/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
- Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-#include <algorithm> // For std::min
#include <cassert>
#include <cstring> // For std::memset
using namespace std;
namespace {
+ #define S(mg, eg) make_score(mg, eg)
// Polynomial material imbalance parameters
- constexpr int QuadraticOurs[][PIECE_TYPE_NB] = {
+ constexpr Score QuadraticOurs[][PIECE_TYPE_NB] = {
// OUR PIECES
// pair pawn knight bishop rook queen
- {1667 }, // Bishop pair
- { 40, 0 }, // Pawn
- { 32, 255, -3 }, // Knight OUR PIECES
- { 0, 104, 4, 0 }, // Bishop
- { -26, -2, 47, 105, -149 }, // Rook
- {-189, 24, 117, 133, -134, -10 } // Queen
+ {S(1419, 1455) }, // Bishop pair
+ {S( 101, 28), S( 37, 39) }, // Pawn
+ {S( 57, 64), S(249, 187), S(-49, -62) }, // Knight OUR PIECES
+ {S( 0, 0), S(118, 137), S( 10, 27), S( 0, 0) }, // Bishop
+ {S( -63, -68), S( -5, 3), S(100, 81), S(132, 118), S(-246, -244) }, // Rook
+ {S(-210, -211), S( 37, 14), S(147, 141), S(161, 105), S(-158, -174), S(-9,-31) } // Queen
};
- constexpr int QuadraticTheirs[][PIECE_TYPE_NB] = {
+ constexpr Score QuadraticTheirs[][PIECE_TYPE_NB] = {
// THEIR PIECES
// pair pawn knight bishop rook queen
- { 0 }, // Bishop pair
- { 36, 0 }, // Pawn
- { 9, 63, 0 }, // Knight OUR PIECES
- { 59, 65, 42, 0 }, // Bishop
- { 46, 39, 24, -24, 0 }, // Rook
- { 97, 100, -42, 137, 268, 0 } // Queen
+ { }, // Bishop pair
+ {S( 33, 30) }, // Pawn
+ {S( 46, 18), S(106, 84) }, // Knight OUR PIECES
+ {S( 75, 35), S( 59, 44), S( 60, 15) }, // Bishop
+ {S( 26, 35), S( 6, 22), S( 38, 39), S(-12, -2) }, // Rook
+ {S( 97, 93), S(100, 163), S(-58, -91), S(112, 192), S(276, 225) } // Queen
};
+ #undef S
+
// Endgame evaluation and scaling functions are accessed directly and not through
// the function maps because they correspond to more than one material hash key.
Endgame<KXK> EvaluateKXK[] = { Endgame<KXK>(WHITE), Endgame<KXK>(BLACK) };
bool is_KBPsK(const Position& pos, Color us) {
return pos.non_pawn_material(us) == BishopValueMg
- && pos.count<BISHOP>(us) == 1
&& pos.count<PAWN >(us) >= 1;
}
bool is_KQKRPs(const Position& pos, Color us) {
return !pos.count<PAWN>(us)
&& pos.non_pawn_material(us) == QueenValueMg
- && pos.count<QUEEN>(us) == 1
&& pos.count<ROOK>(~us) == 1
&& pos.count<PAWN>(~us) >= 1;
}
+
/// imbalance() calculates the imbalance by comparing the piece count of each
/// piece type for both colors.
+
template<Color Us>
- int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
+ Score imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
- constexpr Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
- int bonus = 0;
+ Score bonus = SCORE_ZERO;
// Second-degree polynomial material imbalance, by Tord Romstad
for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
if (!pieceCount[Us][pt1])
continue;
- int v = 0;
+ int v = QuadraticOurs[pt1][pt1] * pieceCount[Us][pt1];
- for (int pt2 = NO_PIECE_TYPE; pt2 <= pt1; ++pt2)
+ for (int pt2 = NO_PIECE_TYPE; pt2 < pt1; ++pt2)
v += QuadraticOurs[pt1][pt2] * pieceCount[Us][pt2]
+ QuadraticTheirs[pt1][pt2] * pieceCount[Them][pt2];
namespace Material {
+
/// Material::probe() looks up the current position's material configuration in
/// the material hash table. It returns a pointer to the Entry if the position
/// is found. Otherwise a new Entry is computed and stored there, so we don't
Value npm_w = pos.non_pawn_material(WHITE);
Value npm_b = pos.non_pawn_material(BLACK);
- Value npm = std::max(EndgameLimit, std::min(npm_w + npm_b, MidgameLimit));
+ Value npm = std::clamp(npm_w + npm_b, EndgameLimit, MidgameLimit);
// Map total non-pawn material into [PHASE_ENDGAME, PHASE_MIDGAME]
e->gamePhase = Phase(((npm - EndgameLimit) * PHASE_MIDGAME) / (MidgameLimit - EndgameLimit));
// Let's look if we have a specialized evaluation function for this particular
// material configuration. Firstly we look for a fixed configuration one, then
// for a generic one if the previous search failed.
- if ((e->evaluationFunction = pos.this_thread()->endgames.probe<Value>(key)) != nullptr)
+ if ((e->evaluationFunction = Endgames::probe<Value>(key)) != nullptr)
return e;
- for (Color c = WHITE; c <= BLACK; ++c)
+ for (Color c : { WHITE, BLACK })
if (is_KXK(pos, c))
{
e->evaluationFunction = &EvaluateKXK[c];
// OK, we didn't find any special evaluation function for the current material
// configuration. Is there a suitable specialized scaling function?
- const EndgameBase<ScaleFactor>* sf;
+ const auto* sf = Endgames::probe<ScaleFactor>(key);
- if ((sf = pos.this_thread()->endgames.probe<ScaleFactor>(key)) != nullptr)
+ if (sf)
{
e->scalingFunction[sf->strongSide] = sf; // Only strong color assigned
return e;
// We didn't find any specialized scaling function, so fall back on generic
// ones that refer to more than one material distribution. Note that in this
// case we don't return after setting the function.
- for (Color c = WHITE; c <= BLACK; ++c)
+ for (Color c : { WHITE, BLACK })
{
if (is_KBPsK(pos, c))
e->scalingFunction[c] = &ScaleKBPsK[c];
{ pos.count<BISHOP>(BLACK) > 1, pos.count<PAWN>(BLACK), pos.count<KNIGHT>(BLACK),
pos.count<BISHOP>(BLACK) , pos.count<ROOK>(BLACK), pos.count<QUEEN >(BLACK) } };
- e->value = int16_t((imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16);
+ e->score = (imbalance<WHITE>(pieceCount) - imbalance<BLACK>(pieceCount)) / 16;
return e;
}
projects / stockfish / blobdiff