Fix compile under Windows XP

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index c09a953b62e3a7612d53f03069266a2a00493d6d..7c5ffdc5f6adcc905a2a98adb2e5b5cd60e1e4bc 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -32,6 +32,7 @@
 #include "thread.h"
 #include "tt.h"
 #include "uci.h"
+#include "syzygy/tbprobe.h"
 
 using std::string;
 
@@ -44,14 +45,14 @@ namespace Zobrist {
   Key psq[PIECE_NB][SQUARE_NB];
   Key enpassant[FILE_NB];
   Key castling[CASTLING_RIGHT_NB];
-  Key side;
+  Key side, noPawns;
 }
 
 namespace {
 
 const string PieceToChar(" PNBRQK  pnbrqk");
 
-// min_attacker() is a helper function used by see() to locate the least
+// min_attacker() is a helper function used by see_ge() to locate the least
 // valuable attacker for the side to move, remove the attacker we just found
 // from the bitboards and scan for new X-ray attacks behind it.
 
@@ -85,7 +86,7 @@ PieceType min_attacker<KING>(const Bitboard*, Square, Bitboard, Bitboard&, Bitbo
 
 /// operator<<(Position) returns an ASCII representation of the position
 
-std::ostream& operator<<(std::ostream& os, const Position& pos) {
+std::ostream& operator<<(std::ostream& os, Position& pos) {
 
   os << "\n +---+---+---+---+---+---+---+---+\n";
 
@@ -98,11 +99,22 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) {
   }
 
   os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
-     << std::setfill('0') << std::setw(16) << pos.key() << std::dec << "\nCheckers: ";
+     << std::setfill('0') << std::setw(16) << pos.key()
+     << std::setfill(' ') << std::dec << "\nCheckers: ";
 
   for (Bitboard b = pos.checkers(); b; )
       os << UCI::square(pop_lsb(&b)) << " ";
 
+  if (    int(Tablebases::MaxCardinality) >= popcount(pos.pieces())
+      && !pos.can_castle(ANY_CASTLING))
+  {
+      Tablebases::ProbeState s1, s2;
+      Tablebases::WDLScore wdl = Tablebases::probe_wdl(pos, &s1);
+      int dtz = Tablebases::probe_dtz(pos, &s2);
+      os << "\nTablebases WDL: " << std::setw(4) << wdl << " (" << s1 << ")"
+         << "\nTablebases DTZ: " << std::setw(4) << dtz << " (" << s2 << ")";
+  }
+
   return os;
 }
 
@@ -133,6 +145,7 @@ void Position::init() {
   }
 
   Zobrist::side = rng.rand<Key>();
+  Zobrist::noPawns = rng.rand<Key>();
 }
 
 
@@ -164,8 +177,9 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th
 
    4) En passant target square (in algebraic notation). If there's no en passant
       target square, this is "-". If a pawn has just made a 2-square move, this
-      is the position "behind" the pawn. This is recorded regardless of whether
-      there is a pawn in position to make an en passant capture.
+      is the position "behind" the pawn. This is recorded only if there is a pawn
+      in position to make an en passant capture, and if there really is a pawn
+      that might have advanced two squares.
 
    5) Halfmove clock. This is the number of halfmoves since the last pawn advance
       or capture. This is used to determine if a draw can be claimed under the
@@ -242,7 +256,8 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th
   {
       st->epSquare = make_square(File(col - 'a'), Rank(row - '1'));
 
-      if (!(attackers_to(st->epSquare) & pieces(sideToMove, PAWN)))
+      if (   !(attackers_to(st->epSquare) & pieces(sideToMove, PAWN))
+          || !(pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove))))
           st->epSquare = SQ_NONE;
   }
   else
@@ -317,7 +332,8 @@ void Position::set_check_info(StateInfo* si) const {
 
 void Position::set_state(StateInfo* si) const {
 
-  si->key = si->pawnKey = si->materialKey = 0;
+  si->key = si->materialKey = 0;
+  si->pawnKey = Zobrist::noPawns;
   si->nonPawnMaterial[WHITE] = si->nonPawnMaterial[BLACK] = VALUE_ZERO;
   si->psq = SCORE_ZERO;
   si->checkersBB = attackers_to(square<KING>(sideToMove)) & pieces(~sideToMove);
@@ -357,6 +373,28 @@ void Position::set_state(StateInfo* si) const {
 }
 
 
+/// Position::set() is an overload to initialize the position object with
+/// the given endgame code string like "KBPKN". It is manily an helper to
+/// get the material key out of an endgame code. Position is not playable,
+/// indeed is even not guaranteed to be legal.
+
+Position& Position::set(const string& code, Color c, StateInfo* si) {
+
+  assert(code.length() > 0 && code.length() < 8);
+  assert(code[0] == 'K');
+
+  string sides[] = { code.substr(code.find('K', 1)),      // Weak
+                     code.substr(0, code.find('K', 1)) }; // Strong
+
+  std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
+
+  string fenStr =  sides[0] + char(8 - sides[0].length() + '0') + "/8/8/8/8/8/8/"
+                 + sides[1] + char(8 - sides[1].length() + '0') + " w - - 0 10";
+
+  return set(fenStr, false, si, nullptr);
+}
+
+
 /// Position::fen() returns a FEN representation of the position. In case of
 /// Chess960 the Shredder-FEN notation is used. This is mainly a debugging function.
 
@@ -1043,14 +1081,20 @@ bool Position::is_draw() const {
   if (st->rule50 > 99 && (!checkers() || MoveList<LEGAL>(*this).size()))
       return true;
 
-  StateInfo* stp = st;
-  for (int i = 2, e = std::min(st->rule50, st->pliesFromNull); i <= e; i += 2)
-  {
+  int e = std::min(st->rule50, st->pliesFromNull);
+
+  if (e < 4)
+    return false;
+
+  StateInfo* stp = st->previous->previous;
+
+  do {
       stp = stp->previous->previous;
 
       if (stp->key == st->key)
           return true; // Draw at first repetition
-  }
+
+  } while ((e -= 2) >= 4);
 
   return false;
 }