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stockfish
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Move king tropism to evaluate_king 

No functional change.
pull/773/head
Alain SAVARD 2016-08-27 18:16:28 -04:00 committed by Marco Costalba
parent 1ee2838214
commit 2b57b61cb1
1 changed files with 27 additions and 25 deletions
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52
src/evaluate.cpp
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@ -188,6 +188,7 @@ namespace {
const Score BishopPawns = S( 8, 12);
const Score RookOnPawn = S( 8, 24);
const Score TrappedRook = S(92, 0);
const Score CloseEnemies = S( 7, 0);
const Score SafeCheck = S(20, 20);
const Score OtherCheck = S(10, 10);
const Score ThreatByHangingPawn = S(71, 61);
@ -379,6 +380,19 @@ namespace {
// evaluate_king() assigns bonuses and penalties to a king of a given color
const Bitboard WhiteCamp = Rank1BB | Rank2BB | Rank3BB | Rank4BB | Rank5BB;
const Bitboard BlackCamp = Rank8BB | Rank7BB | Rank6BB | Rank5BB | Rank4BB;
const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
{ QueenSide & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
CenterFiles & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp },
{ QueenSide & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
CenterFiles & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp },
};
template<Color Us, bool DoTrace>
Score evaluate_king(const Position& pos, const EvalInfo& ei) {
@ -471,6 +485,19 @@ namespace {
score -= KingDanger[std::max(std::min(attackUnits, 399), 0)];
}
// King tropism: firstly, find squares that opponent attacks in our king flank
b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[Us][file_of(ksq)];
assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0);
assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b));
// Secondly, add the squares which are attacked twice in that flank and
// which are not defended by our pawns.
b = (Us == WHITE ? b << 4 : b >> 4)
| (b & ei.attackedBy2[Them] & ~ei.attackedBy[Us][PAWN]);
score -= CloseEnemies * popcount(b);
if (DoTrace)
Trace::add(KING, Us, score);
@ -481,19 +508,6 @@ namespace {
// evaluate_threats() assigns bonuses according to the types of the attacking
// and the attacked pieces.
const Bitboard WhiteCamp = Rank1BB | Rank2BB | Rank3BB | Rank4BB | Rank5BB;
const Bitboard BlackCamp = Rank8BB | Rank7BB | Rank6BB | Rank5BB | Rank4BB;
const Bitboard QueenSide = FileABB | FileBBB | FileCBB | FileDBB;
const Bitboard CenterFiles = FileCBB | FileDBB | FileEBB | FileFBB;
const Bitboard KingSide = FileEBB | FileFBB | FileGBB | FileHBB;
const Bitboard KingFlank[COLOR_NB][FILE_NB] = {
{ QueenSide & WhiteCamp, QueenSide & WhiteCamp, QueenSide & WhiteCamp, CenterFiles & WhiteCamp,
CenterFiles & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp, KingSide & WhiteCamp },
{ QueenSide & BlackCamp, QueenSide & BlackCamp, QueenSide & BlackCamp, CenterFiles & BlackCamp,
CenterFiles & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp, KingSide & BlackCamp },
};
template<Color Us, bool DoTrace>
Score evaluate_threats(const Position& pos, const EvalInfo& ei) {
@ -571,18 +585,6 @@ namespace {
score += ThreatByPawnPush * popcount(b);
// King tropism: firstly, find squares that we attack in the enemy king flank
b = ei.attackedBy[Us][ALL_PIECES] & KingFlank[Them][file_of(pos.square<KING>(Them))];
// Secondly, add to the bitboard the squares which we attack twice in that flank
// but which are not protected by a enemy pawn. Note the trick to shift away the
// previous attack bits to the empty part of the bitboard.
b = (b & ei.attackedBy2[Us] & ~ei.attackedBy[Them][PAWN])
| (Us == WHITE ? b >> 4 : b << 4);
// Count all these squares with a single popcount
score += make_score(7 * popcount(b), 0);
if (DoTrace)
Trace::add(THREAT, Us, score);