////
#include <cassert>
+#include <cstring>
#include "bitcount.h"
#include "pawns.h"
/// Constants and variables
- // Doubled pawn penalty by file, middle game.
+ // Doubled pawn penalty by file, middle game
const Value DoubledPawnMidgamePenalty[8] = {
Value(13), Value(20), Value(23), Value(23),
Value(23), Value(23), Value(20), Value(13)
};
- // Doubled pawn penalty by file, endgame.
+ // Doubled pawn penalty by file, endgame
const Value DoubledPawnEndgamePenalty[8] = {
Value(43), Value(48), Value(48), Value(48),
Value(48), Value(48), Value(48), Value(43)
};
- // Isolated pawn penalty by file, middle game.
+ // Isolated pawn penalty by file, middle game
const Value IsolatedPawnMidgamePenalty[8] = {
Value(25), Value(36), Value(40), Value(40),
Value(40), Value(40), Value(36), Value(25)
};
- // Isolated pawn penalty by file, endgame.
+ // Isolated pawn penalty by file, endgame
const Value IsolatedPawnEndgamePenalty[8] = {
Value(30), Value(35), Value(35), Value(35),
Value(35), Value(35), Value(35), Value(30)
};
- // Backward pawn penalty by file, middle game.
+ // Backward pawn penalty by file, middle game
const Value BackwardPawnMidgamePenalty[8] = {
Value(20), Value(29), Value(33), Value(33),
Value(33), Value(33), Value(29), Value(20)
};
- // Backward pawn penalty by file, endgame.
+ // Backward pawn penalty by file, endgame
const Value BackwardPawnEndgamePenalty[8] = {
Value(28), Value(31), Value(31), Value(31),
Value(31), Value(31), Value(31), Value(28)
};
- // Pawn chain membership bonus by file, middle game.
+ // Pawn chain membership bonus by file, middle game
const Value ChainMidgameBonus[8] = {
Value(11), Value(13), Value(13), Value(14),
Value(14), Value(13), Value(13), Value(11)
};
- // Pawn chain membership bonus by file, endgame.
+ // Pawn chain membership bonus by file, endgame
const Value ChainEndgameBonus[8] = {
Value(-1), Value(-1), Value(-1), Value(-1),
Value(-1), Value(-1), Value(-1), Value(-1)
};
- // Candidate passed pawn bonus by rank, middle game.
+ // Candidate passed pawn bonus by rank, middle game
const Value CandidateMidgameBonus[8] = {
Value( 0), Value( 6), Value(6), Value(14),
Value(34), Value(83), Value(0), Value( 0)
};
- // Candidate passed pawn bonus by rank, endgame.
+ // Candidate passed pawn bonus by rank, endgame
const Value CandidateEndgameBonus[8] = {
Value( 0), Value( 13), Value(13), Value(29),
Value(68), Value(166), Value( 0), Value( 0)
};
- // Pawn storm tables for positions with opposite castling:
+ // Pawn storm tables for positions with opposite castling
const int QStormTable[64] = {
0, 0, 0, 0, 0, 0, 0, 0,
-22,-22,-22,-14,-6, 0, 0, 0,
size = numOfEntries;
entries = new PawnInfo[size];
- if (entries == NULL)
+ if (!entries)
{
std::cerr << "Failed to allocate " << (numOfEntries * sizeof(PawnInfo))
<< " bytes for pawn hash table." << std::endl;
}
+/// PawnInfo::clear() resets to zero the PawnInfo entry. Note that
+/// kingSquares[] is initialized to SQ_NONE instead.
+
+void PawnInfo::clear() {
+
+ memset(this, 0, sizeof(PawnInfo));
+ kingSquares[WHITE] = kingSquares[BLACK] = SQ_NONE;
+}
+
+
/// 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.
-PawnInfo *PawnInfoTable::get_pawn_info(const Position &pos) {
+PawnInfo* PawnInfoTable::get_pawn_info(const Position& pos) {
assert(pos.is_ok());
Key key = pos.get_pawn_key();
int index = int(key & (size - 1));
- PawnInfo *pi = entries + index;
+ PawnInfo* pi = entries + index;
// If pi->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
+ // have analysed this pawn structure before, and we can simply return
+ // the information we found the last time instead of recomputing it.
if (pi->key == key)
return pi;
Value mgValue[2] = {Value(0), Value(0)};
Value egValue[2] = {Value(0), Value(0)};
+ // Calculate pawn attacks
+ pi->pawnAttacks[WHITE] = ((pos.pieces(PAWN, WHITE) << 9) & ~FileABB) | ((pos.pieces(PAWN, WHITE) << 7) & ~FileHBB);
+ pi->pawnAttacks[BLACK] = ((pos.pieces(PAWN, BLACK) >> 7) & ~FileABB) | ((pos.pieces(PAWN, BLACK) >> 9) & ~FileHBB);
+
// Loop through the pawns for both colors
for (Color us = WHITE; us <= BLACK; us++)
{
Color them = opposite_color(us);
- Bitboard ourPawns = pos.pawns(us);
- Bitboard theirPawns = pos.pawns(them);
+ Bitboard ourPawns = pos.pieces(PAWN, us);
+ Bitboard theirPawns = pos.pieces(PAWN, them);
Bitboard pawns = ourPawns;
- int bonus;
// Initialize pawn storm scores by giving bonuses for open files
for (File f = FILE_A; f <= FILE_H; f++)
- if (Position::file_is_half_open(ourPawns, f))
+ if (!(pawns & file_bb(f)))
{
pi->ksStormValue[us] += KStormOpenFileBonus[f];
pi->qsStormValue[us] += QStormOpenFileBonus[f];
+ pi->halfOpenFiles[us] |= (1 << f);
}
// Loop through all pawns of the current color and score each pawn
while (pawns)
{
- bool passed, doubled, isolated, backward, chain, candidate;
Square s = pop_1st_bit(&pawns);
File f = square_file(s);
Rank r = square_rank(s);
assert(pos.piece_on(s) == piece_of_color_and_type(us, PAWN));
- // The file containing the pawn is not half open
- pi->halfOpenFiles[us] &= ~(1 << f);
-
// Passed, isolated or doubled pawn?
- passed = Position::pawn_is_passed(theirPawns, us, s);
- isolated = Position::pawn_is_isolated(ourPawns, s);
- doubled = Position::pawn_is_doubled(ourPawns, us, s);
+ bool passed = Position::pawn_is_passed(theirPawns, us, s);
+ bool isolated = Position::pawn_is_isolated(ourPawns, s);
+ bool doubled = Position::pawn_is_doubled(ourPawns, us, s);
// We calculate kingside and queenside pawn storm
// scores for both colors. These are used when evaluating
// enemy pawn on an adjacent file gets an additional bonus.
// Kingside pawn storms
- bonus = KStormTable[relative_square(us, s)];
+ int bonus = KStormTable[relative_square(us, s)];
if (f >= FILE_F)
{
Bitboard b = outpost_mask(us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
// 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)));
+ bool chain = ourPawns
+ & neighboring_files_bb(f)
+ & (rank_bb(r) | rank_bb(r - (us == WHITE ? 1 : -1)));
// Test for backward pawn
//
// it cannot be backward. If can capture an enemy pawn or if
// there are friendly pawns behind on neighboring files it cannot
// be backward either.
- if ( passed
- || isolated
- || chain
- || (pos.pawn_attacks(us, s) & theirPawns)
- || (ourPawns & behind_bb(us, r) & neighboring_files_bb(f)))
+
+ bool backward;
+ if ( (passed | isolated | chain)
+ || (ourPawns & behind_bb(us, r) & neighboring_files_bb(f))
+ || (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;
+ Bitboard b = pos.attacks_from<PAWN>(s, us);
if (us == WHITE)
{
- for (b = pos.pawn_attacks(us, s); !(b & (ourPawns | theirPawns)); b <<= 8);
+ for ( ; !(b & (ourPawns | theirPawns)); b <<= 8);
backward = (b | (b << 8)) & theirPawns;
}
else
{
- for (b = pos.pawn_attacks(us, s); !(b & (ourPawns | theirPawns)); b >>= 8);
+ for ( ; !(b & (ourPawns | theirPawns)); b >>= 8);
backward = (b | (b >> 8)) & theirPawns;
}
}
// Test for candidate passed pawn
+ bool candidate;
candidate = !passed
- && Position::file_is_half_open(theirPawns, f)
- && ( count_1s_max_15(neighboring_files_bb(f) & (behind_bb(us, r) | rank_bb(r)) & ourPawns)
- - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(us, r) & theirPawns)
- >= 0);
+ && !(theirPawns & file_bb(f))
+ && ( count_1s_max_15(neighboring_files_bb(f) & (behind_bb(us, r) | rank_bb(r)) & ourPawns)
+ - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(us, r) & theirPawns)
+ >= 0);
// In order to prevent doubled passed pawns from receiving a too big
// bonus, only the frontmost passed pawn on each file is considered as
// a true passed pawn.
if (passed && (ourPawns & squares_in_front_of(us, s)))
- {
- // candidate = true;
passed = false;
- }
// Score this pawn
- Value mv = Value(0), ev = Value(0);
+ if (passed)
+ set_bit(&(pi->passedPawns), s);
+
if (isolated)
{
- mv -= IsolatedPawnMidgamePenalty[f];
- ev -= IsolatedPawnEndgamePenalty[f];
- if (Position::file_is_half_open(theirPawns, f))
+ mgValue[us] -= IsolatedPawnMidgamePenalty[f];
+ egValue[us] -= IsolatedPawnEndgamePenalty[f];
+ if (!(theirPawns & file_bb(f)))
{
- mv -= IsolatedPawnMidgamePenalty[f] / 2;
- ev -= IsolatedPawnEndgamePenalty[f] / 2;
+ mgValue[us] -= IsolatedPawnMidgamePenalty[f] / 2;
+ egValue[us] -= IsolatedPawnEndgamePenalty[f] / 2;
}
}
if (doubled)
{
- mv -= DoubledPawnMidgamePenalty[f];
- ev -= DoubledPawnEndgamePenalty[f];
+ mgValue[us] -= DoubledPawnMidgamePenalty[f];
+ egValue[us] -= DoubledPawnEndgamePenalty[f];
}
if (backward)
{
- mv -= BackwardPawnMidgamePenalty[f];
- ev -= BackwardPawnEndgamePenalty[f];
- if (Position::file_is_half_open(theirPawns, f))
+ mgValue[us] -= BackwardPawnMidgamePenalty[f];
+ egValue[us] -= BackwardPawnEndgamePenalty[f];
+ if (!(theirPawns & file_bb(f)))
{
- mv -= BackwardPawnMidgamePenalty[f] / 2;
- ev -= BackwardPawnEndgamePenalty[f] / 2;
+ mgValue[us] -= BackwardPawnMidgamePenalty[f] / 2;
+ egValue[us] -= BackwardPawnEndgamePenalty[f] / 2;
}
}
if (chain)
{
- mv += ChainMidgameBonus[f];
- ev += ChainEndgameBonus[f];
+ mgValue[us] += ChainMidgameBonus[f];
+ egValue[us] += ChainEndgameBonus[f];
}
if (candidate)
{
- mv += CandidateMidgameBonus[relative_rank(us, s)];
- ev += CandidateEndgameBonus[relative_rank(us, s)];
+ mgValue[us] += CandidateMidgameBonus[relative_rank(us, s)];
+ egValue[us] += CandidateEndgameBonus[relative_rank(us, s)];
}
-
- mgValue[us] += mv;
- egValue[us] += ev;
-
- // If the pawn is passed, set the square of the pawn in the passedPawns
- // bitboard
- if (passed)
- set_bit(&(pi->passedPawns), s);
} // while(pawns)
} // for(colors)
pi->egValue = int16_t(egValue[WHITE] - egValue[BLACK]);
return pi;
}
+
+
+/// PawnInfo::updateShelter calculates and caches king shelter. It is called
+/// 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 r = ksq & (7 << 3);
+ for (int i = 1, k = (c ? -8 : 8); i < 4; i++)
+ {
+ r += k;
+ shelter += BitCount8Bit[(pawns >> r) & 0xFF] * (128 >> i);
+ }
+ kingSquares[c] = ksq;
+ kingShelters[c] = shelter;
+ return shelter;
+}
projects / stockfish / blobdiff