X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmovepick.cpp;h=1a8f5bf60ea4a9cc50c6ed7e5b666f04d4992277;hb=ace27831eede5095f6ae70da14183bd0ec8e78b4;hp=61e5527f42c61d638132201f0b2f2efd18bc999a;hpb=8647fbd6ed11c60282e84e4b486a7e8258c88483;p=stockfish

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 61e5527f..1a8f5bf6 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -37,6 +37,7 @@ namespace {
     PH_BAD_CAPTURES,  // Queen promotions and captures with SEE values < captureThreshold (captureThreshold <= 0)
     PH_EVASIONS,      // Check evasions
     PH_QCAPTURES,     // Captures in quiescence search
+    PH_QRECAPTURES,   // Recaptures in quiescence search
     PH_QCHECKS,       // Non-capture checks in quiescence search
     PH_STOP
   };
@@ -46,6 +47,7 @@ namespace {
   const uint8_t EvasionTable[] = { PH_TT_MOVE, PH_EVASIONS, PH_STOP };
   const uint8_t QsearchWithChecksTable[] = { PH_TT_MOVE, PH_QCAPTURES, PH_QCHECKS, PH_STOP };
   const uint8_t QsearchWithoutChecksTable[] = { PH_TT_MOVE, PH_QCAPTURES, PH_STOP };
+  const uint8_t QsearchRecapturesTable[] = { PH_TT_MOVE, PH_QRECAPTURES, PH_STOP };
   const uint8_t ProbCutTable[] = { PH_TT_MOVE, PH_GOOD_PROBCUT, PH_STOP };
 }
 
@@ -85,7 +87,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
   go_next_phase();
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h)
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, Square recaptureSq)
                       : pos(p), H(h) {
 
   assert(d <= DEPTH_ZERO);
@@ -94,16 +96,22 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h)
       phasePtr = EvasionTable;
   else if (d >= DEPTH_QS_CHECKS)
       phasePtr = QsearchWithChecksTable;
-  else
+  else if (d >= DEPTH_QS_RECAPTURES)
   {
       phasePtr = QsearchWithoutChecksTable;
 
       // Skip TT move if is not a capture or a promotion, this avoids
       // qsearch tree explosion due to a possible perpetual check or
       // similar rare cases when TT table is full.
-      if (ttm != MOVE_NONE && !pos.move_is_capture(ttm) && !move_is_promotion(ttm))
+      if (ttm != MOVE_NONE && !pos.move_is_capture_or_promotion(ttm))
           ttm = MOVE_NONE;
   }
+  else
+  {
+      phasePtr = QsearchRecapturesTable;
+      recaptureSquare = recaptureSq;
+      ttm = MOVE_NONE;
+  }
 
   ttMove = (ttm && pos.move_is_pl(ttm) ? ttm : MOVE_NONE);
   phasePtr += int(ttMove == MOVE_NONE) - 1;
@@ -184,6 +192,10 @@ void MovePicker::go_next_phase() {
       score_captures();
       return;
 
+  case PH_QRECAPTURES:
+      lastMove = generate<MV_CAPTURE>(pos, moves);
+      return;
+
   case PH_QCHECKS:
       lastMove = generate<MV_NON_CAPTURE_CHECK>(pos, moves);
       return;
@@ -224,11 +236,11 @@ void MovePicker::score_captures() {
   for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
       m = cur->move;
+      cur->score =  pos.midgame_value_of_piece_on(move_to(m))
+                  - pos.type_of_piece_on(move_from(m));
+
       if (move_is_promotion(m))
-          cur->score = QueenValueMidgame;
-      else
-          cur->score =  pos.midgame_value_of_piece_on(move_to(m))
-                      - pos.type_of_piece_on(move_from(m));
+          cur->score += QueenValueMidgame;
   }
 }
 
@@ -347,6 +359,12 @@ Move MovePicker::get_next_move() {
               return move;
           break;
 
+      case PH_QRECAPTURES:
+          move = (curMove++)->move;
+          if (move_to(move) == recaptureSquare)
+              return move;
+          break;
+
       case PH_QCHECKS:
           move = (curMove++)->move;
           if (move != ttMove)