X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=b09647953a7fe50a6647d0c21668dcea340d20d6;hp=88b4fe9c6ab9bf320832e34642b7f657de95f186;hb=b84af67f4c88f3e3f7b61bf2035475f79fb3e62e;hpb=3141490374182551ed26f39ba4e3efb59589f057

diff --git a/src/movepick.cpp b/src/movepick.cpp
index 88b4fe9c..b0964795 100644
--- a/src/movepick.cpp
+++ b/src/movepick.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2012 Marco Costalba, Joona Kiiski, 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
@@ -23,39 +23,25 @@
 
 #include "movegen.h"
 #include "movepick.h"
-#include "search.h"
-#include "types.h"
+#include "thread.h"
 
 namespace {
 
-  enum MovegenPhase {
-    PH_TT_MOVE,       // Transposition table move
-    PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= captureThreshold (captureThreshold <= 0)
-    PH_GOOD_PROBCUT,  // Queen promotions and captures with SEE values > captureThreshold (captureThreshold >= 0)
-    PH_KILLERS,       // Killer moves from the current ply
-    PH_NONCAPTURES_1, // Non-captures and underpromotions with positive score
-    PH_NONCAPTURES_2, // Non-captures and underpromotions with non-positive score
-    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
+  enum Sequencer {
+    MAIN_SEARCH, CAPTURES_S1, KILLERS_S1, QUIETS_1_S1, QUIETS_2_S1, BAD_CAPTURES_S1,
+    EVASION,     EVASIONS_S2,
+    QSEARCH_0,   CAPTURES_S3, QUIET_CHECKS_S3,
+    QSEARCH_1,   CAPTURES_S4,
+    PROBCUT,     CAPTURES_S5,
+    RECAPTURE,   CAPTURES_S6,
+    STOP
   };
 
-  CACHE_LINE_ALIGNMENT
-  const uint8_t MainSearchTable[] = { PH_TT_MOVE, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES_1, PH_NONCAPTURES_2, PH_BAD_CAPTURES, PH_STOP };
-  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 };
-
   // Unary predicate used by std::partition to split positive scores from remaining
   // ones so to sort separately the two sets, and with the second sort delayed.
   inline bool has_positive_score(const MoveStack& move) { return move.score > 0; }
 
-  // Picks and pushes to the front the best move in range [firstMove, lastMove),
+  // Picks and moves to the front the best move in the range [firstMove, lastMove),
   // it is faster than sorting all the moves in advance when moves are few, as
   // normally are the possible captures.
   inline MoveStack* pick_best(MoveStack* firstMove, MoveStack* lastMove)
@@ -65,171 +51,100 @@ namespace {
   }
 }
 
-/// Constructors for the MovePicker class. As arguments we pass information
+
+/// 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 about how important good
 /// move ordering is at the current node.
 
 MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
-                       SearchStack* ss, Value beta) : pos(p), H(h), depth(d) {
-  captureThreshold = 0;
-  badCaptures = moves + MAX_MOVES;
+                       Search::Stack* s, Value beta) : pos(p), H(h), depth(d) {
 
   assert(d > DEPTH_ZERO);
 
+  captureThreshold = 0;
+  curMove = lastMove = moves;
+  lastBadCapture = moves + MAX_MOVES - 1;
+  ss = s;
+
   if (p.in_check())
-  {
-      killers[0].move = killers[1].move = MOVE_NONE;
-      phasePtr = EvasionTable;
-  }
+      phase = EVASION;
+
   else
   {
+      phase = MAIN_SEARCH;
+
       killers[0].move = ss->killers[0];
       killers[1].move = ss->killers[1];
 
-      // Consider sligtly negative captures as good if at low
-      // depth and far from beta.
-      if (ss && ss->eval < beta - PawnValueMidgame && d < 3 * ONE_PLY)
-          captureThreshold = -PawnValueMidgame;
+      // Consider sligtly negative captures as good if at low depth and far from beta
+      if (ss && ss->eval < beta - PawnValueMg && d < 3 * ONE_PLY)
+          captureThreshold = -PawnValueMg;
 
-      phasePtr = MainSearchTable;
+      // Consider negative captures as good if still enough to reach beta
+      else if (ss && ss->eval > beta)
+          captureThreshold = beta - ss->eval;
   }
 
   ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
-  phasePtr += int(ttMove == MOVE_NONE) - 1;
-  go_next_phase();
+  lastMove += (ttMove != MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, Square recaptureSq)
-                      : pos(p), H(h) {
+MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h,
+                       Square sq) : pos(p), H(h), curMove(moves), lastMove(moves) {
 
   assert(d <= DEPTH_ZERO);
 
   if (p.in_check())
-      phasePtr = EvasionTable;
-  else if (d >= DEPTH_QS_CHECKS)
-      phasePtr = QsearchWithChecksTable;
-  else if (d >= DEPTH_QS_RECAPTURES)
+      phase = EVASION;
+
+  else if (d > DEPTH_QS_NO_CHECKS)
+      phase = QSEARCH_0;
+
+  else if (d > DEPTH_QS_RECAPTURES)
   {
-      phasePtr = QsearchWithoutChecksTable;
+      phase = QSEARCH_1;
 
-      // 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.is_capture_or_promotion(ttm))
+      // 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 && !pos.is_capture_or_promotion(ttm))
           ttm = MOVE_NONE;
   }
   else
   {
-      phasePtr = QsearchRecapturesTable;
-      recaptureSquare = recaptureSq;
+      phase = RECAPTURE;
+      recaptureSquare = sq;
       ttm = MOVE_NONE;
   }
 
   ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
-  phasePtr += int(ttMove == MOVE_NONE) - 1;
-  go_next_phase();
+  lastMove += (ttMove != MOVE_NONE);
 }
 
-MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType parentCapture)
-                       : pos(p), H(h) {
-
-  assert (!pos.in_check());
+MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt)
+                       : pos(p), H(h), curMove(moves), lastMove(moves) {
 
-  // In ProbCut we consider only captures better than parent's move
-  captureThreshold = piece_value_midgame(Piece(parentCapture));
-  phasePtr = ProbCutTable;
+  assert(!pos.in_check());
 
-  if (   ttm != MOVE_NONE
-      && (!pos.is_capture(ttm) ||  pos.see(ttm) <= captureThreshold))
-      ttm = MOVE_NONE;
+  phase = PROBCUT;
 
+  // In ProbCut we generate only captures better than parent's captured piece
+  captureThreshold = PieceValue[Mg][pt];
   ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE);
-  phasePtr += int(ttMove == MOVE_NONE) - 1;
-  go_next_phase();
-}
-
-
-/// MovePicker::go_next_phase() generates, scores and sorts the next bunch
-/// of moves when there are no more moves to try for the current phase.
-
-void MovePicker::go_next_phase() {
-
-  curMove = moves;
-  phase = *(++phasePtr);
-  switch (phase) {
-
-  case PH_TT_MOVE:
-      lastMove = curMove + 1;
-      return;
-
-  case PH_GOOD_CAPTURES:
-  case PH_GOOD_PROBCUT:
-      lastMove = generate<MV_CAPTURE>(pos, moves);
-      score_captures();
-      return;
-
-  case PH_KILLERS:
-      curMove = killers;
-      lastMove = curMove + 2;
-      return;
-
-  case PH_NONCAPTURES_1:
-      lastNonCapture = lastMove = generate<MV_NON_CAPTURE>(pos, moves);
-      score_noncaptures();
-      lastMove = std::partition(curMove, lastMove, has_positive_score);
-      sort<MoveStack>(curMove, lastMove);
-      return;
 
-  case PH_NONCAPTURES_2:
-      curMove = lastMove;
-      lastMove = lastNonCapture;
-      if (depth >= 3 * ONE_PLY)
-          sort<MoveStack>(curMove, lastMove);
-      return;
+  if (ttMove && (!pos.is_capture(ttMove) ||  pos.see(ttMove) <= captureThreshold))
+      ttMove = MOVE_NONE;
 
-  case PH_BAD_CAPTURES:
-      // Bad captures SEE value is already calculated so just pick
-      // them in order to get SEE move ordering.
-      curMove = badCaptures;
-      lastMove = moves + MAX_MOVES;
-      return;
-
-  case PH_EVASIONS:
-      assert(pos.in_check());
-      lastMove = generate<MV_EVASION>(pos, moves);
-      score_evasions();
-      return;
-
-  case PH_QCAPTURES:
-      lastMove = generate<MV_CAPTURE>(pos, moves);
-      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;
-
-  case PH_STOP:
-      lastMove = curMove + 1; // Avoid another go_next_phase() call
-      return;
-
-  default:
-      assert(false);
-      return;
-  }
+  lastMove += (ttMove != MOVE_NONE);
 }
 
 
 /// MovePicker::score_captures(), MovePicker::score_noncaptures() and
 /// MovePicker::score_evasions() assign a numerical move ordering score
 /// to each move in a move list.  The moves with highest scores will be
-/// picked first by get_next_move().
+/// picked first by next_move().
 
 void MovePicker::score_captures() {
   // Winning and equal captures in the main search are ordered by MVV/LVA.
@@ -247,40 +162,35 @@ void MovePicker::score_captures() {
   // some SEE calls in case we get a cutoff (idea from Pablo Vazquez).
   Move m;
 
-  // Use MVV/LVA ordering
   for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
       m = cur->move;
-      cur->score =  piece_value_midgame(pos.piece_on(move_to(m)))
-                  - type_of(pos.piece_on(move_from(m)));
+      cur->score =  PieceValue[Mg][pos.piece_on(to_sq(m))]
+                  - type_of(pos.piece_moved(m));
 
-      if (is_promotion(m))
-          cur->score += piece_value_midgame(Piece(promotion_piece_type(m)));
+      if (type_of(m) == PROMOTION)
+          cur->score += PieceValue[Mg][promotion_type(m)];
   }
 }
 
 void MovePicker::score_noncaptures() {
 
   Move m;
-  Square from;
 
   for (MoveStack* cur = moves; cur != lastMove; cur++)
   {
       m = cur->move;
-      from = move_from(m);
-      cur->score = H.value(pos.piece_on(from), move_to(m));
+      cur->score = H.value(pos.piece_moved(m), to_sq(m));
   }
 }
 
 void MovePicker::score_evasions() {
-  // Try good captures ordered by MVV/LVA, then non-captures if
-  // destination square is not under attack, ordered by history
-  // value, and at the end bad-captures and non-captures with a
-  // negative SEE. This last group is ordered by the SEE score.
+  // Try good captures ordered by MVV/LVA, then non-captures if destination square
+  // is not under attack, ordered by history value, then bad-captures and quiet
+  // moves with a negative SEE. This last group is ordered by the SEE score.
   Move m;
   int seeScore;
 
-  // Skip if we don't have at least two moves to order
   if (lastMove < moves + 2)
       return;
 
@@ -290,71 +200,119 @@ void MovePicker::score_evasions() {
       if ((seeScore = pos.see_sign(m)) < 0)
           cur->score = seeScore - History::MaxValue; // Be sure we are at the bottom
       else if (pos.is_capture(m))
-          cur->score =  piece_value_midgame(pos.piece_on(move_to(m)))
-                      - type_of(pos.piece_on(move_from(m))) + History::MaxValue;
+          cur->score =  PieceValue[Mg][pos.piece_on(to_sq(m))]
+                      - type_of(pos.piece_moved(m)) + History::MaxValue;
       else
-          cur->score = H.value(pos.piece_on(move_from(m)), move_to(m));
+          cur->score = H.value(pos.piece_moved(m), to_sq(m));
+  }
+}
+
+
+/// MovePicker::generate_next() generates, scores and sorts the next bunch of moves,
+/// when there are no more moves to try for the current phase.
+
+void MovePicker::generate_next() {
+
+  curMove = moves;
+
+  switch (++phase) {
+
+  case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6:
+      lastMove = generate<CAPTURES>(pos, moves);
+      score_captures();
+      return;
+
+  case KILLERS_S1:
+      curMove = killers;
+      lastMove = curMove + 2;
+      return;
+
+  case QUIETS_1_S1:
+      lastQuiet = lastMove = generate<QUIETS>(pos, moves);
+      score_noncaptures();
+      lastMove = std::partition(curMove, lastMove, has_positive_score);
+      sort<MoveStack>(curMove, lastMove);
+      return;
+
+  case QUIETS_2_S1:
+      curMove = lastMove;
+      lastMove = lastQuiet;
+      if (depth >= 3 * ONE_PLY)
+          sort<MoveStack>(curMove, lastMove);
+      return;
+
+  case BAD_CAPTURES_S1:
+      // Just pick them in reverse order to get MVV/LVA ordering
+      curMove = moves + MAX_MOVES - 1;
+      lastMove = lastBadCapture;
+      return;
+
+  case EVASIONS_S2:
+      lastMove = generate<EVASIONS>(pos, moves);
+      score_evasions();
+      return;
+
+  case QUIET_CHECKS_S3:
+      lastMove = generate<QUIET_CHECKS>(pos, moves);
+      return;
+
+  case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE:
+      phase = STOP;
+  case STOP:
+      lastMove = curMove + 1; // Avoid another next_phase() call
+      return;
+
+  default:
+      assert(false);
   }
 }
 
-/// MovePicker::get_next_move() is the most important method of the MovePicker
-/// class. It returns a new pseudo legal move every time it is called, until there
+
+/// MovePicker::next_move() is the most important method of the MovePicker class.
+/// It returns a new pseudo legal move every time it is called, until there
 /// are no more moves left. It picks the move with the biggest score from a list
 /// of generated moves taking care not to return the tt move if has already been
-/// searched previously. Note that this function is not thread safe so should be
-/// lock protected by caller when accessed through a shared MovePicker object.
-
-Move MovePicker::get_next_move() {
+/// searched previously.
+template<>
+Move MovePicker::next_move<false>() {
 
   Move move;
 
   while (true)
   {
       while (curMove == lastMove)
-          go_next_phase();
+          generate_next();
 
       switch (phase) {
 
-      case PH_TT_MOVE:
+      case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT:
           curMove++;
           return ttMove;
-          break;
 
-      case PH_GOOD_CAPTURES:
+      case CAPTURES_S1:
           move = pick_best(curMove++, lastMove)->move;
           if (move != ttMove)
           {
-              assert(captureThreshold <= 0); // Otherwise we must use see instead of see_sign
+              assert(captureThreshold <= 0); // Otherwise we cannot use see_sign()
 
-              // Check for a non negative SEE now
-              int seeValue = pos.see_sign(move);
-              if (seeValue >= captureThreshold)
+              if (pos.see_sign(move) >= captureThreshold)
                   return move;
 
               // Losing capture, move it to the tail of the array
-              (--badCaptures)->move = move;
-              badCaptures->score = seeValue;
+              (lastBadCapture--)->move = move;
           }
           break;
 
-     case PH_GOOD_PROBCUT:
-          move = pick_best(curMove++, lastMove)->move;
-          if (   move != ttMove
-              && pos.see(move) > captureThreshold)
-              return move;
-          break;
-
-      case PH_KILLERS:
+      case KILLERS_S1:
           move = (curMove++)->move;
-          if (   move != MOVE_NONE
-              && pos.is_pseudo_legal(move)
-              && move != ttMove
+          if (    move != MOVE_NONE
+              &&  pos.is_pseudo_legal(move)
+              &&  move != ttMove
               && !pos.is_capture(move))
               return move;
           break;
 
-      case PH_NONCAPTURES_1:
-      case PH_NONCAPTURES_2:
+      case QUIETS_1_S1: case QUIETS_2_S1:
           move = (curMove++)->move;
           if (   move != ttMove
               && move != killers[0].move
@@ -362,35 +320,45 @@ Move MovePicker::get_next_move() {
               return move;
           break;
 
-      case PH_BAD_CAPTURES:
-          move = pick_best(curMove++, lastMove)->move;
-          return move;
+      case BAD_CAPTURES_S1:
+          return (curMove--)->move;
 
-      case PH_EVASIONS:
-      case PH_QCAPTURES:
+      case EVASIONS_S2: case CAPTURES_S3: case CAPTURES_S4:
           move = pick_best(curMove++, lastMove)->move;
           if (move != ttMove)
               return move;
           break;
 
-      case PH_QRECAPTURES:
-          move = (curMove++)->move;
-          if (move_to(move) == recaptureSquare)
+      case CAPTURES_S5:
+           move = pick_best(curMove++, lastMove)->move;
+           if (move != ttMove && pos.see(move) > captureThreshold)
+               return move;
+           break;
+
+      case CAPTURES_S6:
+          move = pick_best(curMove++, lastMove)->move;
+          if (to_sq(move) == recaptureSquare)
               return move;
           break;
 
-      case PH_QCHECKS:
+      case QUIET_CHECKS_S3:
           move = (curMove++)->move;
           if (move != ttMove)
               return move;
           break;
 
-      case PH_STOP:
+      case STOP:
           return MOVE_NONE;
 
       default:
           assert(false);
-          break;
       }
   }
 }
+
+
+/// Version of next_move() to use at split point nodes where the move is grabbed
+/// from the split point's shared MovePicker object. This function is not thread
+/// safe so should be lock protected by the caller.
+template<>
+Move MovePicker::next_move<true>() { return ss->sp->mp->next_move<false>(); }