/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008 Marco Costalba
+ Copyright (C) 2008-2009 Marco Costalba
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-
+
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
////
#include <cassert>
-#include <cstring>
+#include "bitcount.h"
#include "pawns.h"
+#include "position.h"
////
// Doubled pawn penalty by file, middle game.
const Value DoubledPawnMidgamePenalty[8] = {
- Value(20), Value(30), Value(34), Value(34),
- Value(34), Value(34), Value(30), Value(20)
+ Value(13), Value(20), Value(23), Value(23),
+ Value(23), Value(23), Value(20), Value(13)
};
// Doubled pawn penalty by file, endgame.
const Value DoubledPawnEndgamePenalty[8] = {
- Value(35), Value(40), Value(40), Value(40),
- Value(40), Value(40), Value(40), Value(35)
+ Value(43), Value(48), Value(48), Value(48),
+ Value(48), Value(48), Value(48), Value(43)
};
// Isolated pawn penalty by file, middle game.
const Value IsolatedPawnMidgamePenalty[8] = {
- Value(20), Value(30), Value(34), Value(34),
- Value(34), Value(34), Value(30), Value(20)
+ Value(25), Value(36), Value(40), Value(40),
+ Value(40), Value(40), Value(36), Value(25)
};
// Isolated pawn penalty by file, endgame.
const Value IsolatedPawnEndgamePenalty[8] = {
- Value(35), Value(40), Value(40), Value(40),
- Value(40), Value(40), Value(40), Value(35)
+ Value(30), Value(35), Value(35), Value(35),
+ Value(35), Value(35), Value(35), Value(30)
};
// Backward pawn penalty by file, middle game.
const Value BackwardPawnMidgamePenalty[8] = {
- Value(16), Value(24), Value(27), Value(27),
- Value(27), Value(27), Value(24), Value(16)
+ Value(20), Value(29), Value(33), Value(33),
+ Value(33), Value(33), Value(29), Value(20)
};
// Backward pawn penalty by file, endgame.
const Value BackwardPawnEndgamePenalty[8] = {
- Value(28), Value(32), Value(32), Value(32),
- Value(32), Value(32), Value(32), Value(28)
+ 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(14), Value(16), Value(17), Value(18),
- Value(18), Value(17), Value(16), Value(14)
+ 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(16), Value(16), Value(16), Value(16),
- Value(16), Value(16), Value(16), Value(16)
+ Value(-1), Value(-1), Value(-1), Value(-1),
+ Value(-1), Value(-1), Value(-1), Value(-1)
};
// Candidate passed pawn bonus by rank, middle game.
const Value CandidateMidgameBonus[8] = {
- Value( 0), Value(12), Value(12), Value(20),
- Value(40), Value(90), Value( 0), Value( 0)
+ Value( 0), Value( 6), Value(6), Value(14),
+ Value(34), Value(83), Value(0), Value( 0)
};
// Candidate passed pawn bonus by rank, endgame.
const Value CandidateEndgameBonus[8] = {
- Value( 0), Value(24), Value(24), Value(40),
- Value(80), Value(180), Value(0), Value( 0)
+ Value( 0), Value( 13), Value(13), Value(29),
+ Value(68), Value(166), Value( 0), Value( 0)
};
- // Evaluate pawn storms?
- const bool EvaluatePawnStorms = true;
-
// Pawn storm tables for positions with opposite castling:
const int QStormTable[64] = {
0, 0, 0, 0, 0, 0, 0, 0,
- -22,-22,-22,-13,-4, 0, 0, 0,
- -4, -9, -9, -9,-4, 0, 0, 0,
- 9, 18, 22, 18, 9, 0, 0, 0,
- 22, 31, 31, 22, 0, 0, 0, 0,
- 31, 40, 40, 31, 0, 0, 0, 0,
- 31, 40, 40, 31, 0, 0, 0, 0,
+ -22,-22,-22,-14,-6, 0, 0, 0,
+ -6,-10,-10,-10,-6, 0, 0, 0,
+ 4, 12, 16, 12, 4, 0, 0, 0,
+ 16, 23, 23, 16, 0, 0, 0, 0,
+ 23, 31, 31, 23, 0, 0, 0, 0,
+ 23, 31, 31, 23, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
};
-
+
const int KStormTable[64] = {
- 0, 0, 0, 0, 0, 0, 0, 0,
- 0, 0, 0,-4,-13,-22,-27,-27,
- 0, 0, 0,-4, -9,-13,-18,-18,
- 0, 0, 0, 0, 9, 9, 9, 9,
- 0, 0, 0, 0, 9, 18, 27, 27,
- 0, 0, 0, 0, 9, 27, 40, 36,
- 0, 0, 0, 0, 0, 31, 40, 31,
- 0, 0, 0, 0, 0, 0, 0, 0
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0,-10,-19,-28,-33,-33,
+ 0, 0, 0,-10,-15,-19,-24,-24,
+ 0, 0, 0, 0, 1, 1, 1, 1,
+ 0, 0, 0, 0, 1, 10, 19, 19,
+ 0, 0, 0, 0, 1, 19, 31, 27,
+ 0, 0, 0, 0, 0, 22, 31, 22,
+ 0, 0, 0, 0, 0, 0, 0, 0
};
- // Pawn storm open file bonuses by file:
- const int KStormOpenFileBonus[8] = {
- 45, 45, 30, 0, 0, 0, 0, 0
- };
+ // Pawn storm open file bonuses by file
+ const int16_t KStormOpenFileBonus[8] = { 31, 31, 18, 0, 0, 0, 0, 0 };
+ const int16_t QStormOpenFileBonus[8] = { 0, 0, 0, 0, 0, 26, 42, 26 };
- const int QStormOpenFileBonus[8] = {
- 0, 0, 0, 0, 0, 30, 45, 30
- };
+ // Pawn storm lever bonuses by file
+ const int StormLeverBonus[8] = { -8, -8, -13, 0, 0, -13, -8, -8 };
}
{
std::cerr << "Failed to allocate " << (numOfEntries * sizeof(PawnInfo))
<< " bytes for pawn hash table." << std::endl;
- exit(EXIT_FAILURE);
+ Application::exit_with_failure();
}
- clear();
}
}
-/// PawnInfoTable::clear() clears the pawn hash table by setting all
-/// entries to 0.
-
-void PawnInfoTable::clear() {
- memset(entries, 0, size * sizeof(PawnInfo));
-}
-
-
/// PawnInfoTable::get_pawn_info() takes a position object as input, computes
-/// a PawnInfo object, and returns a pointer to it. The result is also
+/// 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.
int index = int(key & (size - 1));
PawnInfo *pi = entries + index;
- // If pi->key matches the position's pawn hash key, it means that we
+ // 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
if (pi->key == key)
Bitboard ourPawns = pos.pawns(us);
Bitboard theirPawns = pos.pawns(them);
Bitboard pawns = ourPawns;
+ int bonus;
// Initialize pawn storm scores by giving bonuses for open files
- if (EvaluatePawnStorms)
- for(File f = FILE_A; f <= FILE_H; f++)
- if(pos.file_is_half_open(us, f))
- {
- pi->ksStormValue[us] += KStormOpenFileBonus[f];
- pi->qsStormValue[us] += QStormOpenFileBonus[f];
- }
+ for (File f = FILE_A; f <= FILE_H; f++)
+ if (Position::file_is_half_open(ourPawns, f))
+ {
+ pi->ksStormValue[us] += KStormOpenFileBonus[f];
+ pi->qsStormValue[us] += QStormOpenFileBonus[f];
+ }
// Loop through all pawns of the current color and score each pawn
while (pawns)
File f = square_file(s);
Rank r = square_rank(s);
- assert(pos.piece_on(s) == pawn_of_color(us));
+ 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 = pos.pawn_is_passed(us, s);
- isolated = pos.pawn_is_isolated(us, s);
- doubled = pos.pawn_is_doubled(us, s);
+ passed = Position::pawn_is_passed(theirPawns, us, s);
+ isolated = Position::pawn_is_isolated(ourPawns, s);
+ doubled = Position::pawn_is_doubled(ourPawns, us, s);
- if (EvaluatePawnStorms)
+ // 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.
+
+ // Kingside pawn storms
+ bonus = KStormTable[relative_square(us, s)];
+ if (f >= FILE_F)
{
- // 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[]). This score is increased if
- // there are enemy pawns on adjacent files in front of the pawn.
- // This is because we want to be able to open files against the
- // enemy king, and to avoid blocking the pawn structure (e.g. white
- // pawns on h6, g5, black pawns on h7, g6, f7).
-
- // Kingside and queenside pawn storms
- bool outPost = (outpost_mask(us, s) & theirPawns);
- bool passed = (passed_pawn_mask(us, s) & theirPawns);
- int KBonus = KStormTable[relative_square(us, s)];
- int QBonus = QStormTable[relative_square(us, s)];
-
- switch (f) {
-
- case FILE_A:
- QBonus += passed * QBonus / 4;
- break;
-
- case FILE_B:
- QBonus += passed * (QBonus / 2 + QBonus / 4);
- break;
-
- case FILE_C:
- QBonus += passed * QBonus / 2;
- break;
-
- case FILE_F:
- KBonus += outPost * KBonus / 4;
- break;
-
- case FILE_G:
- KBonus += outPost * (KBonus / 2 + KBonus / 4);
- break;
-
- case FILE_H:
- KBonus += outPost * KBonus / 2;
- break;
-
- default:
- break;
+ Bitboard b = outpost_mask(us, s) & theirPawns & (FileFBB | FileGBB | FileHBB);
+ while (b)
+ {
+ Square s2 = pop_1st_bit(&b);
+ if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
+ {
+ // The enemy pawn has no pawn beside itself, which makes it
+ // particularly vulnerable. Big bonus, especially against a
+ // weakness on the rook file.
+ if (square_file(s2) == FILE_H)
+ bonus += 4*StormLeverBonus[f] - 8*square_distance(s, s2);
+ else
+ bonus += 2*StormLeverBonus[f] - 4*square_distance(s, s2);
+ } else
+ // There is at least one enemy pawn beside the enemy pawn we look
+ // at, which means that the pawn has somewhat better chances of
+ // defending itself by advancing. Smaller bonus.
+ bonus += StormLeverBonus[f] - 2*square_distance(s, s2);
}
- pi->ksStormValue[us] += KBonus;
- pi->qsStormValue[us] += QBonus;
}
+ pi->ksStormValue[us] += bonus;
+
+ // Queenside pawn storms
+ bonus = QStormTable[relative_square(us, s)];
+ if (f <= FILE_C)
+ {
+ Bitboard b = outpost_mask(us, s) & theirPawns & (FileABB | FileBBB | FileCBB);
+ while (b)
+ {
+ Square s2 = pop_1st_bit(&b);
+ if (!(theirPawns & neighboring_files_bb(s2) & rank_bb(s2)))
+ {
+ // The enemy pawn has no pawn beside itself, which makes it
+ // particularly vulnerable. Big bonus, especially against a
+ // weakness on the rook file.
+ if (square_file(s2) == FILE_A)
+ bonus += 4*StormLeverBonus[f] - 16*square_distance(s, s2);
+ else
+ bonus += 2*StormLeverBonus[f] - 8*square_distance(s, s2);
+ } else
+ // There is at least one enemy pawn beside the enemy pawn we look
+ // at, which means that the pawn has somewhat better chances of
+ // defending itself by advancing. Smaller bonus.
+ bonus += StormLeverBonus[f] - 4*square_distance(s, s2);
+ }
+ }
+ 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
|| isolated
|| chain
|| (pos.pawn_attacks(us, s) & theirPawns)
- || (ourPawns & in_front_bb(them, r) & neighboring_files_bb(f)))
+ || (ourPawns & behind_bb(us, r) & neighboring_files_bb(f)))
backward = false;
else
{
// Test for candidate passed pawn
candidate = !passed
- && pos.file_is_half_open(them, f)
- && ( count_1s_max_15(neighboring_files_bb(f) & (in_front_bb(them, r) | rank_bb(r)) & ourPawns)
- - count_1s_max_15(neighboring_files_bb(f) & in_front_bb(us, r) & theirPawns)
+ && 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);
// In order to prevent doubled passed pawns from receiving a too big
{
mv -= IsolatedPawnMidgamePenalty[f];
ev -= IsolatedPawnEndgamePenalty[f];
- if (pos.file_is_half_open(them, f))
+ if (Position::file_is_half_open(theirPawns, f))
{
mv -= IsolatedPawnMidgamePenalty[f] / 2;
ev -= IsolatedPawnEndgamePenalty[f] / 2;
{
mv -= BackwardPawnMidgamePenalty[f];
ev -= BackwardPawnEndgamePenalty[f];
- if (pos.file_is_half_open(them, f))
+ if (Position::file_is_half_open(theirPawns, f))
{
mv -= BackwardPawnMidgamePenalty[f] / 2;
ev -= BackwardPawnEndgamePenalty[f] / 2;
mgValue[us] += mv;
egValue[us] += ev;
-
+
// If the pawn is passed, set the square of the pawn in the passedPawns
// bitboard
if (passed)
projects / stockfish / blobdiff