Better check evasion move sorting

Use in addition the counter move history table for sorting quiet
check evasion moves in main and quiecence search. Also rename
"contHistory" to "continuationHistory" while there.

STC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 73284 W: 16433 L: 15938 D: 40913
http://tests.stockfishchess.org/tests/view/5b4f526e0ebc5902bdb7a401

LTC:
LLR: 2.96 (-2.94,2.94) [0.00,5.00]
Total: 12135 W: 2171 L: 1997 D: 7967
http://tests.stockfishchess.org/tests/view/5b4fc0ef0ebc5902bdb7ae0e

Closes https://github.com/official-stockfish/Stockfish/pull/1685

Bench 4817583

diff --git a/src/movepick.cpp b/src/movepick.cpp
index e1042ea6005f0255ccb1f4b21f809e0f0e4a3b84..8f49b1dd434cf66ae1ccce0475d02dd3c45814df 100644 (file)
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -61,7 +61,7 @@ namespace {
 /// MovePicker constructor for the main search
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
                        const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers)
 /// MovePicker constructor for the main search
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
                        const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers)

-           : pos(p), mainHistory(mh), captureHistory(cph), contHistory(ch),
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch),

              refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
 
   assert(d > DEPTH_ZERO);
              refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) {
 
   assert(d > DEPTH_ZERO);


@@ -73,8 +73,8 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHist
 
 /// MovePicker constructor for quiescence search
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,
 
 /// MovePicker constructor for quiescence search
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh,

-                       const CapturePieceToHistory* cph, Square rs)
-           : pos(p), mainHistory(mh), captureHistory(cph), recaptureSquare(rs), depth(d) {
+                       const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs)
+           : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), recaptureSquare(rs), depth(d) {

 
   assert(d <= DEPTH_ZERO);
 
 
   assert(d <= DEPTH_ZERO);
 


@@ -115,9 +115,9 @@ void MovePicker::score() {
 
       else if (Type == QUIETS)
           m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
 
       else if (Type == QUIETS)
           m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]

-                   + (*contHistory[0])[pos.moved_piece(m)][to_sq(m)]
-                   + (*contHistory[1])[pos.moved_piece(m)][to_sq(m)]
-                   + (*contHistory[3])[pos.moved_piece(m)][to_sq(m)];
+                   + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+                   + (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)]
+                   + (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)];

 
       else // Type == EVASIONS
       {
 
       else // Type == EVASIONS
       {


@@ -125,7 +125,9 @@ void MovePicker::score() {
               m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
                        - Value(type_of(pos.moved_piece(m)));
           else
               m.value =  PieceValue[MG][pos.piece_on(to_sq(m))]
                        - Value(type_of(pos.moved_piece(m)));
           else

-              m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - (1 << 28);
+              m.value =  (*mainHistory)[pos.side_to_move()][from_to(m)]
+                       + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]
+                       - (1 << 28);

       }
 }
 
       }
 }
 

diff --git a/src/movepick.h b/src/movepick.h
index b6e5620e5e333bd9a782ff70fe967a81dfc3c8c0..503bfae1d8cc9fd97145abb5d3f014d24235f7a5 100644 (file)
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -119,6 +119,7 @@ public:
   MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
   MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
                                            const CapturePieceToHistory*,
   MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
   MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
                                            const CapturePieceToHistory*,

+                                           const PieceToHistory**,

                                            Square);
   MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
                                            const CapturePieceToHistory*,
                                            Square);
   MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
                                            const CapturePieceToHistory*,


@@ -136,7 +137,7 @@ private:
   const Position& pos;
   const ButterflyHistory* mainHistory;
   const CapturePieceToHistory* captureHistory;
   const Position& pos;
   const ButterflyHistory* mainHistory;
   const CapturePieceToHistory* captureHistory;

-  const PieceToHistory** contHistory;
+  const PieceToHistory** continuationHistory;

   Move ttMove;
   ExtMove refutations[3], *cur, *endMoves, *endBadCaptures;
   int stage;
   Move ttMove;
   ExtMove refutations[3], *cur, *endMoves, *endBadCaptures;
   int stage;

diff --git a/src/search.cpp b/src/search.cpp
index 9a826d3724dc43bc7e6e8bff935f064ac18d5104..0619db3a12a2420a2ef85864ab84e709c614a158 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -290,7 +290,7 @@ void Thread::search() {
 
   std::memset(ss-4, 0, 7 * sizeof(Stack));
   for (int i = 4; i > 0; i--)
 
   std::memset(ss-4, 0, 7 * sizeof(Stack));
   for (int i = 4; i > 0; i--)

-     (ss-i)->contHistory = this->contHistory[NO_PIECE][0].get(); // Use as sentinel
+     (ss-i)->continuationHistory = this->continuationHistory[NO_PIECE][0].get(); // Use as sentinel

 
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
 
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;


@@ -587,7 +587,7 @@ namespace {
 
     (ss+1)->ply = ss->ply + 1;
     ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
 
     (ss+1)->ply = ss->ply + 1;
     ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;

-    ss->contHistory = thisThread->contHistory[NO_PIECE][0].get();
+    ss->continuationHistory = thisThread->continuationHistory[NO_PIECE][0].get();

     (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
     Square prevSq = to_sq((ss-1)->currentMove);
 
     (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
     Square prevSq = to_sq((ss-1)->currentMove);
 


@@ -751,7 +751,7 @@ namespace {
         Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         ss->currentMove = MOVE_NULL;
         Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         ss->currentMove = MOVE_NULL;

-        ss->contHistory = thisThread->contHistory[NO_PIECE][0].get();
+        ss->continuationHistory = thisThread->continuationHistory[NO_PIECE][0].get();

 
         pos.do_null_move(st);
 
 
         pos.do_null_move(st);
 


@@ -802,7 +802,7 @@ namespace {
                 probCutCount++;
 
                 ss->currentMove = move;
                 probCutCount++;
 
                 ss->currentMove = move;

-                ss->contHistory = thisThread->contHistory[pos.moved_piece(move)][to_sq(move)].get();
+                ss->continuationHistory = thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)].get();

 
                 assert(depth >= 5 * ONE_PLY);
 
 
                 assert(depth >= 5 * ONE_PLY);
 


@@ -835,7 +835,7 @@ namespace {
 
 moves_loop: // When in check, search starts from here
 
 
 moves_loop: // When in check, search starts from here
 

-    const PieceToHistory* contHist[] = { (ss-1)->contHistory, (ss-2)->contHistory, nullptr, (ss-4)->contHistory };
+    const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory, nullptr, (ss-4)->continuationHistory };

     Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
 
     MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory,
     Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq];
 
     MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory,


@@ -970,7 +970,7 @@ moves_loop: // When in check, search starts from here
 
       // Update the current move (this must be done after singular extension search)
       ss->currentMove = move;
 
       // Update the current move (this must be done after singular extension search)
       ss->currentMove = move;

-      ss->contHistory = thisThread->contHistory[movedPiece][to_sq(move)].get();
+      ss->continuationHistory = thisThread->continuationHistory[movedPiece][to_sq(move)].get();

 
       // Step 15. Make the move
       pos.do_move(move, st, givesCheck);
 
       // Step 15. Make the move
       pos.do_move(move, st, givesCheck);


@@ -1212,8 +1212,10 @@ moves_loop: // When in check, search starts from here
         ss->pv[0] = MOVE_NONE;
     }
 
         ss->pv[0] = MOVE_NONE;
     }
 

+    Thread* thisThread = pos.this_thread();

     (ss+1)->ply = ss->ply + 1;
     ss->currentMove = bestMove = MOVE_NONE;
     (ss+1)->ply = ss->ply + 1;
     ss->currentMove = bestMove = MOVE_NONE;

+    ss->continuationHistory = thisThread->continuationHistory[NO_PIECE][0].get();

     inCheck = pos.checkers();
     moveCount = 0;
 
     inCheck = pos.checkers();
     moveCount = 0;
 


@@ -1283,12 +1285,15 @@ moves_loop: // When in check, search starts from here
         futilityBase = bestValue + 128;
     }
 
         futilityBase = bestValue + 128;
     }
 

+    const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory, nullptr, (ss-4)->continuationHistory };
+

     // Initialize a MovePicker object for the current position, and prepare
     // to search the moves. Because the depth is <= 0 here, only captures,
     // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
     // be generated.
     // Initialize a MovePicker object for the current position, and prepare
     // to search the moves. Because the depth is <= 0 here, only captures,
     // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will
     // be generated.

-    MovePicker mp(pos, ttMove, depth, &pos.this_thread()->mainHistory,
-                                      &pos.this_thread()->captureHistory,
+    MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory,
+                                      &thisThread->captureHistory,
+                                      contHist,

                                       to_sq((ss-1)->currentMove));
 
     // Loop through the moves until no moves remain or a beta cutoff occurs
                                       to_sq((ss-1)->currentMove));
 
     // Loop through the moves until no moves remain or a beta cutoff occurs


@@ -1345,6 +1350,7 @@ moves_loop: // When in check, search starts from here
       }
 
       ss->currentMove = move;
       }
 
       ss->currentMove = move;

+      ss->continuationHistory = thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)].get();

 
       // Make and search the move
       pos.do_move(move, st, givesCheck);
 
       // Make and search the move
       pos.do_move(move, st, givesCheck);


@@ -1436,7 +1442,7 @@ moves_loop: // When in check, search starts from here
 
     for (int i : {1, 2, 4})
         if (is_ok((ss-i)->currentMove))
 
     for (int i : {1, 2, 4})
         if (is_ok((ss-i)->currentMove))

-            (*(ss-i)->contHistory)[pc][to] << bonus;
+            (*(ss-i)->continuationHistory)[pc][to] << bonus;

   }
 
 
   }
 
 

diff --git a/src/search.h b/src/search.h
index 26ec6f01c37903ecc1e7e6fe9d0a503a3805d412..e3ac5ab6a78edcb111be4df4103989aa98e5f263 100644 (file)
--- a/src/search.h
+++ b/src/search.h
@@ -41,7 +41,7 @@ constexpr int CounterMovePruneThreshold = 0;
 
 struct Stack {
   Move* pv;
 
 struct Stack {
   Move* pv;

-  PieceToHistory* contHistory;
+  PieceToHistory* continuationHistory;

   int ply;
   Move currentMove;
   Move excludedMove;
   int ply;
   Move currentMove;
   Move excludedMove;

diff --git a/src/thread.cpp b/src/thread.cpp
index f9809275ec2485a49ee737f5d00a4a78065ffb17..8b13f6e34907e1f0b98d75f13311f5b3a15f96ce 100644 (file)
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -61,11 +61,11 @@ void Thread::clear() {
   mainHistory.fill(0);
   captureHistory.fill(0);
 
   mainHistory.fill(0);
   captureHistory.fill(0);
 

-  for (auto& to : contHistory)
+  for (auto& to : continuationHistory)

       for (auto& h : to)
           h.get()->fill(0);
 
       for (auto& h : to)
           h.get()->fill(0);
 

-  contHistory[NO_PIECE][0].get()->fill(Search::CounterMovePruneThreshold - 1);
+  continuationHistory[NO_PIECE][0].get()->fill(Search::CounterMovePruneThreshold - 1);

 }
 
 /// Thread::start_searching() wakes up the thread that will start the search
 }
 
 /// Thread::start_searching() wakes up the thread that will start the search

diff --git a/src/thread.h b/src/thread.h
index f3dba3518de32c4fb4d5fa39350d0d2fffe6face..74d6e7617983e5e244690eec8157d4b09996d17d 100644 (file)
--- a/src/thread.h
+++ b/src/thread.h
@@ -71,7 +71,7 @@ public:
   CounterMoveHistory counterMoves;
   ButterflyHistory mainHistory;
   CapturePieceToHistory captureHistory;
   CounterMoveHistory counterMoves;
   ButterflyHistory mainHistory;
   CapturePieceToHistory captureHistory;

-  ContinuationHistory contHistory;
+  ContinuationHistory continuationHistory;

   Score contempt;
 };
 
   Score contempt;
 };