X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitbase.cpp;h=27bf4095478db4bfc9209c660b124a984d243887;hb=b82d93ece484f833c994b40d9eddd959ba20ef92;hp=be6f0d0afd31d78a10ce6f46d002cf348c7371e2;hpb=a5e3b4eddede900c1df610e8e25026a79d706500;p=stockfish

diff --git a/src/bitbase.cpp b/src/bitbase.cpp
index be6f0d0a..27bf4095 100644
--- a/src/bitbase.cpp
+++ b/src/bitbase.cpp
@@ -1,8 +1,6 @@
 /*
   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) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -25,6 +23,8 @@
 #include "bitboard.h"
 #include "types.h"
 
+namespace Stockfish {
+
 namespace {
 
   // There are 24 possible pawn squares: files A to D and ranks from 2 to 7.
@@ -68,7 +68,6 @@ namespace {
 
 } // namespace
 
-
 bool Bitbases::probe(Square wksq, Square wpsq, Square bksq, Color stm) {
 
   assert(file_of(wpsq) <= FILE_D);
@@ -98,7 +97,6 @@ void Bitbases::init() {
           KPKBitbase.set(idx);
 }
 
-
 namespace {
 
   KPKPosition::KPKPosition(unsigned idx) {
@@ -108,25 +106,25 @@ namespace {
     stm        = Color ((idx >> 12) & 0x01);
     psq        = make_square(File((idx >> 13) & 0x3), Rank(RANK_7 - ((idx >> 15) & 0x7)));
 
-    // Check if two pieces are on the same square or if a king can be captured
+    // Invalid if two pieces are on the same square or if a king can be captured
     if (   distance(ksq[WHITE], ksq[BLACK]) <= 1
         || ksq[WHITE] == psq
         || ksq[BLACK] == psq
         || (stm == WHITE && (pawn_attacks_bb(WHITE, psq) & ksq[BLACK])))
         result = INVALID;
 
-    // Immediate win if a pawn can be promoted without getting captured
+    // Win if the pawn can be promoted without getting captured
     else if (   stm == WHITE
              && rank_of(psq) == RANK_7
-             && ksq[stm] != psq + NORTH
-             && (    distance(ksq[~stm], psq + NORTH) > 1
-                 || (attacks_bb<KING>(ksq[stm]) & (psq + NORTH))))
+             && ksq[WHITE] != psq + NORTH
+             && (    distance(ksq[BLACK], psq + NORTH) > 1
+                 || (distance(ksq[WHITE], psq + NORTH) == 1)))
         result = WIN;
 
-    // Immediate draw if it is a stalemate or a king captures undefended pawn
+    // Draw if it is stalemate or the black king can capture the pawn
     else if (   stm == BLACK
-             && (  !(attacks_bb<KING>(ksq[stm]) & ~(attacks_bb<KING>(ksq[~stm]) | pawn_attacks_bb(~stm, psq)))
-                 || (attacks_bb<KING>(ksq[stm]) & psq & ~attacks_bb<KING>(ksq[~stm]))))
+             && (  !(attacks_bb<KING>(ksq[BLACK]) & ~(attacks_bb<KING>(ksq[WHITE]) | pawn_attacks_bb(WHITE, psq)))
+                 || (attacks_bb<KING>(ksq[BLACK]) & ~attacks_bb<KING>(ksq[WHITE]) & psq)))
         result = DRAW;
 
     // Position will be classified later
@@ -152,8 +150,8 @@ namespace {
     Bitboard b = attacks_bb<KING>(ksq[stm]);
 
     while (b)
-        r |= stm == WHITE ? db[index(BLACK, ksq[BLACK] , pop_lsb(&b), psq)]
-                          : db[index(WHITE, pop_lsb(&b),  ksq[WHITE], psq)];
+        r |= stm == WHITE ? db[index(BLACK, ksq[BLACK], pop_lsb(b), psq)]
+                          : db[index(WHITE, pop_lsb(b), ksq[WHITE], psq)];
 
     if (stm == WHITE)
     {
@@ -170,3 +168,5 @@ namespace {
   }
 
 } // namespace
+
+} // namespace Stockfish