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Small eval cleanup and renaming
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Non-functional changes

a) splitting the threat array to avoid using an enum
b) reorder the scores according to functions where they are used.
c) declarations in evaluate_pieces after the const(s) like elsewhere
d) more compact definitions of KingFlank,
now that we need it also for the PanwLessFlank penalty.
e) reuse CenterFiles in evaluate_space
f) move one line inside next popcount

No functional change.
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@Rocky640 @mcostalba
Rocky640 authored and mcostalba committed Dec 31, 2016
1 parent ab4f498 commit 43f6b33
Showing 1 changed file with 35 additions and 39 deletions.
74 changes: 35 additions & 39 deletions src/evaluate.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -159,15 +159,18 @@ namespace {
S(0, 0), S(0, 0), S(176, 139), S(131, 127), S(217, 218), S(203, 215)
};

// Threat[by minor/by rook][attacked PieceType] contains
// bonuses according to which piece type attacks which one.
// Attacks on lesser pieces which are pawn-defended are not considered.
const Score Threat[][PIECE_TYPE_NB] = {
{ S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72,107), S(48,118) }, // by Minor
{ S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48) } // by Rook
// ThreatByMinor/ByRook[attacked PieceType] contains bonuses according to
// which piece type attacks which one. Attacks on lesser pieces which are
// pawn-defended are not considered.
const Score ThreatByMinor[PIECE_TYPE_NB] = {
S(0, 0), S(0, 33), S(45, 43), S(46, 47), S(72, 107), S(48, 118)
};

// ThreatByKing[on one/on many] contains bonuses for King attacks on
const Score ThreatByRook[PIECE_TYPE_NB] = {
S(0, 0), S(0, 25), S(40, 62), S(40, 59), S( 0, 34), S(35, 48)
};

// ThreatByKing[on one/on many] contains bonuses for king attacks on
// pawns or pieces which are not pawn-defended.
const Score ThreatByKing[2] = { S(3, 62), S(9, 138) };

Expand All @@ -181,24 +184,24 @@ namespace {
// PassedFile[File] contains a bonus according to the file of a passed pawn
const Score PassedFile[FILE_NB] = {
S( 9, 10), S( 2, 10), S( 1, -8), S(-20,-12),
S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10)
S(-20,-12), S( 1, -8), S( 2, 10), S( 9, 10)
};

// Assorted bonuses and penalties used by evaluation
const Score MinorBehindPawn = S(16, 0);
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 WeakQueen = S(50, 10);
const Score OtherCheck = S(10, 10);
const Score ThreatByHangingPawn = S(71, 61);
const Score CloseEnemies = S( 7, 0);
const Score PawnlessFlank = S(20, 80);
const Score LooseEnemies = S( 0, 25);
const Score WeakQueen = S(50, 10);
const Score ThreatByHangingPawn = S(71, 61);
const Score ThreatByRank = S(16, 3);
const Score Hanging = S(48, 27);
const Score ThreatByPawnPush = S(38, 22);
const Score PawnlessFlank = S(20, 80);
const Score HinderPassedPawn = S( 7, 0);
const Score ThreatByRank = S(16, 3);

// Penalty for a bishop on a1/h1 (a8/h8 for black) which is trapped by
// a friendly pawn on b2/g2 (b7/g7 for black). This can obviously only
Expand Down Expand Up @@ -238,8 +241,7 @@ namespace {
if (pos.non_pawn_material(Us) >= QueenValueMg)
{
ei.kingRing[Them] = b | shift<Down>(b);
b &= ei.attackedBy[Us][PAWN];
ei.kingAttackersCount[Us] = popcount(b);
ei.kingAttackersCount[Us] = popcount(b & ei.attackedBy[Us][PAWN]);
ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
}
else
Expand All @@ -253,16 +255,16 @@ namespace {
template<bool DoTrace, Color Us = WHITE, PieceType Pt = KNIGHT>
Score evaluate_pieces(const Position& pos, EvalInfo& ei, Score* mobility,
const Bitboard* mobilityArea) {
Bitboard b, bb;
Square s;
Score score = SCORE_ZERO;

const PieceType NextPt = (Us == WHITE ? Pt : PieceType(Pt + 1));
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Bitboard OutpostRanks = (Us == WHITE ? Rank4BB | Rank5BB | Rank6BB
: Rank5BB | Rank4BB | Rank3BB);
const Square* pl = pos.squares<Pt>(Us);

Bitboard b, bb;
Square s;
Score score = SCORE_ZERO;

ei.attackedBy[Us][Pt] = 0;

while ((s = *pl++) != SQ_NONE)
Expand Down Expand Up @@ -376,28 +378,24 @@ 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 },
const Bitboard KingFlank[FILE_NB] = {
CenterFiles >> 2, CenterFiles >> 2, CenterFiles >> 2, CenterFiles, CenterFiles,
CenterFiles << 2, CenterFiles << 2, CenterFiles << 2
};

template<Color Us, bool DoTrace>
Score evaluate_king(const Position& pos, const EvalInfo& ei) {

const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square Up = (Us == WHITE ? NORTH : SOUTH);
const Color Them = (Us == WHITE ? BLACK : WHITE);
const Square Up = (Us == WHITE ? NORTH : SOUTH);
const Bitboard Camp = (Us == WHITE ? ~Bitboard(0) ^ Rank6BB ^ Rank7BB ^ Rank8BB
: ~Bitboard(0) ^ Rank1BB ^ Rank2BB ^ Rank3BB);

const Square ksq = pos.square<KING>(Us);
Bitboard undefended, b, b1, b2, safe, other;
int kingDanger;
const Square ksq = pos.square<KING>(Us);

// King shelter and enemy pawns storm
Score score = ei.pi->king_safety<Us>(pos, ksq);
Expand Down Expand Up @@ -483,7 +481,7 @@ namespace {

// King tropism: firstly, find squares that opponent attacks in our king flank
File kf = file_of(ksq);
b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[Us][kf];
b = ei.attackedBy[Them][ALL_PIECES] & KingFlank[kf] & Camp;

assert(((Us == WHITE ? b << 4 : b >> 4) & b) == 0);
assert(popcount(Us == WHITE ? b << 4 : b >> 4) == popcount(b));
Expand All @@ -496,7 +494,7 @@ namespace {
score -= CloseEnemies * popcount(b);

// Penalty when our king is on a pawnless flank
if (!(pos.pieces(PAWN) & (KingFlank[WHITE][kf] | KingFlank[BLACK][kf])))
if (!(pos.pieces(PAWN) & KingFlank[kf]))
score -= PawnlessFlank;

if (DoTrace)
Expand All @@ -519,8 +517,6 @@ namespace {
const Bitboard TRank2BB = (Us == WHITE ? Rank2BB : Rank7BB);
const Bitboard TRank7BB = (Us == WHITE ? Rank7BB : Rank2BB);

enum { Minor, Rook };

Bitboard b, weak, defended, safeThreats;
Score score = SCORE_ZERO;

Expand Down Expand Up @@ -561,7 +557,7 @@ namespace {
while (b)
{
Square s = pop_lsb(&b);
score += Threat[Minor][type_of(pos.piece_on(s))];
score += ThreatByMinor[type_of(pos.piece_on(s))];
if (type_of(pos.piece_on(s)) != PAWN)
score += ThreatByRank * (int)relative_rank(Them, s);
}
Expand All @@ -570,7 +566,7 @@ namespace {
while (b)
{
Square s = pop_lsb(&b);
score += Threat[Rook][type_of(pos.piece_on(s))];
score += ThreatByRook[type_of(pos.piece_on(s))];
if (type_of(pos.piece_on(s)) != PAWN)
score += ThreatByRank * (int)relative_rank(Them, s);
}
Expand Down Expand Up @@ -702,8 +698,8 @@ namespace {

const Color Them = (Us == WHITE ? BLACK : WHITE);
const Bitboard SpaceMask =
Us == WHITE ? (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank2BB | Rank3BB | Rank4BB)
: (FileCBB | FileDBB | FileEBB | FileFBB) & (Rank7BB | Rank6BB | Rank5BB);
Us == WHITE ? CenterFiles & (Rank2BB | Rank3BB | Rank4BB)
: CenterFiles & (Rank7BB | Rank6BB | Rank5BB);

// Find the safe squares for our pieces inside the area defined by
// SpaceMask. A square is unsafe if it is attacked by an enemy
Expand Down

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