePicker class. As arguments we pass information
 /// to help it to return the (presumably) good moves first, to decide which
 /// moves to return (in the quiescence search, for instance, we only want to
-/// search captures, promotions and some checks) and how important good move
+/// search captures, promotions, and some checks) and how important good move
 /// ordering is at the current node.
 
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
-                       const CounterMovesHistoryStats& cmh, Move cm, Search::Stack* s)
-           : pos(p), history(h), counterMovesHistory(cmh), ss(s), countermove(cm), depth(d) {
+                       const CounterMoveStats& cmh, const CounterMoveStats& fmh,
+                       Move cm, Search::Stack* s)
+           : pos(p), history(h), counterMoveHistory(&cmh),
+             followupMoveHistory(&fmh), ss(s), countermove(cm), depth(d) {
 
   assert(d > DEPTH_ZERO);
 
@@ -78,9 +80,9 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats&
   endMoves += (ttMove != MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h,
-                       const CounterMovesHistoryStats& cmh, Square s)
-           : pos(p), history(h), counterMovesHistory(cmh) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d,
+                       const HistoryStats& h, Square s)
+           : pos(p), history(h) {
 
   assert(d <= DEPTH_ZERO);
 
@@ -104,9 +106,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats&
   endMoves += (ttMove != MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h,
-                       const CounterMovesHistoryStats& cmh, Value th)
-           : pos(p), history(h), counterMovesHistory(cmh), threshold(th) {
+MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, Value th)
+           : pos(p), history(h), threshold(th) {
 
   assert(!pos.checkers());
 
@@ -128,9 +129,9 @@ template<>
 void MovePicker::score<CAPTURES>() {
   // Winning and equal captures in the main search are ordered by MVV, preferring
   // captures near our home rank. Surprisingly, this appears to perform slightly
-  // better than SEE based move ordering: exchanging big pieces before capturing
+  // better than SEE-based move ordering: exchanging big pieces before capturing
   // a hanging piece probably helps to reduce the subtree size.
-  // In main search we want to push captures with negative SEE values to the
+  // In the main search we want to push captures with negative SEE values to the
   // badCaptures[] array, but instead of doing it now we delay until the move
   // has been picked up, saving some SEE calls in case we get a cutoff.
   for (auto& m : *this)
@@ -141,19 +142,17 @@ void MovePicker::score<CAPTURES>() {
 template<>
 void MovePicker::score<QUIETS>() {
 
-  Square prevSq = to_sq((ss-1)->currentMove);
-  const HistoryStats& cmh = counterMovesHistory[pos.piece_on(prevSq)][prevSq];
-
   for (auto& m : *this)
       m.value =  history[pos.moved_piece(m)][to_sq(m)]
-               + cmh[pos.moved_piece(m)][to_sq(m)];
+               + (*counterMoveHistory )[pos.moved_piece(m)][to_sq(m)]
+               + (*followupMoveHistory)[pos.moved_piece(m)][to_sq(m)];
 }
 
 template<>
 void MovePicker::score<EVASIONS>() {
-  // Try winning and equal captures captures ordered by MVV/LVA, then non-captures
-  // ordered by history value, then bad-captures and quiet moves with a negative
-  // SEE ordered by SEE value.
+  // Try winning and equal captures ordered by MVV/LVA, then non-captures ordered
+  // by history value, then bad captures and quiet moves with a negative SEE ordered
+  // by SEE value.
   Value see;
 
   for (auto& m : *this)
@@ -168,7 +167,7 @@ void MovePicker::score<EVASIONS>() {
 }
 
 
-/// generate_next_stage() generates, scores and sorts the next bunch of moves,
+/// generate_next_stage() generates, scores, and sorts the next bunch of moves
 /// when there are no more moves to try for the current stage.
 
 void MovePicker::generate_next_stage() {