Merge pull request #5 from glinscott/authors

Add AUTHORS

diff --git a/src/material.cpp b/src/material.cpp
index 9a120661eb249306d1a52994a4485ea1b6bf60f9..b7db134b9aa35d0a43dae7d4355f71af34a65327 100644 (file)
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -29,10 +29,10 @@ namespace {
 
   // Polynomial material balance parameters
 
-  //                                  pair  pawn knight bishop rook queen
-  const int LinearCoefficients[6] = { 1852, -162, -1122, -183,  249, -154 };
+  //                      pair  pawn knight bishop rook queen
+  const int Linear[6] = { 1852, -162, -1122, -183,  249, -154 };
 
-  const int QuadraticCoefficientsSameSide[][PIECE_TYPE_NB] = {
+  const int QuadraticSameSide[][PIECE_TYPE_NB] = {
     //            OUR PIECES
     // pair pawn knight bishop rook queen
     {   0                               }, // Bishop pair
@@ -43,7 +43,7 @@ namespace {
     {-177,   25, 129,   142,  -137,   0 }  // Queen
   };
 
-  const int QuadraticCoefficientsOppositeSide[][PIECE_TYPE_NB] = {
+  const int QuadraticOppositeSide[][PIECE_TYPE_NB] = {
     //           THEIR PIECES
     // pair pawn knight bishop rook queen
     {   0                               }, // Bishop pair
@@ -66,8 +66,7 @@ namespace {
   // Helper templates used to detect a given material distribution
   template<Color Us> bool is_KXK(const Position& pos) {
     const Color Them = (Us == WHITE ? BLACK : WHITE);
-    return  !pos.count<PAWN>(Them)
-          && pos.non_pawn_material(Them) == VALUE_ZERO
+    return  !more_than_one(pos.pieces(Them))
           && pos.non_pawn_material(Us) >= RookValueMg;
   }
 
@@ -94,26 +93,24 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    int pt1, pt2, pc, v;
-    int value = 0;
+    int bonus = 0;
 
     // Second-degree polynomial material imbalance by Tord Romstad
-    for (pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
+    for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
     {
-        pc = pieceCount[Us][pt1];
-        if (!pc)
+        if (!pieceCount[Us][pt1])
             continue;
 
-        v = LinearCoefficients[pt1];
+        int v = Linear[pt1];
 
-        for (pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
-            v +=  QuadraticCoefficientsSameSide[pt1][pt2] * pieceCount[Us][pt2]
-                + QuadraticCoefficientsOppositeSide[pt1][pt2] * pieceCount[Them][pt2];
+        for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
+            v +=  QuadraticSameSide[pt1][pt2] * pieceCount[Us][pt2]
+                + QuadraticOppositeSide[pt1][pt2] * pieceCount[Them][pt2];
 
-        value += pc * v;
+        bonus += pieceCount[Us][pt1] * v;
     }
 
-    return value;
+    return bonus;
   }
 
 } // namespace
@@ -139,7 +136,7 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
   std::memset(e, 0, sizeof(Entry));
   e->key = key;
   e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
-  e->gamePhase = game_phase(pos);
+  e->gamePhase = pos.game_phase();
 
   // Let's look if we have a specialized evaluation function for this particular
   // material configuration. Firstly we look for a fixed configuration one, then
@@ -248,18 +245,4 @@ Entry* probe(const Position& pos, Table& entries, Endgames& endgames) {
   return e;
 }
 
-
-/// Material::game_phase() calculates the phase given the current
-/// position. Because the phase is strictly a function of the material, it
-/// is stored in MaterialEntry.
-
-Phase game_phase(const Position& pos) {
-
-  Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
-
-  return  npm >= MidgameLimit ? PHASE_MIDGAME
-        : npm <= EndgameLimit ? PHASE_ENDGAME
-        : Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
-}
-
 } // namespace Material

diff --git a/src/material.h b/src/material.h
index 91163610e708ce7c1bbd4e222f7f6115dee60f57..f05541cc3b24e6fd52c1c9265ce69d09048ecdd6 100644 (file)
--- a/src/material.h
+++ b/src/material.h
@@ -68,7 +68,6 @@ struct Entry {
 typedef HashTable<Entry, 8192> Table;
 
 Entry* probe(const Position& pos, Table& entries, Endgames& endgames);
-Phase game_phase(const Position& pos);
 
 } // namespace Material
 

diff --git a/src/pawns.cpp b/src/pawns.cpp
index aa3139e27a7b65fe7af7b986437134d93e0ca5de..4d878e2063419a590e3a18a3633c1b75444820fa 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -57,7 +57,7 @@ namespace {
     S( 0, 0), S( 6, 13), S(6,13), S(14,29),
     S(34,68), S(83,166), S(0, 0), S( 0, 0) };
 
-    // Levers bonus by rank
+  // Levers bonus by rank
   const Score Lever[RANK_NB] = {
     S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
     S(20,20), S(40,40), S(0, 0), S(0, 0) };
@@ -74,7 +74,7 @@ namespace {
 
   // Danger of enemy pawns moving toward our king indexed by
   // [no friendly pawn | pawn unblocked | pawn blocked][rank of enemy pawn]
-  const Value StormDanger[3][RANK_NB] = {
+  const Value StormDanger[][RANK_NB] = {
   { V( 0),  V(64), V(128), V(51), V(26) },
   { V(26),  V(32), V( 96), V(38), V(20) },
   { V( 0),  V( 0), V(160), V(25), V(13) } };
@@ -223,20 +223,19 @@ namespace Pawns {
 
 void init() {
 
-  const int bonusesByFile[8] = { 1, 3, 3, 4, 4, 3, 3, 1 };
-  int bonus;
+  const int bonusByFile[] = { 1, 3, 3, 4, 4, 3, 3, 1 };
 
   for (Rank r = RANK_1; r < RANK_8; ++r)
       for (File f = FILE_A; f <= FILE_H; ++f)
       {
-          bonus = r * (r-1) * (r-2) + bonusesByFile[f] * (r/2 + 1);
+          int bonus = r * (r - 1) * (r - 2) + bonusByFile[f] * (r / 2 + 1);
           Connected[f][r] = make_score(bonus, bonus);
       }
 }
 
 
-/// probe() takes a position object as input, computes a Entry object, and returns
-/// a pointer to it. The result is also stored in a hash table, so we don't have
+/// probe() takes a position as input, computes a Entry object, and returns a
+/// pointer to it. The result is also stored in a hash table, so we don't have
 /// to recompute everything when the same pawn structure occurs again.
 
 Entry* probe(const Position& pos, Table& entries) {
@@ -260,30 +259,30 @@ template<Color Us>
 Value Entry::shelter_storm(const Position& pos, Square ksq) {
 
   const Color Them = (Us == WHITE ? BLACK : WHITE);
-  static const Bitboard MiddleEdges = (FileABB | FileHBB) & (Rank2BB | Rank3BB);
+  const Bitboard Edges = (FileABB | FileHBB) & (Rank2BB | Rank3BB);
 
-  Value safety = MaxSafetyBonus;
   Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq));
   Bitboard ourPawns = b & pos.pieces(Us);
   Bitboard theirPawns = b & pos.pieces(Them);
-  Rank rkUs, rkThem;
+  Value safety = MaxSafetyBonus;
   File kf = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
 
   for (File f = kf - File(1); f <= kf + File(1); ++f)
   {
       b = ourPawns & file_bb(f);
-      rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
+      Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
 
       b  = theirPawns & file_bb(f);
-      rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
+      Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
 
-      if (   (MiddleEdges & make_square(f, rkThem))
+      if (   (Edges & make_square(f, rkThem))
           && file_of(ksq) == f
           && relative_rank(Us, ksq) == rkThem - 1)
           safety += 200;
       else
-          safety -= ShelterWeakness[rkUs]
-                  + StormDanger[rkUs == RANK_1 ? 0 : rkThem == rkUs + 1 ? 2 : 1][rkThem];
+          safety -=  ShelterWeakness[rkUs]
+                   + StormDanger[rkUs   == RANK_1   ? 0 :
+                                 rkThem != rkUs + 1 ? 1 : 2][rkThem];
   }
 
   return safety;

diff --git a/src/position.cpp b/src/position.cpp
index 2d5119389b989c0719c1514dd330ad7ddbeeca81..bdbfea8017583fe3b8ca432738bc54a6dec886af 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -465,6 +465,19 @@ const string Position::pretty(Move m) const {
 }
 
 
+/// Position::game_phase() calculates the game phase interpolating total non-pawn
+/// material between endgame and midgame limits.
+
+Phase Position::game_phase() const {
+
+  Value npm = st->npMaterial[WHITE] + st->npMaterial[BLACK];
+
+  npm = std::max(EndgameLimit, std::min(npm, MidgameLimit));
+
+  return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
+}
+
+
 /// Position::check_blockers() returns a bitboard of all the pieces with color
 /// 'c' that are blocking check on the king with color 'kingColor'. A piece
 /// blocks a check if removing that piece from the board would result in a

diff --git a/src/position.h b/src/position.h
index 0f88944c106c24ba1571decc2fa4702ed9b3657a..d950411f6fe63cfac676e83d9e748f11f4c925fd 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -156,6 +156,7 @@ public:
 
   // Other properties of the position
   Color side_to_move() const;
+  Phase game_phase() const;
   int game_ply() const;
   bool is_chess960() const;
   Thread* this_thread() const;

diff --git a/src/search.cpp b/src/search.cpp
index acd042c0a8ceb99a5f0fdaca232778c19a722718..24fde88fc0ef5c1087cb43bdfd41a87d81c35f7f 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -700,6 +700,7 @@ moves_loop: // When in check and at SpNode search starts from here
                            &&  depth >= 8 * ONE_PLY
                            &&  abs(beta) < VALUE_KNOWN_WIN
                            &&  ttMove != MOVE_NONE
+                           &&  ttValue != VALUE_NONE
                            && !excludedMove // Recursive singular search is not allowed
                            && (tte->bound() & BOUND_LOWER)
                            &&  tte->depth() >= depth - 3 * ONE_PLY;
@@ -766,8 +767,6 @@ moves_loop: // When in check and at SpNode search starts from here
           && !ext
           &&  pos.legal(move, ci.pinned))
       {
-          assert(ttValue != VALUE_NONE);
-
           Value rBeta = ttValue - int(depth);
           ss->excludedMove = move;
           ss->skipNullMove = true;