X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=f77972e352c0d9395054750bca0ebe93aef3e73c;hp=7e2331277d59ed8b21d40063414c3cf79ef8f50f;hb=d706ae62d73d90c0f80cdccd58384a347295d549;hpb=436c3037310ad997f85a5da0685b6bc91699163b
diff --git a/src/material.cpp b/src/material.cpp
index 7e233127..f77972e3 100644
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -1,7 +1,6 @@
/*
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) 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
@@ -17,7 +16,6 @@
along with this program. If not, see .
*/
-#include // For std::min
#include
#include // For std::memset
@@ -27,34 +25,34 @@
using namespace std;
namespace {
+ #define S(mg, eg) make_score(mg, eg)
// Polynomial material imbalance parameters
- // pair pawn knight bishop rook queen
- const int Linear[6] = { 1756, -164, -1067, -160, 234, -137 };
-
- const int QuadraticOurs[][PIECE_TYPE_NB] = {
+ constexpr Score QuadraticOurs[][PIECE_TYPE_NB] = {
// OUR PIECES
// pair pawn knight bishop rook queen
- { 0 }, // Bishop pair
- { 39, 2 }, // Pawn
- { 35, 271, -4 }, // Knight OUR PIECES
- { 0, 105, 4, 0 }, // Bishop
- { -27, -2, 46, 100, -141 }, // Rook
- {-177, 25, 129, 142, -137, 0 } // 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
};
- const int QuadraticTheirs[][PIECE_TYPE_NB] = {
+ constexpr Score QuadraticTheirs[][PIECE_TYPE_NB] = {
// THEIR PIECES
// pair pawn knight bishop rook queen
- { 0 }, // Bishop pair
- { 37, 0 }, // Pawn
- { 10, 62, 0 }, // Knight OUR PIECES
- { 57, 64, 39, 0 }, // Bishop
- { 50, 40, 23, -22, 0 }, // Rook
- { 98, 105, -39, 141, 274, 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 EvaluateKXK[] = { Endgame(WHITE), Endgame(BLACK) };
@@ -70,38 +68,38 @@ namespace {
&& pos.non_pawn_material(us) >= RookValueMg;
}
- bool is_KBPsKs(const Position& pos, Color us) {
+ bool is_KBPsK(const Position& pos, Color us) {
return pos.non_pawn_material(us) == BishopValueMg
- && pos.count(us) == 1
&& pos.count(us) >= 1;
}
bool is_KQKRPs(const Position& pos, Color us) {
return !pos.count(us)
&& pos.non_pawn_material(us) == QueenValueMg
- && pos.count(us) == 1
&& pos.count(~us) == 1
&& pos.count(~us) >= 1;
}
+
/// imbalance() calculates the imbalance by comparing the piece count of each
/// piece type for both colors.
+
template
- int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
+ Score imbalance(const int pieceCount[][PIECE_TYPE_NB]) {
- const 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
+ // Second-degree polynomial material imbalance, by Tord Romstad
for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; ++pt1)
{
if (!pieceCount[Us][pt1])
continue;
- int v = Linear[pt1];
+ 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];
@@ -115,6 +113,7 @@ namespace {
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
@@ -131,15 +130,21 @@ Entry* probe(const Position& pos) {
std::memset(e, 0, sizeof(Entry));
e->key = key;
e->factor[WHITE] = e->factor[BLACK] = (uint8_t)SCALE_FACTOR_NORMAL;
- e->gamePhase = pos.game_phase();
+
+ Value npm_w = pos.non_pawn_material(WHITE);
+ Value npm_b = pos.non_pawn_material(BLACK);
+ 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(key)) != nullptr)
+ if ((e->evaluationFunction = Endgames::probe(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];
@@ -148,29 +153,26 @@ Entry* probe(const Position& pos) {
// OK, we didn't find any special evaluation function for the current material
// configuration. Is there a suitable specialized scaling function?
- EndgameBase* sf;
+ const auto* sf = Endgames::probe(key);
- if ((sf = pos.this_thread()->endgames.probe(key)) != nullptr)
+ if (sf)
{
- e->scalingFunction[sf->strong_side()] = sf; // Only strong color assigned
+ 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_KBPsKs(pos, c))
+ if (is_KBPsK(pos, c))
e->scalingFunction[c] = &ScaleKBPsK[c];
else if (is_KQKRPs(pos, c))
e->scalingFunction[c] = &ScaleKQKRPs[c];
}
- Value npm_w = pos.non_pawn_material(WHITE);
- Value npm_b = pos.non_pawn_material(BLACK);
-
if (npm_w + npm_b == VALUE_ZERO && pos.pieces(PAWN)) // Only pawns on the board
{
if (!pos.count(BLACK))
@@ -205,22 +207,16 @@ Entry* probe(const Position& pos) {
e->factor[BLACK] = uint8_t(npm_b < RookValueMg ? SCALE_FACTOR_DRAW :
npm_w <= BishopValueMg ? 4 : 14);
- if (pos.count(WHITE) == 1 && npm_w - npm_b <= BishopValueMg)
- e->factor[WHITE] = (uint8_t) SCALE_FACTOR_ONEPAWN;
-
- if (pos.count(BLACK) == 1 && npm_b - npm_w <= BishopValueMg)
- e->factor[BLACK] = (uint8_t) SCALE_FACTOR_ONEPAWN;
-
// Evaluate the material imbalance. We use PIECE_TYPE_NONE as a place holder
// for the bishop pair "extended piece", which allows us to be more flexible
// in defining bishop pair bonuses.
- const int PieceCount[COLOR_NB][PIECE_TYPE_NB] = {
+ const int pieceCount[COLOR_NB][PIECE_TYPE_NB] = {
{ pos.count(WHITE) > 1, pos.count(WHITE), pos.count(WHITE),
pos.count(WHITE) , pos.count(WHITE), pos.count(WHITE) },
{ pos.count(BLACK) > 1, pos.count(BLACK), pos.count(BLACK),
pos.count(BLACK) , pos.count(BLACK), pos.count(BLACK) } };
- e->value = int16_t((imbalance(PieceCount) - imbalance(PieceCount)) / 16);
+ e->score = (imbalance(pieceCount) - imbalance(pieceCount)) / 16;
return e;
}