along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <algorithm>
#include <cassert>
#include "bitboard.h"
#define S(mg, eg) make_score(mg, eg)
// Doubled pawn penalty by opposed flag and file
- const Score DoubledPawnPenalty[2][FILE_NB] = {
+ const Score Doubled[2][FILE_NB] = {
{ S(13, 43), S(20, 48), S(23, 48), S(23, 48),
S(23, 48), S(23, 48), S(20, 48), S(13, 43) },
{ S(13, 43), S(20, 48), S(23, 48), S(23, 48),
S(23, 48), S(23, 48), S(20, 48), S(13, 43) }};
// Isolated pawn penalty by opposed flag and file
- const Score IsolatedPawnPenalty[2][FILE_NB] = {
+ const Score Isolated[2][FILE_NB] = {
{ S(37, 45), S(54, 52), S(60, 52), S(60, 52),
S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
{ S(25, 30), S(36, 35), S(40, 35), S(40, 35),
S(40, 35), S(40, 35), S(36, 35), S(25, 30) }};
// Backward pawn penalty by opposed flag and file
- const Score BackwardPawnPenalty[2][FILE_NB] = {
+ const Score Backward[2][FILE_NB] = {
{ S(30, 42), S(43, 46), S(49, 46), S(49, 46),
S(49, 46), S(49, 46), S(43, 46), S(30, 42) },
{ S(20, 28), S(29, 31), S(33, 31), S(33, 31),
S(33, 31), S(33, 31), S(29, 31), S(20, 28) }};
// Pawn chain membership bonus by file
- const Score ChainBonus[FILE_NB] = {
+ const Score ChainMember[FILE_NB] = {
S(11,-1), S(13,-1), S(13,-1), S(14,-1),
S(14,-1), S(13,-1), S(13,-1), S(11,-1)
};
// Candidate passed pawn bonus by rank
- const Score CandidateBonus[RANK_NB] = {
+ const Score CandidatePassed[RANK_NB] = {
S( 0, 0), S( 6, 13), S(6,13), S(14,29),
S(34,68), S(83,166), S(0, 0), S( 0, 0)
};
- const Score PawnStructureWeight = S(233, 201);
-
// Weakness of our pawn shelter in front of the king indexed by [king pawn][rank]
const Value ShelterWeakness[2][RANK_NB] =
{ { V(141), V(0), V(38), V(102), V(128), V(141), V(141) },
#undef V
template<Color Us>
- Score evaluate_pawns(const Position& pos, Bitboard ourPawns,
- Bitboard theirPawns, Pawns::Entry* e) {
+ Score evaluate(const Position& pos, Pawns::Entry* e) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Color Them = (Us == WHITE ? BLACK : WHITE);
+ const Square Up = (Us == WHITE ? DELTA_N : DELTA_S);
+ const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
+ const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
Bitboard b;
Square s;
Rank r;
bool passed, isolated, doubled, opposed, chain, backward, candidate;
Score value = SCORE_ZERO;
- const Square* pl = pos.piece_list(Us, PAWN);
+ const Square* pl = pos.list<PAWN>(Us);
+
+ Bitboard ourPawns = pos.pieces(Us, PAWN);
+ Bitboard theirPawns = pos.pieces(Them, PAWN);
+
+ e->passedPawns[Us] = 0;
+ e->kingSquares[Us] = SQ_NONE;
+ e->semiopenFiles[Us] = 0xFF;
+ e->pawnAttacks[Us] = shift_bb<Right>(ourPawns) | shift_bb<Left>(ourPawns);
+ e->pawnsOnSquares[Us][BLACK] = popcount<Max15>(ourPawns & BlackSquares);
+ e->pawnsOnSquares[Us][WHITE] = pos.count<PAWN>(Us) - e->pawnsOnSquares[Us][BLACK];
// Loop through all pawns of the current color and score each pawn
while ((s = *pl++) != SQ_NONE)
f = file_of(s);
r = rank_of(s);
- // This file cannot be half open
- e->halfOpenFiles[Us] &= ~(1 << f);
+ // This file cannot be semi-open
+ e->semiopenFiles[Us] &= ~(1 << f);
// Our rank plus previous one. Used for chain detection
b = rank_bb(r) | rank_bb(Us == WHITE ? r - Rank(1) : r + Rank(1));
// be backward. If there are friendly pawns behind on adjacent files
// or if can capture an enemy pawn it cannot be backward either.
if ( !(passed | isolated | chain)
- && !(ourPawns & attack_span_mask(Them, s))
+ && !(ourPawns & pawn_attack_span(Them, s))
&& !(pos.attacks_from<PAWN>(s, Us) & theirPawns))
{
// We now know that there are no friendly pawns beside or behind this
// Note that we are sure to find something because pawn is not passed
// nor isolated, so loop is potentially infinite, but it isn't.
while (!(b & (ourPawns | theirPawns)))
- Us == WHITE ? b <<= 8 : b >>= 8;
+ b = shift_bb<Up>(b);
// The friendly pawn needs to be at least two ranks closer than the
// enemy pawn in order to help the potentially backward pawn advance.
- backward = (b | (Us == WHITE ? b << 8 : b >> 8)) & theirPawns;
+ backward = (b | shift_bb<Up>(b)) & theirPawns;
}
- assert(opposed | passed | (attack_span_mask(Us, s) & theirPawns));
+ assert(opposed | passed | (pawn_attack_span(Us, s) & theirPawns));
// A not passed pawn is a candidate to become passed if it is free to
// advance and if the number of friendly pawns beside or behind this
// pawn on adjacent files is higher or equal than the number of
// enemy pawns in the forward direction on the adjacent files.
candidate = !(opposed | passed | backward | isolated)
- && (b = attack_span_mask(Them, s + pawn_push(Us)) & ourPawns) != 0
- && popcount<Max15>(b) >= popcount<Max15>(attack_span_mask(Us, s) & theirPawns);
+ && (b = pawn_attack_span(Them, s + pawn_push(Us)) & ourPawns) != 0
+ && popcount<Max15>(b) >= popcount<Max15>(pawn_attack_span(Us, s) & theirPawns);
// Passed pawns will be properly scored in evaluation because we need
// full attack info to evaluate passed pawns. Only the frontmost passed
// Score this pawn
if (isolated)
- value -= IsolatedPawnPenalty[opposed][f];
+ value -= Isolated[opposed][f];
if (doubled)
- value -= DoubledPawnPenalty[opposed][f];
+ value -= Doubled[opposed][f];
if (backward)
- value -= BackwardPawnPenalty[opposed][f];
+ value -= Backward[opposed][f];
if (chain)
- value += ChainBonus[f];
+ value += ChainMember[f];
if (candidate)
- value += CandidateBonus[relative_rank(Us, s)];
+ value += CandidatePassed[relative_rank(Us, s)];
}
return value;
}
-}
+
+} // namespace
namespace Pawns {
Key key = pos.pawn_key();
Entry* e = entries[key];
- // If e->key matches the position's pawn hash key, it means that we
- // have analysed this pawn structure before, and we can simply return
- // the information we found the last time instead of recomputing it.
if (e->key == key)
return e;
e->key = key;
- e->passedPawns[WHITE] = e->passedPawns[BLACK] = 0;
- e->kingSquares[WHITE] = e->kingSquares[BLACK] = SQ_NONE;
- e->halfOpenFiles[WHITE] = e->halfOpenFiles[BLACK] = 0xFF;
-
- Bitboard wPawns = pos.pieces(WHITE, PAWN);
- Bitboard bPawns = pos.pieces(BLACK, PAWN);
- e->pawnAttacks[WHITE] = ((wPawns & ~FileHBB) << 9) | ((wPawns & ~FileABB) << 7);
- e->pawnAttacks[BLACK] = ((bPawns & ~FileHBB) >> 7) | ((bPawns & ~FileABB) >> 9);
-
- e->value = evaluate_pawns<WHITE>(pos, wPawns, bPawns, e)
- - evaluate_pawns<BLACK>(pos, bPawns, wPawns, e);
-
- e->value = apply_weight(e->value, PawnStructureWeight);
-
+ e->value = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
return e;
}
const Color Them = (Us == WHITE ? BLACK : WHITE);
Value safety = MaxSafetyBonus;
- Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, ksq) | rank_bb(ksq));
+ Bitboard b = pos.pieces(PAWN) & (in_front_bb(Us, rank_of(ksq)) | rank_bb(ksq));
Bitboard ourPawns = b & pos.pieces(Us) & ~rank_bb(ksq);
Bitboard theirPawns = b & pos.pieces(Them);
Rank rkUs, rkThem;
File kf = file_of(ksq);
- kf = (kf == FILE_A) ? kf++ : (kf == FILE_H) ? kf-- : kf;
+ kf = (kf == FILE_A) ? FILE_B : (kf == FILE_H) ? FILE_G : kf;
for (int f = kf - 1; f <= kf + 1; f++)
{
projects / stockfish / blobdiff