// Pawn storm lever bonuses by file
const int StormLeverBonus[8] = { -8, -8, -13, 0, 0, -13, -8, -8 };
+ #undef S
}
//// Functions
////
-/// Constructor
+/// PawnInfoTable c'tor and d'tor instantiated one each thread
-PawnInfoTable::PawnInfoTable(unsigned numOfEntries) {
+PawnInfoTable::PawnInfoTable(unsigned numOfEntries) : size(numOfEntries) {
- size = numOfEntries;
entries = new PawnInfo[size];
if (!entries)
{
}
-/// Destructor
-
PawnInfoTable::~PawnInfoTable() {
+
delete [] entries;
}
/// PawnInfoTable::get_pawn_info() takes a position object as input, computes
-/// a PawnInfo object, and returns a pointer to it. The result is also
-/// stored in a hash table, so we don't have to recompute everything when
-/// the same pawn structure occurs again.
+/// a PawnInfo object, and returns a pointer to it. The result is also stored
+/// in a hash table, so we don't have to recompute everything when the same
+/// pawn structure occurs again.
PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) {
template<Color Us>
Score PawnInfoTable::evaluate_pawns(const Position& pos, Bitboard ourPawns,
Bitboard theirPawns, PawnInfo* pi) {
- Square s;
+ Bitboard b;
+ Square s, s2;
File f;
- Rank r;
+ Rank r, r2;
bool passed, isolated, doubled, opposed, chain, backward, candidate;
- int bonus;
+ int bonus, v;
Score value = make_score(0, 0);
const Square* ptr = pos.piece_list_begin(Us, PAWN);
assert(pos.piece_on(s) == piece_of_color_and_type(Us, PAWN));
- // Passed, isolated or doubled pawn?
- passed = !(theirPawns & passed_pawn_mask(Us, s));
- isolated = !(ourPawns & neighboring_files_bb(s));
- doubled = ourPawns & squares_behind(Us, s);
- opposed = theirPawns & squares_in_front_of(Us, s);
-
- // We calculate kingside and queenside pawn storm
- // scores for both colors. These are used when evaluating
- // middle game positions with opposite side castling.
+ // We calculate kingside and queenside pawn storm scores for
+ // both colors. These are used when evaluating middle game
+ // positions with opposite side castling.
//
// Each pawn is given a base score given by a piece square table
// (KStormTable[] or QStormTable[]). Pawns which seem to have good
- // chances of creating an open file by exchanging itself against an
- // enemy pawn on an adjacent file gets an additional bonus.
+ // chances of creating an open file by exchanging itself against
+ // an enemy pawn on an adjacent file gets an additional bonus.
// Kingside pawn storms
bonus = KStormTable[relative_square(Us, s)];
if (f >= FILE_F)
{
- Bitboard b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
+ b = outpost_mask(Us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
while (b)
{
// Give a bonus according to the distance of the nearest enemy pawn
- Square s2 = pop_1st_bit(&b);
- int v = StormLeverBonus[f] - 2 * square_distance(s, s2);
+ s2 = pop_1st_bit(&b);
+ r2 = square_rank(s2);
+ v = StormLeverBonus[f] - 2 * rank_distance(r, r2);
// If enemy pawn has no pawn beside itself is particularly vulnerable.
// Big bonus, especially against a weakness on the rook file
bonus = QStormTable[relative_square(Us, s)];
if (f <= FILE_C)
{
- Bitboard b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
+ b = outpost_mask(Us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
while (b)
{
// Give a bonus according to the distance of the nearest enemy pawn
- Square s2 = pop_1st_bit(&b);
- int v = StormLeverBonus[f] - 4 * square_distance(s, s2);
+ s2 = pop_1st_bit(&b);
+ r2 = square_rank(s2);
+ v = StormLeverBonus[f] - 4 * rank_distance(r, r2);
// If enemy pawn has no pawn beside itself is particularly vulnerable.
// Big bonus, especially against a weakness on the rook file
}
pi->qsStormValue[Us] += bonus;
- // Member of a pawn chain (but not the backward one)? We could speed up
- // the test a little by introducing an array of masks indexed by color
- // and square for doing the test, but because everything is hashed,
- // it probably won't make any noticable difference.
- chain = ourPawns
- & neighboring_files_bb(f)
- & (rank_bb(r) | rank_bb(r - (Us == WHITE ? 1 : -1)));
+ // Our rank and previous one. Used for chain detection.
+ b = rank_bb(r) | rank_bb(r + (Us == WHITE ? -1 : 1));
+
+ // Passed, isolated, doubled or member of a pawn
+ // chain (but not the backward one) ?
+ passed = !(theirPawns & passed_pawn_mask(Us, s));
+ doubled = ourPawns & squares_behind(Us, s);
+ opposed = theirPawns & squares_in_front_of(Us, s);
+ isolated = !(ourPawns & neighboring_files_bb(f));
+ chain = ourPawns & neighboring_files_bb(f) & b;
// Test for backward pawn
//
// there are friendly pawns behind on neighboring files it cannot
// be backward either.
if ( (passed | isolated | chain)
- || (ourPawns & behind_bb(Us, r) & neighboring_files_bb(f))
+ || (ourPawns & outpost_mask(opposite_color(Us), s))
|| (pos.attacks_from<PAWN>(s, Us) & theirPawns))
backward = false;
else
// pawn on neighboring files. We now check whether the pawn is
// backward by looking in the forward direction on the neighboring
// files, and seeing whether we meet a friendly or an enemy pawn first.
-
Bitboard b = pos.attacks_from<PAWN>(s, Us);
+ b = pos.attacks_from<PAWN>(s, Us);
// Note that we are sure to find something because pawn is not passed
// nor isolated, so loop is potentially infinite, but it isn't.
if (passed && (ourPawns & squares_in_front_of(Us, s)))
passed = false;
- // Score this pawn
+ // Mark the pawn as passed. Pawn will be properly scored in evaluation
+ // because we need full attack info to evaluate passed pawns.
if (passed)
set_bit(&(pi->passedPawns), s);
+ // Score this pawn
if (isolated)
{
value -= IsolatedPawnPenalty[f];
/// only when king square changes, about 20% of total get_king_shelter() calls.
int PawnInfo::updateShelter(const Position& pos, Color c, Square ksq) {
- unsigned shelter = 0;
Bitboard pawns = pos.pieces(PAWN, c) & this_and_neighboring_files_bb(ksq);
+ unsigned shelter = 0;
unsigned r = ksq & (7 << 3);
+
for (int i = 1, k = (c ? -8 : 8); i < 4; i++)
{
r += k;
projects / stockfish / commitdiff