Retire lever (#1378)

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index a031534d3a4fd9b75d44e8c69ac97f99d8ef9c28..ceacca82d53b8932fe8526fbbfdc97116ba3992e 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, 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
@@ -43,12 +43,6 @@ namespace {
   // Doubled pawn penalty
   const Score Doubled = S(18, 38);
 
-  // Lever bonus by rank
-  const Score Lever[RANK_NB] = {
-    S( 0,  0), S( 0,  0), S(0, 0), S(0, 0),
-    S(17, 16), S(33, 32), S(0, 0), S(0, 0)
-  };
-
   // Weakness of our pawn shelter in front of the king by [isKingFile][distance from edge][rank].
   // RANK_1 = 0 is used for files where we have no pawns or our pawn is behind our king.
   const Value ShelterWeakness[][int(FILE_NB) / 2][RANK_NB] = {
@@ -94,10 +88,10 @@ namespace {
   template<Color Us>
   Score evaluate(const Position& pos, Pawns::Entry* e) {
 
-    const Color  Them  = (Us == WHITE ? BLACK      : WHITE);
-    const Square Up    = (Us == WHITE ? NORTH      : SOUTH);
-    const Square Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
-    const Square Left  = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
+    const Color     Them  = (Us == WHITE ? BLACK      : WHITE);
+    const Direction Up    = (Us == WHITE ? NORTH      : SOUTH);
+    const Direction Right = (Us == WHITE ? NORTH_EAST : SOUTH_WEST);
+    const Direction Left  = (Us == WHITE ? NORTH_WEST : SOUTH_EAST);
 
     Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
     Bitboard lever, leverPush;
@@ -184,9 +178,6 @@ namespace {
 
         if (doubled && !supported)
             score -= Doubled;
-
-        if (lever)
-            score += Lever[relative_rank(Us, s)];
     }
 
     return score;
@@ -254,7 +245,7 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) {
   Value safety = MaxSafetyBonus;
   File center = std::max(FILE_B, std::min(FILE_G, file_of(ksq)));
 
-  for (File f = center - File(1); f <= center + File(1); ++f)
+  for (File f = File(center - 1); f <= File(center + 1); ++f)
   {
       b = ourPawns & file_bb(f);
       Rank rkUs = b ? relative_rank(Us, backmost_sq(Us, b)) : RANK_1;
@@ -262,7 +253,7 @@ Value Entry::shelter_storm(const Position& pos, Square ksq) {
       b = theirPawns & file_bb(f);
       Rank rkThem = b ? relative_rank(Us, frontmost_sq(Them, b)) : RANK_1;
 
-      int d = std::min(f, FILE_H - f);
+      int d = std::min(f, ~f);
       safety -=  ShelterWeakness[f == file_of(ksq)][d][rkUs]
                + StormDanger
                  [f == file_of(ksq) && rkThem == relative_rank(Us, ksq) + 1 ? BlockedByKing  :