X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fpawns.cpp;h=c20cb5293c009ee2a2538318965be79156ba5d4b;hb=d940e59dad51e78d5146bb21c8f792379df64816;hp=04222a2aa4ee98544afd22d193850c5012fa5ba4;hpb=97a0e4e8170df33b927c48d734e0132e9ef8a22f;p=stockfish

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 04222a2a..c20cb529 100644
--- 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) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 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
@@ -32,12 +32,13 @@ namespace {
   #define S(mg, eg) make_score(mg, eg)
 
   // Pawn penalties
-  constexpr Score Backward      = S( 9, 24);
-  constexpr Score BlockedStorm  = S(82, 82);
-  constexpr Score Doubled       = S(11, 56);
-  constexpr Score Isolated      = S( 5, 15);
-  constexpr Score WeakLever     = S( 0, 56);
-  constexpr Score WeakUnopposed = S(13, 27);
+  constexpr Score Backward        = S( 9, 24);
+  constexpr Score BlockedStorm    = S(82, 82);
+  constexpr Score Doubled         = S(11, 56);
+  constexpr Score DoubledIsolated = S(15, 57);
+  constexpr Score Isolated        = S( 5, 15);
+  constexpr Score WeakLever       = S( 0, 56);
+  constexpr Score WeakUnopposed   = S(13, 27);
 
   // Connected pawn bonus
   constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
@@ -68,7 +69,7 @@ namespace {
   template<Color Us>
   Score evaluate(const Position& pos, Pawns::Entry* e) {
 
-    constexpr Color     Them = (Us == WHITE ? BLACK : WHITE);
+    constexpr Color     Them = ~Us;
     constexpr Direction Up   = pawn_push(Us);
 
     Bitboard neighbours, stoppers, support, phalanx, opposed;
@@ -105,6 +106,8 @@ namespace {
         phalanx    = neighbours & rank_bb(s);
         support    = neighbours & rank_bb(s - Up);
 
+        e->blockedCount += blocked || more_than_one(leverPush);
+
         // A pawn is backward when it is behind all pawns of the same color on
         // the adjacent files and cannot safely advance.
         backward =  !(neighbours & forward_ranks_bb(Them, s + Up))
@@ -118,12 +121,15 @@ namespace {
         // (a) there is no stoppers except some levers
         // (b) the only stoppers are the leverPush, but we outnumber them
         // (c) there is only one front stopper which can be levered.
+        //     (Refined in Evaluation::passed)
         passed =   !(stoppers ^ lever)
                 || (   !(stoppers ^ leverPush)
                     && popcount(phalanx) >= popcount(leverPush))
                 || (   stoppers == blocked && r >= RANK_5
                     && (shift<Up>(support) & ~(theirPawns | doubleAttackThem)));
 
+        passed &= !(forward_file_bb(Us, s) & ourPawns);
+
         // Passed pawns will be properly scored later in evaluation when we have
         // full attack info.
         if (passed)
@@ -132,16 +138,23 @@ namespace {
         // Score this pawn
         if (support | phalanx)
         {
-            int v =  Connected[r] * (2 + bool(phalanx) - bool(opposed))
+            int v =  Connected[r] * (4 + 2 * bool(phalanx) - 2 * bool(opposed) - bool(blocked)) / 2
                    + 21 * popcount(support);
 
             score += make_score(v, v * (r - 2) / 4);
         }
 
         else if (!neighbours)
+        {
             score -=   Isolated
                      + WeakUnopposed * !opposed;
 
+            if (   (ourPawns & forward_file_bb(Them, s))
+                && popcount(opposed) == 1
+                && !(theirPawns & adjacent_files_bb(s)))
+                score -= DoubledIsolated;
+        }
+
         else if (backward)
             score -=   Backward
                      + WeakUnopposed * !opposed;
@@ -172,6 +185,7 @@ Entry* probe(const Position& pos) {
       return e;
 
   e->key = key;
+  e->blockedCount = 0;
   e->scores[WHITE] = evaluate<WHITE>(pos, e);
   e->scores[BLACK] = evaluate<BLACK>(pos, e);
 
@@ -185,7 +199,7 @@ Entry* probe(const Position& pos) {
 template<Color Us>
 Score Entry::evaluate_shelter(const Position& pos, Square ksq) {
 
-  constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+  constexpr Color Them = ~Us;
 
   Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
   Bitboard ourPawns = b & pos.pieces(Us);
@@ -193,7 +207,7 @@ Score Entry::evaluate_shelter(const Position& pos, Square ksq) {
 
   Score bonus = make_score(5, 5);
 
-  File center = clamp(file_of(ksq), FILE_B, FILE_G);
+  File center = Utility::clamp(file_of(ksq), FILE_B, FILE_G);
   for (File f = File(center - 1); f <= File(center + 1); ++f)
   {
       b = ourPawns & file_bb(f);
@@ -202,7 +216,7 @@ Score Entry::evaluate_shelter(const Position& pos, Square ksq) {
       b = theirPawns & file_bb(f);
       int theirRank = b ? relative_rank(Us, frontmost_sq(Them, b)) : 0;
 
-      File d = map_to_queenside(f);
+      File d = File(edge_distance(f));
       bonus += make_score(ShelterStrength[d][ourRank], 0);
 
       if (ourRank && (ourRank == theirRank - 1))
@@ -238,7 +252,7 @@ Score Entry::do_king_safety(const Position& pos) {
 
   // In endgame we like to bring our king near our closest pawn
   Bitboard pawns = pos.pieces(Us, PAWN);
-  int minPawnDist = pawns ? 8 : 0;
+  int minPawnDist = 6;
 
   if (pawns & PseudoAttacks[KING][ksq])
       minPawnDist = 1;