/*
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
#include <cassert>
#include <cstring>
+#include "bitcount.h"
#include "pawns.h"
#include "position.h"
/// Constants and variables
- // Doubled pawn penalty by file, middle game.
+ // 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.
+ // 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.
+ // 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.
+ // 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.
+ // 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.
+ // 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.
+ // 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.
+ // 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)
};
- // 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,-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 };
- const int QStormOpenFileBonus[8] = { 0, 0, 0, 0, 0, 30, 45, 30 };
+ 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 };
// Pawn storm lever bonuses by file
- const int StormLeverBonus[8] = { 20, 20, 10, 0, 0, 10, 20, 20 };
+ const int StormLeverBonus[8] = { -8, -8, -13, 0, 0, -13, -8, -8 };
}
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;
- exit(EXIT_FAILURE);
+ Application::exit_with_failure();
}
- clear();
}
}
-/// PawnInfoTable::clear() clears the pawn hash table by setting all
-/// entries to 0.
+/// PawnInfo::clear() resets to zero the PawnInfo entry. Note that
+/// kingSquares[] is initialized to SQ_NONE instead.
-void PawnInfoTable::clear() {
- memset(entries, 0, size * sizeof(PawnInfo));
+void PawnInfo::clear() {
+
+ memset(this, 0, sizeof(PawnInfo));
+ kingSquares[WHITE] = kingSquares[BLACK] = SQ_NONE;
}
/// 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 (pos.file_is_half_open(us, 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 = pos.pawn_is_passed(us, s);
- isolated = pos.pawn_is_isolated(us, s);
- doubled = pos.pawn_is_doubled(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.
+ bool backward;
if ( passed
|| isolated
|| chain
- || (pos.pawn_attacks(us, s) & theirPawns)
+ || (pos.attacks_from<PAWN>(s, us) & theirPawns)
|| (ourPawns & behind_bb(us, r) & neighboring_files_bb(f)))
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
- && pos.file_is_half_open(them, 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 (pos.file_is_half_open(them, 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 (pos.file_is_half_open(them, 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;
+}