#include <cassert>
#include "bitboard.h"
-#include "bitcount.h"
#include "pawns.h"
#include "position.h"
#include "thread.h"
#define V Value
#define S(mg, eg) make_score(mg, eg)
- // Isolated pawn penalty by opposed flag and file
- 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) } };
+ // Isolated pawn penalty by opposed flag
+ const Score Isolated[2] = { S(45, 40), S(30, 27) };
// Backward pawn penalty by opposed flag
- const Score Backward[2] = { S(67, 42), S(49, 24) };
-
+ const Score Backward[2] = { S(56, 33), S(41, 19) };
+
// Unsupported pawn penalty for pawns which are neither isolated or backward,
// by number of pawns it supports [less than 2 / exactly 2].
- const Score Unsupported[2] = { S(20, 10), S(25, 15) };
+ const Score Unsupported[2] = { S(17, 8), S(21, 12) };
// Connected pawn bonus by opposed, phalanx, twice supported and rank
Score Connected[2][2][2][RANK_NB];
-
- // Doubled pawn penalty by file
- const Score Doubled[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) };
+
+ // Doubled pawn penalty
+ const Score Doubled = S(18,38);
// Lever bonus by rank
const Score Lever[RANK_NB] = {
S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
- S(20, 20), S(40, 40), S(0, 0), S(0, 0) };
+ S(17, 16), S(33, 32), S(0, 0), S(0, 0) };
// Weakness of our pawn shelter in front of the king by [distance from edge][rank]
const Value ShelterWeakness[][RANK_NB] = {
const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
const Square Left = (Us == WHITE ? DELTA_NW : DELTA_SE);
- Bitboard b, neighbours, doubled, supported, phalanx;
+ Bitboard b, neighbours, stoppers, doubled, supported, phalanx;
Square s;
- bool passed, isolated, opposed, backward, lever, connected;
+ bool opposed, lever, connected, backward;
Score score = SCORE_ZERO;
const Square* pl = pos.squares<PAWN>(Us);
const Bitboard* pawnAttacksBB = StepAttacksBB[make_piece(Us, PAWN)];
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 & DarkSquares);
+ e->pawnsOnSquares[Us][BLACK] = popcount(ourPawns & DarkSquares);
e->pawnsOnSquares[Us][WHITE] = pos.count<PAWN>(Us) - e->pawnsOnSquares[Us][BLACK];
// Loop through all pawns of the current color and score each pawn
e->pawnAttacksSpan[Us] |= pawn_attack_span(Us, s);
// Flag the pawn
- neighbours = ourPawns & adjacent_files_bb(f);
- doubled = ourPawns & forward_bb(Us, s);
- opposed = theirPawns & forward_bb(Us, s);
- passed = !(theirPawns & passed_pawn_mask(Us, s));
- lever = theirPawns & pawnAttacksBB[s];
- phalanx = neighbours & rank_bb(s);
- supported = neighbours & rank_bb(s - Up);
- connected = supported | phalanx;
- isolated = !neighbours;
-
- // Test for backward pawn.
- // If the pawn is passed, isolated, lever or connected it cannot be
- // backward. If there are friendly pawns behind on adjacent files
- // or if it is sufficiently advanced, it cannot be backward either.
- if ( (passed | isolated | lever | connected)
- || (ourPawns & pawn_attack_span(Them, s))
- || (relative_rank(Us, s) >= RANK_5))
+ opposed = theirPawns & forward_bb(Us, s);
+ stoppers = theirPawns & passed_pawn_mask(Us, s);
+ lever = theirPawns & pawnAttacksBB[s];
+ doubled = ourPawns & (s + Up);
+ neighbours = ourPawns & adjacent_files_bb(f);
+ phalanx = neighbours & rank_bb(s);
+ supported = neighbours & rank_bb(s - Up);
+ connected = supported | phalanx;
+
+ // A pawn is backward when it is behind all pawns of the same color on the
+ // adjacent files and cannot be safely advanced.
+ if (!neighbours || lever || relative_rank(Us, s) >= RANK_5)
backward = false;
else
{
- // We now know there are no friendly pawns beside or behind this
- // pawn on adjacent files. We now check whether the pawn is
- // backward by looking in the forward direction on the adjacent
- // files, and picking the closest pawn there.
- b = pawn_attack_span(Us, s) & (ourPawns | theirPawns);
- b = pawn_attack_span(Us, s) & rank_bb(backmost_sq(Us, b));
-
- // If we have an enemy pawn in the same or next rank, the pawn is
- // backward because it cannot advance without being captured.
- backward = (b | shift_bb<Up>(b)) & theirPawns;
- }
+ // Find the backmost rank with neighbours or stoppers
+ b = rank_bb(backmost_sq(Us, neighbours | stoppers));
- assert(opposed | passed | (pawn_attack_span(Us, s) & theirPawns));
+ // The pawn is backward when it cannot safely progress to that rank:
+ // either there is a stopper in the way on this rank, or there is a
+ // stopper on adjacent file which controls the way to that rank.
+ backward = (b | shift_bb<Up>(b & adjacent_files_bb(f))) & stoppers;
+
+ assert(!backward || !(pawn_attack_span(Them, s + Up) & neighbours));
+ }
// Passed pawns will be properly scored in evaluation because we need
- // full attack info to evaluate them. Only the frontmost passed
- // pawn on each file is considered a true passed pawn.
- if (passed && !doubled)
+ // full attack info to evaluate them.
+ if (!stoppers && !(ourPawns & forward_bb(Us, s)))
e->passedPawns[Us] |= s;
// Score this pawn
- if (isolated)
- score -= Isolated[opposed][f];
+ if (!neighbours)
+ score -= Isolated[opposed];
else if (backward)
score -= Backward[opposed];
else if (!supported)
- score -= Unsupported[more_than_one(neighbours & rank_bb(s + Up))];
+ score -= Unsupported[more_than_one(neighbours & pawnAttacksBB[s])];
if (connected)
score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)];
if (doubled)
- score -= Doubled[f] / distance<Rank>(s, frontmost_sq(Us, doubled));
+ score -= Doubled;
if (lever)
score += Lever[relative_rank(Us, s)];
}
- b = e->semiopenFiles[Us] ^ 0xFF;
- e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
-
return score;
}
void init()
{
- static const int Seed[RANK_NB] = { 0, 6, 15, 10, 57, 75, 135, 258 };
+ static const int Seed[RANK_NB] = { 0, 8, 19, 13, 71, 94, 169, 324 };
for (int opposed = 0; opposed <= 1; ++opposed)
for (int phalanx = 0; phalanx <= 1; ++phalanx)
{
int v = (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed;
v += (apex ? v / 2 : 0);
- Connected[opposed][phalanx][apex][r] = make_score(3 * v / 2, v);
+ Connected[opposed][phalanx][apex][r] = make_score(v, v * 5 / 8);
}
}
e->key = key;
e->score = evaluate<WHITE>(pos, e) - evaluate<BLACK>(pos, e);
- e->asymmetry = popcount<Max15>(e->semiopenFiles[WHITE] ^ e->semiopenFiles[BLACK]);
+ e->asymmetry = popcount(e->semiopenFiles[WHITE] ^ e->semiopenFiles[BLACK]);
return e;
}
if (pawns)
while (!(DistanceRingBB[ksq][minKingPawnDistance++] & pawns)) {}
- if (relative_rank(Us, ksq) > RANK_4)
- return make_score(0, -16 * minKingPawnDistance);
-
Value bonus = shelter_storm<Us>(pos, ksq);
// If we can castle use the bonus after the castling if it is bigger
projects / stockfish / blobdiff