X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=c7bc8d1752f8c15e18ecf43baf1d3e0ae8f329d5;hp=639cd02a4067d1e3c3df4c30236dacb44234a729;hb=ad43ce143664953087b44dd3b4324f77c212bd46;hpb=b5f6c2241b3ad688fb85ea8203a9254aff842f07

diff --git a/src/search.cpp b/src/search.cpp
index 639cd02a..c7bc8d17 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -190,7 +190,7 @@ namespace {
     MovePickerExt(const Position& p, Move ttm, Depth d, const History& h, Stack* ss, Value b)
                   : MovePicker(p, ttm, d, h, ss, b), mp(ss->sp->mp) {}
 
-    Move get_next_move() { return mp->get_next_move(); }
+    Move next_move() { return mp->next_move(); }
     MovePicker* mp;
   };
 
@@ -296,12 +296,12 @@ void Search::think() {
           || count(SearchMoves.begin(), SearchMoves.end(), ml.move()))
           RootMoves.push_back(RootMove(ml.move()));
 
-  if (Options["OwnBook"].value<bool>())
+  if (Options["OwnBook"])
   {
-      if (Options["Book File"].value<string>() != book.name())
-          book.open(Options["Book File"].value<string>());
+      if (book.name() != (string)Options["Book File"])
+          book.open(Options["Book File"]);
 
-      Move bookMove = book.probe(pos, Options["Best Book Move"].value<bool>());
+      Move bookMove = book.probe(pos, Options["Best Book Move"]);
 
       if (   bookMove != MOVE_NONE
           && count(RootMoves.begin(), RootMoves.end(), bookMove))
@@ -315,24 +315,24 @@ void Search::think() {
   read_evaluation_uci_options(pos.side_to_move());
   Threads.read_uci_options();
 
-  TT.set_size(Options["Hash"].value<int>());
-  if (Options["Clear Hash"].value<bool>())
+  TT.set_size(Options["Hash"]);
+  if (Options["Clear Hash"])
   {
-      Options["Clear Hash"].set_value("false");
+      Options["Clear Hash"] = false;
       TT.clear();
   }
 
-  UCIMultiPV = Options["MultiPV"].value<size_t>();
-  SkillLevel = Options["Skill Level"].value<int>();
+  UCIMultiPV = Options["MultiPV"];
+  SkillLevel = Options["Skill Level"];
 
   // Do we have to play with skill handicap? In this case enable MultiPV that
   // we will use behind the scenes to retrieve a set of possible moves.
   SkillLevelEnabled = (SkillLevel < 20);
   MultiPV = (SkillLevelEnabled ? std::max(UCIMultiPV, (size_t)4) : UCIMultiPV);
 
-  if (Options["Use Search Log"].value<bool>())
+  if (Options["Use Search Log"])
   {
-      Log log(Options["Search Log Filename"].value<string>());
+      Log log(Options["Search Log Filename"]);
       log << "\nSearching: "  << pos.to_fen()
           << "\ninfinite: "   << Limits.infinite
           << " ponder: "      << Limits.ponder
@@ -362,11 +362,11 @@ void Search::think() {
   Threads.set_timer(0);
   Threads.set_size(1);
 
-  if (Options["Use Search Log"].value<bool>())
+  if (Options["Use Search Log"])
   {
       int e = elapsed_time();
 
-      Log log(Options["Search Log Filename"].value<string>());
+      Log log(Options["Search Log Filename"]);
       log << "Nodes: "          << pos.nodes_searched()
           << "\nNodes/second: " << (e > 0 ? pos.nodes_searched() * 1000 / e : 0)
           << "\nBest move: "    << move_to_san(pos, RootMoves[0].pv[0]);
@@ -410,10 +410,10 @@ namespace {
     bestValue = delta = -VALUE_INFINITE;
     ss->currentMove = MOVE_NULL; // Hack to skip update gains
 
-    // Handle the special case of a mate/stalemate position
+    // Handle the special case of a mated/stalemate position
     if (RootMoves.empty())
     {
-        cout << "info depth 0"
+        cout << "info depth 0 score "
              << score_to_uci(pos.in_check() ? -VALUE_MATE : VALUE_DRAW) << endl;
 
         RootMoves.push_back(MOVE_NONE);
@@ -512,7 +512,7 @@ namespace {
         if (SkillLevelEnabled && depth == 1 + SkillLevel)
             skillBest = do_skill_level();
 
-        if (Options["Use Search Log"].value<bool>())
+        if (Options["Use Search Log"])
              pv_info_to_log(pos, depth, bestValue, elapsed_time(), &RootMoves[0].pv[0]);
 
         // Filter out startup noise when monitoring best move stability
@@ -588,9 +588,9 @@ namespace {
     const bool SpNode   = (NT == SplitPointPV || NT == SplitPointNonPV || NT == SplitPointRoot);
     const bool RootNode = (NT == Root || NT == SplitPointRoot);
 
-    assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
-    assert(beta > alpha && beta <= VALUE_INFINITE);
-    assert(PvNode || alpha == beta - 1);
+    assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
+    assert(PvNode == (alpha != beta - 1));
+    assert(depth > DEPTH_ZERO);
     assert(pos.thread() >= 0 && pos.thread() < Threads.size());
 
     Move movesSearched[MAX_MOVES];
@@ -640,11 +640,16 @@ namespace {
          || ss->ply > PLY_MAX) && !RootNode)
         return VALUE_DRAW;
 
-    // Step 3. Mate distance pruning
+    // Step 3. Mate distance pruning. Even if we mate at the next move our score
+    // would be at best mate_in(ss->ply+1), but if alpha is already bigger because
+    // a shorter mate was found upward in the tree then there is no need to search
+    // further, we will never beat current alpha. Same logic but with reversed signs
+    // applies also in the opposite condition of being mated instead of giving mate,
+    // in this case return a fail-high score.
     if (!RootNode)
     {
-        alpha = std::max(value_mated_in(ss->ply), alpha);
-        beta = std::min(value_mate_in(ss->ply+1), beta);
+        alpha = std::max(mated_in(ss->ply), alpha);
+        beta = std::min(mate_in(ss->ply+1), beta);
         if (alpha >= beta)
             return alpha;
     }
@@ -653,7 +658,7 @@ namespace {
     // We don't want the score of a partial search to overwrite a previous full search
     // TT value, so we use a different position key in case of an excluded move.
     excludedMove = ss->excludedMove;
-    posKey = excludedMove ? pos.get_exclusion_key() : pos.get_key();
+    posKey = excludedMove ? pos.exclusion_key() : pos.key();
     tte = TT.probe(posKey);
     ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE;
 
@@ -701,7 +706,7 @@ namespace {
     if (   (move = (ss-1)->currentMove) != MOVE_NULL
         && (ss-1)->eval != VALUE_NONE
         && ss->eval != VALUE_NONE
-        && pos.captured_piece_type() == PIECE_TYPE_NONE
+        && pos.captured_piece_type() == NO_PIECE_TYPE
         && !is_special(move))
     {
         Square to = move_to(move);
@@ -816,7 +821,7 @@ namespace {
         MovePicker mp(pos, ttMove, H, pos.captured_piece_type());
         CheckInfo ci(pos);
 
-        while ((move = mp.get_next_move()) != MOVE_NONE)
+        while ((move = mp.next_move()) != MOVE_NONE)
             if (pos.pl_move_is_legal(move, ci.pinned))
             {
                 pos.do_move(move, st, ci, pos.move_gives_check(move, ci));
@@ -867,7 +872,7 @@ split_point_start: // At split points actual search starts from here
     // Step 11. Loop through moves
     // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
     while (   bestValue < beta
-           && (move = mp.get_next_move()) != MOVE_NONE
+           && (move = mp.next_move()) != MOVE_NONE
            && !thread.cutoff_occurred())
     {
       assert(is_ok(move));
@@ -1122,7 +1127,7 @@ split_point_start: // At split points actual search starts from here
     // harmless because return value is discarded anyhow in the parent nodes.
     // If we are in a singular extension search then return a fail low score.
     if (!moveCount)
-        return excludedMove ? oldAlpha : inCheck ? value_mated_in(ss->ply) : VALUE_DRAW;
+        return excludedMove ? oldAlpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW;
 
     // If we have pruned all the moves without searching return a fail-low score
     if (bestValue == -VALUE_INFINITE)
@@ -1190,10 +1195,9 @@ split_point_start: // At split points actual search starts from here
     const bool PvNode = (NT == PV);
 
     assert(NT == PV || NT == NonPV);
-    assert(alpha >= -VALUE_INFINITE && alpha <= VALUE_INFINITE);
-    assert(beta >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
-    assert(PvNode || alpha == beta - 1);
-    assert(depth <= 0);
+    assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE);
+    assert(PvNode == (alpha != beta - 1));
+    assert(depth <= DEPTH_ZERO);
     assert(pos.thread() >= 0 && pos.thread() < Threads.size());
 
     StateInfo st;
@@ -1220,7 +1224,7 @@ split_point_start: // At split points actual search starts from here
 
     // Transposition table lookup. At PV nodes, we don't use the TT for
     // pruning, but only for move ordering.
-    tte = TT.probe(pos.get_key());
+    tte = TT.probe(pos.key());
     ttMove = (tte ? tte->move() : MOVE_NONE);
 
     if (!PvNode && tte && can_return_tt(tte, ttDepth, beta, ss->ply))
@@ -1252,7 +1256,7 @@ split_point_start: // At split points actual search starts from here
         if (bestValue >= beta)
         {
             if (!tte)
-                TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
+                TT.store(pos.key(), value_to_tt(bestValue, ss->ply), VALUE_TYPE_LOWER, DEPTH_NONE, MOVE_NONE, ss->eval, evalMargin);
 
             return bestValue;
         }
@@ -1273,7 +1277,7 @@ split_point_start: // At split points actual search starts from here
 
     // Loop through the moves until no moves remain or a beta cutoff occurs
     while (   bestValue < beta
-           && (move = mp.get_next_move()) != MOVE_NONE)
+           && (move = mp.next_move()) != MOVE_NONE)
     {
       assert(is_ok(move));
 
@@ -1366,14 +1370,14 @@ split_point_start: // At split points actual search starts from here
     // All legal moves have been searched. A special case: If we're in check
     // and no legal moves were found, it is checkmate.
     if (inCheck && bestValue == -VALUE_INFINITE)
-        return value_mated_in(ss->ply);
+        return mated_in(ss->ply); // Plies to mate from the root
 
     // Update transposition table
     move = bestValue <= oldAlpha ? MOVE_NONE : ss->bestMove;
     vt   = bestValue <= oldAlpha ? VALUE_TYPE_UPPER
          : bestValue >= beta ? VALUE_TYPE_LOWER : VALUE_TYPE_EXACT;
 
-    TT.store(pos.get_key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin);
+    TT.store(pos.key(), value_to_tt(bestValue, ss->ply), vt, ttDepth, move, ss->eval, evalMargin);
 
     assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
 
@@ -1491,8 +1495,8 @@ split_point_start: // At split points actual search starts from here
 
 
   // value_to_tt() adjusts a mate score from "plies to mate from the root" to
-  // "plies to mate from the current ply". Non-mate scores are unchanged. The
-  // function is called before storing a value to the transposition table.
+  // "plies to mate from the current position". Non-mate scores are unchanged.
+  // The function is called before storing a value to the transposition table.
 
   Value value_to_tt(Value v, int ply) {
 
@@ -1506,8 +1510,9 @@ split_point_start: // At split points actual search starts from here
   }
 
 
-  // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score from
-  // the transposition table to a mate score corrected for the current ply.
+  // value_from_tt() is the inverse of value_to_tt(): It adjusts a mate score
+  // from the transposition table (where refers to the plies to mate/be mated
+  // from current position) to "plies to mate/be mated from the root".
 
   Value value_from_tt(Value v, int ply) {
 
@@ -1602,9 +1607,9 @@ split_point_start: // At split points actual search starts from here
     static int searchStartTime;
 
     if (reset)
-        searchStartTime = get_system_time();
+        searchStartTime = system_time();
 
-    return get_system_time() - searchStartTime;
+    return system_time() - searchStartTime;
   }
 
 
@@ -1619,10 +1624,10 @@ split_point_start: // At split points actual search starts from here
 
     std::stringstream s;
 
-    if (abs(v) < VALUE_MATE - PLY_MAX * ONE_PLY)
-        s << " score cp " << int(v) * 100 / int(PawnValueMidgame); // Scale to centipawns
+    if (abs(v) < VALUE_MATE_IN_PLY_MAX)
+        s << "cp " << v * 100 / int(PawnValueMidgame);
     else
-        s << " score mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
+        s << "mate " << (v > 0 ? VALUE_MATE - v + 1 : -VALUE_MATE - v) / 2;
 
     s << (v >= beta ? " lowerbound" : v <= alpha ? " upperbound" : "");
 
@@ -1659,7 +1664,7 @@ split_point_start: // At split points actual search starts from here
 
         cout << "info depth " << d
              << " seldepth " << selDepth
-             << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
+             << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v))
              << " nodes " << pos.nodes_searched()
              << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0)
              << " time " << t
@@ -1753,7 +1758,7 @@ split_point_start: // At split points actual search starts from here
     while (m != pv)
         pos.undo_move(*--m);
 
-    Log l(Options["Search Log Filename"].value<string>());
+    Log l(Options["Search Log Filename"]);
     l << s.str() << endl;
   }
 
@@ -1768,7 +1773,7 @@ split_point_start: // At split points actual search starts from here
     static RKISS rk;
 
     // PRNG sequence should be not deterministic
-    for (int i = abs(get_system_time() % 50); i > 0; i--)
+    for (int i = abs(system_time() % 50); i > 0; i--)
         rk.rand<unsigned>();
 
     // RootMoves are already sorted by score in descending order
@@ -1821,7 +1826,7 @@ split_point_start: // At split points actual search starts from here
     pv.push_back(m);
     pos.do_move(m, *st++);
 
-    while (   (tte = TT.probe(pos.get_key())) != NULL
+    while (   (tte = TT.probe(pos.key())) != NULL
            && tte->move() != MOVE_NONE
            && pos.is_pseudo_legal(tte->move())
            && pos.pl_move_is_legal(tte->move(), pos.pinned_pieces())
@@ -1853,7 +1858,7 @@ split_point_start: // At split points actual search starts from here
     assert(pv[ply] != MOVE_NONE && pos.is_pseudo_legal(pv[ply]));
 
     do {
-        k = pos.get_key();
+        k = pos.key();
         tte = TT.probe(k);
 
         // Don't overwrite existing correct entries
@@ -1971,9 +1976,9 @@ void do_timer_event() {
   static int lastInfoTime;
   int e = elapsed_time();
 
-  if (get_system_time() - lastInfoTime >= 1000 || !lastInfoTime)
+  if (system_time() - lastInfoTime >= 1000 || !lastInfoTime)
   {
-      lastInfoTime = get_system_time();
+      lastInfoTime = system_time();
 
       dbg_print_mean();
       dbg_print_hit_rate();