X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmaterial.cpp;h=870a5e112cb8ed25536ec10a7165f8031c57702f;hp=8b659ecc2f612b1571d1fddf8e6cc478982e0329;hb=aa75388ec136a8cf83b09da2328c5fefd5a010bd;hpb=83e829c9dc900dcb00d673417062f4193481ff36
diff --git a/src/material.cpp b/src/material.cpp
index 8b659ecc..870a5e11 100644
--- a/src/material.cpp
+++ b/src/material.cpp
@@ -1,8 +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) 2015-2017 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
@@ -18,7 +16,6 @@
along with this program. If not, see .
*/
-#include // For std::min
#include
#include // For std::memset
@@ -31,26 +28,26 @@ namespace {
// Polynomial material imbalance parameters
- const int QuadraticOurs[][PIECE_TYPE_NB] = {
+ constexpr int QuadraticOurs[][PIECE_TYPE_NB] = {
// OUR PIECES
// pair pawn knight bishop rook queen
- {1667 }, // Bishop pair
- { 40, 0 }, // Pawn
- { 32, 255, -3 }, // Knight OUR PIECES
+ {1438 }, // Bishop pair
+ { 40, 38 }, // Pawn
+ { 32, 255, -62 }, // Knight OUR PIECES
{ 0, 104, 4, 0 }, // Bishop
- { -26, -2, 47, 105, -149 }, // Rook
- {-189, 24, 117, 133, -134, -10 } // Queen
+ { -26, -2, 47, 105, -208 }, // Rook
+ {-189, 24, 117, 133, -134, -6 } // Queen
};
- const int QuadraticTheirs[][PIECE_TYPE_NB] = {
+ constexpr int 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
+ { 36, }, // Pawn
+ { 9, 63, }, // Knight OUR PIECES
+ { 59, 65, 42, }, // Bishop
+ { 46, 39, 24, -24, }, // Rook
+ { 97, 100, -42, 137, 268, } // Queen
};
// Endgame evaluation and scaling functions are accessed directly and not through
@@ -68,26 +65,26 @@ 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]) {
- const Color Them = (Us == WHITE ? BLACK : WHITE);
+ constexpr Color Them = ~Us;
int bonus = 0;
@@ -97,9 +94,9 @@ namespace {
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];
@@ -113,6 +110,7 @@ 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
@@ -132,7 +130,7 @@ Entry* probe(const Position& pos) {
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));
@@ -140,10 +138,10 @@ Entry* probe(const Position& pos) {
// 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];
@@ -152,9 +150,9 @@ 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->strongSide] = sf; // Only strong color assigned
return e;
@@ -163,9 +161,9 @@ Entry* probe(const Position& pos) {
// 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))
@@ -206,22 +204,16 @@ 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->value = int16_t((imbalance(pieceCount) - imbalance(pieceCount)) / 16);
return e;
}