Better naming and document some endgame functions

In particular the generic scaling functions.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba
2009-08-13 12:45:35 +02:00
parent fd12e8cb23
commit bfd4421f49
4 changed files with 37 additions and 46 deletions

View File

@@ -30,6 +30,7 @@
using namespace std;
////
//// Local definitions
////
@@ -49,14 +50,17 @@ namespace {
{ 0, 0, 0, 0, 0, 0 }, { -5, 0, 0, 0, 0, 0 }, { -33, 23, 0, 0, 0, 0 },
{ 17, 25, -3, 0, 0, 0 }, { 10, -2, -19, -67, 0, 0 }, { 69, 64, -41, 116, 137, 0 } };
// Unmapped endgame evaluation and scaling functions, these
// Named endgame evaluation and scaling functions, these
// are accessed direcly and not through the function maps.
EvaluationFunction<KmmKm> EvaluateKmmKm(WHITE);
EvaluationFunction<KXK> EvaluateKXK(WHITE), EvaluateKKX(BLACK);
ScalingFunction<KBPK> ScaleKBPK(WHITE), ScaleKKBP(BLACK);
ScalingFunction<KQKRP> ScaleKQKRP(WHITE), ScaleKRPKQ(BLACK);
ScalingFunction<KBPsK> ScaleKBPsK(WHITE), ScaleKKBPs(BLACK);
ScalingFunction<KQKRPs> ScaleKQKRPs(WHITE), ScaleKRPsKQ(BLACK);
ScalingFunction<KPsK> ScaleKPsK(WHITE), ScaleKKPs(BLACK);
ScalingFunction<KPKP> ScaleKPKPw(WHITE), ScaleKPKPb(BLACK);
typedef EndgameEvaluationFunctionBase EF;
typedef EndgameScalingFunctionBase SF;
}
@@ -64,11 +68,10 @@ namespace {
//// Classes
////
typedef EndgameEvaluationFunctionBase EF;
typedef EndgameScalingFunctionBase SF;
/// See header for a class description. It is declared here to avoid
/// to include <map> in the header file.
/// EndgameFunctions class stores endgame evaluation and scaling functions
/// in two std::map. Because STL library is not guaranteed to be thread
/// safe even for read access, the maps, although with identical content,
/// are replicated for each thread. This is faster then using locks.
class EndgameFunctions {
public:
@@ -82,10 +85,10 @@ private:
static Key buildKey(const string& keyCode);
static const string swapColors(const string& keyCode);
// Here we store two maps, one for evaluate and one for scaling
// Here we store two maps, for evaluate and scaling functions
pair<map<Key, EF*>, map<Key, SF*> > maps;
// Maps accessing functions for const and non-const references
// Maps accessing functions returning const and non-const references
template<typename T> const map<Key, T*>& get() const { return maps.first; }
template<typename T> map<Key, T*>& get() { return maps.first; }
};
@@ -103,25 +106,22 @@ EndgameFunctions::get<SF>() { return maps.second; }
//// Functions
////
/// Constructor for the MaterialInfoTable class
/// MaterialInfoTable c'tor and d'tor, called once by each thread
MaterialInfoTable::MaterialInfoTable(unsigned int numOfEntries) {
size = numOfEntries;
entries = new MaterialInfo[size];
funcs = new EndgameFunctions();
if (!entries || !funcs)
{
cerr << "Failed to allocate " << (numOfEntries * sizeof(MaterialInfo))
cerr << "Failed to allocate " << numOfEntries * sizeof(MaterialInfo)
<< " bytes for material hash table." << endl;
Application::exit_with_failure();
}
}
/// Destructor for the MaterialInfoTable class
MaterialInfoTable::~MaterialInfoTable() {
delete funcs;
@@ -175,8 +175,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
&& pos.rooks() == EmptyBoardBB
&& pos.queens() == EmptyBoardBB)
{
// Minor piece endgame with at least one minor piece per side,
// and no pawns.
// Minor piece endgame with at least one minor piece per side and
// no pawns. Note that the case KmmK is already handled by KXK.
assert(pos.knights(WHITE) | pos.bishops(WHITE));
assert(pos.knights(BLACK) | pos.bishops(BLACK));
@@ -203,29 +203,32 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
return mi;
}
// Generic scaling functions that refer to more then one material
// distribution. Should be probed after the specialized ones.
// Note that these ones don't return after setting the function.
if ( pos.non_pawn_material(WHITE) == BishopValueMidgame
&& pos.piece_count(WHITE, BISHOP) == 1
&& pos.piece_count(WHITE, PAWN) >= 1)
mi->scalingFunction[WHITE] = &ScaleKBPK;
mi->scalingFunction[WHITE] = &ScaleKBPsK;
if ( pos.non_pawn_material(BLACK) == BishopValueMidgame
&& pos.piece_count(BLACK, BISHOP) == 1
&& pos.piece_count(BLACK, PAWN) >= 1)
mi->scalingFunction[BLACK] = &ScaleKKBP;
mi->scalingFunction[BLACK] = &ScaleKKBPs;
if ( pos.piece_count(WHITE, PAWN) == 0
&& pos.non_pawn_material(WHITE) == QueenValueMidgame
&& pos.piece_count(WHITE, QUEEN) == 1
&& pos.piece_count(BLACK, ROOK) == 1
&& pos.piece_count(BLACK, PAWN) >= 1)
mi->scalingFunction[WHITE] = &ScaleKQKRP;
mi->scalingFunction[WHITE] = &ScaleKQKRPs;
else if ( pos.piece_count(BLACK, PAWN) == 0
&& pos.non_pawn_material(BLACK) == QueenValueMidgame
&& pos.piece_count(BLACK, QUEEN) == 1
&& pos.piece_count(WHITE, ROOK) == 1
&& pos.piece_count(WHITE, PAWN) >= 1)
mi->scalingFunction[BLACK] = &ScaleKRPKQ;
mi->scalingFunction[BLACK] = &ScaleKRPsKQ;
if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == Value(0))
{
@@ -241,6 +244,8 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
}
else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
{
// This is a special case because we set scaling functions
// for both colors instead of only one.
mi->scalingFunction[WHITE] = &ScaleKPKPw;
mi->scalingFunction[BLACK] = &ScaleKPKPb;
}
@@ -298,11 +303,12 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
if (pieceCount[c][ROOK] >= 1)
matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty);
them = opposite_color(c);
// Second-degree polynomial material imbalance by Tord Romstad
//
// We use NO_PIECE_TYPE as a place holder for the bishop pair "extended piece",
// this allow us to be more flexible in defining bishop pair bonuses.
them = opposite_color(c);
for (int pt1 = NO_PIECE_TYPE; pt1 <= QUEEN; pt1++)
{
int c1 = sign * pieceCount[c][pt1];
@@ -318,18 +324,12 @@ MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
}
}
}
mi->value = int16_t(matValue / 16);
return mi;
}
/// EndgameFunctions member definitions. This class is used to store the maps
/// of end game and scaling functions that MaterialInfoTable will query for
/// each key. The maps are constant and are populated only at construction,
/// but are per-thread instead of globals to avoid expensive locks needed
/// because std::map is not guaranteed to be thread-safe even if accessed
/// only for a lookup.
/// EndgameFunctions member definitions.
EndgameFunctions::EndgameFunctions() {
@@ -368,8 +368,8 @@ Key EndgameFunctions::buildKey(const string& keyCode) {
stringstream s;
bool upcase = false;
// Build up a fen substring with the given pieces, note
// that the fen string could be of an illegal position.
// Build up a fen string with the given pieces, note that
// the fen string could be of an illegal position.
for (size_t i = 0; i < keyCode.length(); i++)
{
if (keyCode[i] == 'K')