Don't compensate TT for evaluation drift

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 61475a2f3f3be641fc19b2222d5665cc85d1f214..ac4d85b69996eb7abadda3cf61fcd9d50ec39cf7 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -190,9 +190,6 @@ namespace {
   // Remaining depth:                 1 ply         1.5 ply       2 ply         2.5 ply       3 ply         3.5 ply
   const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) };
 
-  // The main transposition table
-  TranspositionTable TT;
-
 
   /// Variables initialized by UCI options
 
@@ -919,7 +916,7 @@ namespace {
         else
         {
             if (   newDepth >= 3*OnePly
-                && i >= MultiPV + LMRPVMoves - 2 // Remove -2 and decrease LMRPVMoves instead ?
+                && i >= MultiPV + LMRPVMoves
                 && !dangerous
                 && !moveIsCapture
                 && !move_is_promotion(move)
@@ -1094,16 +1091,16 @@ namespace {
 
     // Initialize a MovePicker object for the current position, and prepare
     // to search all moves
-    MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
-
     Move move, movesSearched[256];
     int moveCount = 0;
     Value value, bestValue = -VALUE_INFINITE;
-    Bitboard dcCandidates = mp.discovered_check_candidates();
     Color us = pos.side_to_move();
     bool isCheck = pos.is_check();
     bool mateThreat = pos.has_mate_threat(opposite_color(us));
 
+    MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]);
+    Bitboard dcCandidates = mp.discovered_check_candidates();
+
     // Loop through all legal moves until no moves remain or a beta cutoff
     // occurs.
     while (   alpha < beta
@@ -1112,7 +1109,7 @@ namespace {
     {
       assert(move_is_ok(move));
 
-      bool singleReply = (isCheck && mp.number_of_moves() == 1);
+      bool singleReply = (isCheck && mp.number_of_evasions() == 1);
       bool moveIsCheck = pos.move_is_check(move, dcCandidates);
       bool moveIsCapture = pos.move_is_capture(move);
 
@@ -1126,7 +1123,6 @@ namespace {
       // Make and search the move
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
-      TT.prefetch(pos.get_key());
 
       if (moveCount == 1) // The first move in list is the PV
           value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID);
@@ -1297,8 +1293,6 @@ namespace {
 
         StateInfo st;
         pos.do_null_move(st);
-        TT.prefetch(pos.get_key());
-
         int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction
 
         Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID);
@@ -1372,7 +1366,7 @@ namespace {
     {
       assert(move_is_ok(move));
 
-      bool singleReply = (isCheck && mp.number_of_moves() == 1);
+      bool singleReply = (isCheck && mp.number_of_evasions() == 1);
       bool moveIsCheck = pos.move_is_check(move, dcCandidates);
       bool moveIsCapture = pos.move_is_capture(move);
 
@@ -1413,7 +1407,6 @@ namespace {
       // Make and search the move
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
-      TT.prefetch(pos.get_key());
 
       // Try to reduce non-pv search depth by one ply if move seems not problematic,
       // if the move fails high will be re-searched at full depth.
@@ -1547,10 +1540,10 @@ namespace {
         // Use the cached evaluation score if possible
         assert(ei.futilityMargin == Value(0));
 
-        staticValue = tte->value();
+        staticValue = tte->value() + ply;
     }
     else
-        staticValue = evaluate(pos, ei, threadID);
+        staticValue = evaluate(pos, ei, threadID) + ply;
 
     if (ply == PLY_MAX - 1)
         return evaluate(pos, ei, threadID);
@@ -1623,7 +1616,6 @@ namespace {
       // Make and search the move.
       StateInfo st;
       pos.do_move(move, st, dcCandidates);
-      TT.prefetch(pos.get_key());
       Value value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID);
       pos.undo_move(move);
 
@@ -1970,15 +1962,15 @@ namespace {
     bool includeAllMoves = (searchMoves[0] == MOVE_NONE);
 
     // Generate all legal moves
-    int lm_count = generate_legal_moves(pos, mlist);
+    MoveStack* last = generate_legal_moves(pos, mlist);
 
     // Add each move to the moves[] array
-    for (int i = 0; i < lm_count; i++)
+    for (MoveStack* cur = mlist; cur != last; cur++)
     {
         bool includeMove = includeAllMoves;
 
         for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++)
-            includeMove = (searchMoves[k] == mlist[i].move);
+            includeMove = (searchMoves[k] == cur->move);
 
         if (!includeMove)
             continue;
@@ -1987,7 +1979,7 @@ namespace {
         StateInfo st;
         SearchStack ss[PLY_MAX_PLUS_2];
 
-        moves[count].move = mlist[i].move;
+        moves[count].move = cur->move;
         pos.do_move(moves[count].move, st);
         moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0);
         pos.undo_move(moves[count].move);
@@ -2193,7 +2185,7 @@ namespace {
     // Case 5: Discovered check, checking piece is the piece moved in m1
     if (   piece_is_slider(pos.piece_on(t1))
         && bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), f2)
-        && !bit_is_set(squares_between(t2, pos.king_square(pos.side_to_move())), t2))
+        && !bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), t2))
     {
         Bitboard occ = pos.occupied_squares();
         Color us = pos.side_to_move();
@@ -2275,12 +2267,13 @@ namespace {
 
     if (pos.type_of_piece_on(move_from(m)) == PAWN)
     {
-        if (pos.move_is_pawn_push_to_7th(m))
+        Color c = pos.side_to_move();
+        if (relative_rank(c, move_to(m)) == RANK_7)
         {
             result += PawnPushTo7thExtension[pvNode];
             *dangerous = true;
         }
-        if (pos.move_is_passed_pawn_push(m))
+        if (pos.pawn_is_passed(c, move_to(m)))
         {
             result += PassedPawnExtension[pvNode];
             *dangerous = true;