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Integrate WIN_PAWN_MOVE into the search() loop

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This commit is contained in:
Marco Costalba 2016-05-21 09:27:07 +02:00
parent 4b068d50f6
commit bea98066a0
2 changed files with 42 additions and 51 deletions
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84
src/syzygy/tbprobe.cpp
View file

@ -1210,17 +1210,20 @@ int probe_dtz_table(const Position& pos, WDLScore wdl, ProbeState* result)
// All of this means that during probing, the engine must look at captures and probe
// their results and must probe the position itself. The "best" result of these
// probes is the correct result for the position.
template<bool CheckPawnMoves = false>
WDLScore search(Position& pos, WDLScore alpha, WDLScore beta, ProbeState* result)
{
WDLScore value, epValue = WDLScoreNone;
StateInfo st;
CheckInfo ci(pos);
Move bestMove = MOVE_NONE;
auto moveList = MoveList<LEGAL>(pos);
size_t moveCount = moveList.size();
for (const Move& move : moveList)
{
if (!pos.capture(move))
if ( !pos.capture(move)
&& (!CheckPawnMoves || type_of(pos.moved_piece(move)) != PAWN))
continue;
pos.do_move(move, st, pos.gives_check(move, ci));
@ -1238,10 +1241,16 @@ WDLScore search(Position& pos, WDLScore alpha, WDLScore beta, ProbeState* result
}
if (value >= beta)
return *result = WINNING_CAPTURE, value;
{
*result = (!CheckPawnMoves || pos.capture(move)) ? WIN_CAPTURE : WIN_PAWN_MOVE;
return value;
}
if (value > alpha)
{
alpha = value;
bestMove = move;
}
}
value = probe_wdl_table(pos, result);
@ -1249,78 +1258,59 @@ WDLScore search(Position& pos, WDLScore alpha, WDLScore beta, ProbeState* result
if (*result == FAIL)
return WDLDraw;
// The tables do not contain information on position with ep rights, so in
// TB tables do not contain information on position with ep rights, so in
// this case probe_wdl_table could be wrong. In particular could be higher
// then epValue and if epValue is the only move then we are forced to play
// the losing ep capture.
if (epValue != WDLScoreNone && !moveCount)
value = epValue;
// Here alpha stores the best value out of the previous search
if (value > alpha)
return *result = (value == epValue ? WINNING_CAPTURE : OK), value;
return *result = (value == epValue && value > WDLDraw ? WIN_CAPTURE : OK), value;
return *result = (alpha > WDLDraw ? WINNING_CAPTURE : OK), alpha;
if (bestMove && alpha > WDLDraw)
*result = (!CheckPawnMoves || pos.capture(bestMove)) ? WIN_CAPTURE : WIN_PAWN_MOVE;
else
*result = OK;
return alpha;
}
int probe_dtz(Position& pos, ProbeState *result);
int probe_dtz(Position& pos, ProbeState* result);
// This routine treats a position with en passant captures as one without.
int probe_dtz_no_ep(Position& pos, ProbeState *result)
int probe_dtz_no_ep(Position& pos, ProbeState* result)
{
int dtz;
WDLScore wdl = search(pos, WDLLoss, WDLWin, result);
WDLScore wdl = search<true>(pos, WDLLoss, WDLWin, result);
if (*result == FAIL)
return 0;
if (wdl == WDLDraw) // DTZ tables have no draws
if (wdl == WDLDraw) // DTZ tables don't store draws
return 0;
if (*result == WINNING_CAPTURE) // DTZ tables store random value in this case
return wdl == WDLWin ? 1 : 101;
if ( *result == WIN_CAPTURE // DTZ tables store a 'don't care' value in this case
|| *result == WIN_PAWN_MOVE)
return wdl == WDLWin ? 1 : 101; // DTZ scores for immediate win or cursed win
dtz = 1 + probe_dtz_table(pos, wdl, result); // Probe the table!
if (*result != CHANGE_STM)
{
if (wdl == WDLCursedLoss || wdl == WDLCursedWin)
dtz += 100;
return wdl > WDLDraw ? dtz : -dtz;
}
ExtMove stack[MAX_MOVES];
ExtMove *moves, *end = nullptr;
StateInfo st;
CheckInfo ci(pos);
if (wdl > 0) {
// Generate at least all legal non-capturing pawn moves
// including non-capturing promotions.
if (!pos.checkers())
end = generate<NON_EVASIONS>(pos, stack);
else
end = generate<EVASIONS>(pos, stack);
for (moves = stack; moves < end; ++moves) {
Move move = moves->move;
if ( type_of(pos.moved_piece(move)) != PAWN
|| pos.capture(move)
|| !pos.legal(move, ci.pinned))
continue;
pos.do_move(move, st, pos.gives_check(move, ci));
WDLScore v = -search(pos, WDLLoss, -wdl + WDLCursedWin, result);
pos.undo_move(move);
if (*result == FAIL)
return 0;
if (v == wdl)
return v == WDLWin ? 1 : 101;
}
}
dtz = 1 + probe_dtz_table(pos, wdl, result);
if (*result >= 0) {
if (wdl & 1) dtz += 100;
return wdl >= 0 ? dtz : -dtz;
}
if (wdl > 0) {
int best = 0xffff;

9
src/syzygy/tbprobe.h
View file

@ -36,10 +36,11 @@ enum WDLScore {
// Possible states after a probing operation
enum ProbeState {
FAIL = 0, // Probe failed (missing file table)
OK = 1, // Probe succesful
CHANGE_STM = -1, // WDL probe succesful but DTZ should check the other side
WINNING_CAPTURE = 2 // WDL probe succesful but position's DTZ value is invalid
FAIL = 0, // Probe failed (missing file table)
OK = 1, // Probe succesful
CHANGE_STM = -1, // WDL probe succesful but DTZ should check the other side
WIN_CAPTURE = 2, // WDL probe succesful but position's DTZ value is invalid
WIN_PAWN_MOVE = 3 // WDL probe succesful but position's DTZ value is invalid
};
extern size_t MaxCardinality;