stellar

UCI Chess engine written in C++20
git clone git://git.dimitrijedobrota.com/stellar.git
Log | Files | Refs | README | LICENSE |
commit8bab42ac758595bc29cfc1ae86398a57e72cd963
parent362cc43b8bc8a4e5519238dc587ddd0b8eb30ee2
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateWed, 30 Aug 2023 18:07:52 +0200

General Search Improvement

Diffstat:
MCMakeLists.txt|+-
Msrc/engine/CMakeLists.txt|-------
Msrc/engine/engine.cpp|++++++++++++-----------------
Msrc/move/move.hpp|+-
Msrc/move/movelist.cpp|--------
Msrc/move/movelist.hpp|-

6 files changed, 14 insertions(+), 35 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt

@@ -3,7 +3,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

project(
Stellar
VERSION 0.0.25
VERSION 0.0.26
DESCRIPTION "Chess engine written in C"
HOMEPAGE_URL https://git.dimitrijedobrota.com/stellar.git
LANGUAGES C CXX

diff --git a/src/engine/CMakeLists.txt b/src/engine/CMakeLists.txt

@@ -11,13 +11,6 @@ target_link_libraries(engine

PRIVATE utils
)
stellar_target_precompile_headers(board
PRIVATE "board.hpp"
PRIVATE "move.hpp"
PRIVATE "movelist.hpp"
PRIVATE "piece.hpp"
)
set_target_properties(engine PROPERTIES
VERSION ${PROJECT_VERSION}
SOVERSION ${PROJECT_VERSION_MAJOR}

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp

@@ -98,22 +98,19 @@ U32 inline move_list_score(Move move) {

return history[piece::get_index(type, board.get_side())][to_underlying(move.target())];
}
Move move_list_best_move;
void move_list_sort(MoveList &list, std::vector<int> &index, bool bestCheck = true) {
std::vector<int> move_list_sort(MoveList &list, const Move best) {
static std::vector<int> score(256);
bool best = false;
bool best_found = false;
for (int i = 0; i < list.size(); i++) {
score[i] = move_list_score(list[i]);
index[i] = i;
if (bestCheck && list[i] == move_list_best_move) {
if (list[i] == best) {
score[i] = 30000;
bestCheck = false;
best = true;
best_found = true;
}
}
if (!best && ply && follow_pv) {
if (!best_found && ply && follow_pv) {
follow_pv = false;
for (int i = 0; i < list.size(); i++) {
if (list[i] == pv_table[0][ply]) {

@@ -124,7 +121,10 @@ void move_list_sort(MoveList &list, std::vector<int> &index, bool bestCheck = tr

}
}
sort(index.begin(), index.begin() + list.size(), [&](int a, int b) { return score[a] > score[b]; });
std::vector<int> index(list.size());
std::iota(begin(index), end(index), 0);
sort(begin(index), end(index), [&](int a, int b) { return score[a] > score[b]; });
return index;
}
int evaluate(const Board &board) {

@@ -200,9 +200,7 @@ int quiescence(int16_t alpha, int16_t beta) {

Board copy;
MoveList list(board);
std::vector<int> index(list.size());
move_list_sort(list, index, false);
for (int idx : index) {
for (int idx : move_list_sort(list, Move())) {
if (!stats_move_make(copy, list[idx], 1)) continue;
score = -quiescence(-beta, -alpha);
stats_move_unmake(copy);

@@ -300,11 +298,8 @@ int negamax(int16_t alpha, int16_t beta, uint8_t depth, bool null) {

int legal_moves = 0;
int searched = 0;
move_list_best_move = bestMove;
MoveList list(board);
std::vector<int> index(list.size());
move_list_sort(list, index);
for (int idx : index) {
for (int idx : move_list_sort(list, bestMove)) {
const Move move = list[idx];
if (!stats_move_make(copy, move, 0)) continue;
legal_moves++;

@@ -380,7 +375,7 @@ void search_position(const uci::Settings &settingsr) {

settings = &settingsr;
if (settings->newgame) {
ttable = TTable(C64(0x400000));
ttable = TTable(C64(0x1000000));
}
ply = 0;

diff --git a/src/move/move.hpp b/src/move/move.hpp

@@ -26,7 +26,7 @@ struct Move {

PCQUEEN,
};
Move() = default;
Move() : source_i(0), target_i(0), flags_i(0) {}
Move(Square source, Square target, Flag flags)
: source_i(to_underlying(source)), target_i(to_underlying(target)), flags_i(flags) {}

diff --git a/src/move/movelist.cpp b/src/move/movelist.cpp

@@ -10,17 +10,9 @@

((color == Color::BLACK && source >= Square::a7 && source <= Square::h7) || \
(color == Color::WHITE && source >= Square::a2 && source <= Square::h2))
using piece::Type::BISHOP;
using piece::Type::KING;
using piece::Type::KNIGHT;
using piece::Type::NONE;
using piece::Type::PAWN;
using piece::Type::QUEEN;
using piece::Type::ROOK;
void MoveList::generate(const Board &board) {
this->clear();
uint8_t src_i, tgt_i;
Color color = board.get_side();

diff --git a/src/move/movelist.hpp b/src/move/movelist.hpp

@@ -29,7 +29,6 @@ class MoveList {

private:
void generate(const Board &board);
void clear() { list.clear(); }
list_t list;
};