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Move ONE_PLY to be 1 instead of 2: search() 

Now that half-plies are no more used we can simplify
the code assuming that ONE_PLY is 1 and no more 2.

Verified with a SMP test:
LLR: 2.95 (-2.94,2.94) [-4.50,0.00]
Total: 8926 W: 1712 L: 1607 D: 5607

No functional change.
pull/56/head
Marco Costalba 2014-09-29 14:08:56 +02:00
parent 27a1877299
commit 222f59b9c1
2 changed files with 34 additions and 37 deletions
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59
src/search.cpp
View File

@ -55,21 +55,20 @@ namespace {
enum NodeType { Root, PV, NonPV };
// Dynamic razoring margin based on depth
inline Value razor_margin(Depth d) { return Value(512 + 16 * d); }
inline Value razor_margin(Depth d) { return Value(512 + 32 * d); }
// Futility lookup tables (initialized at startup) and their access functions
int FutilityMoveCounts[2][32]; // [improving][depth]
inline Value futility_margin(Depth d) {
return Value(100 * d);
return Value(200 * d);
}
// Reduction lookup tables (initialized at startup) and their access function
int8_t Reductions[2][2][64][64]; // [pv][improving][depth][moveNumber]
template <bool PvNode> inline Depth reduction(bool i, Depth d, int mn) {
return (Depth) Reductions[PvNode][i][std::min(int(d) / ONE_PLY, 63)][std::min(mn, 63)];
return (Depth) Reductions[PvNode][i][std::min(int(d), 63)][std::min(mn, 63)];
}
size_t PVIdx;
@ -127,21 +126,21 @@ void Search::init() {
{
double pvRed = 0.00 + log(double(hd)) * log(double(mc)) / 3.00;
double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25;
Reductions[1][1][hd][mc] = int8_t( pvRed >= 1.0 ? pvRed+0.5: 0)*int(ONE_PLY);
Reductions[0][1][hd][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed+0.5: 0)*int(ONE_PLY);
Reductions[1][1][hd][mc] = int8_t( pvRed >= 1.0 ? pvRed + 0.5: 0);
Reductions[0][1][hd][mc] = int8_t(nonPVRed >= 1.0 ? nonPVRed + 0.5: 0);
Reductions[1][0][hd][mc] = Reductions[1][1][hd][mc];
Reductions[0][0][hd][mc] = Reductions[0][1][hd][mc];
if (Reductions[0][0][hd][mc] >= 2 * ONE_PLY)
Reductions[0][0][hd][mc] += ONE_PLY;
if (Reductions[0][0][hd][mc] >= 2)
Reductions[0][0][hd][mc] += 1;
}
// Init futility move count array
for (d = 0; d < 32; ++d)
{
FutilityMoveCounts[0][d] = int(2.4 + 0.222 * pow(d + 0.00, 1.8));
FutilityMoveCounts[1][d] = int(3.0 + 0.300 * pow(d + 0.98, 1.8));
FutilityMoveCounts[0][d] = int(2.4 + 0.222 * pow(d * 2 + 0.00, 1.8));
FutilityMoveCounts[1][d] = int(3.0 + 0.300 * pow(d * 2 + 0.98, 1.8));
}
}
@ -154,7 +153,7 @@ uint64_t Search::perft(Position& pos, Depth depth) {
StateInfo st;
uint64_t cnt, nodes = 0;
CheckInfo ci(pos);
const bool leaf = depth == 2 * ONE_PLY;
const bool leaf = (depth == 2 * ONE_PLY);
for (MoveList<LEGAL> it(pos); *it; ++it)
{
@ -561,8 +560,7 @@ namespace {
assert(eval - beta >= 0);
// Null move dynamic reduction based on depth and value
Depth R = (3 + (depth / 8 )) * ONE_PLY
+ std::min(int(eval - beta) / PawnValueMg, 3) * ONE_PLY;
Depth R = (3 + depth / 4 + std::min(int(eval - beta) / PawnValueMg, 3)) * ONE_PLY;
pos.do_null_move(st);
(ss+1)->skipNullMove = true;
@ -627,10 +625,9 @@ namespace {
&& !ttMove
&& (PvNode || ss->staticEval + 256 >= beta))
{
Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4);
d = (d / 2) * 2; // Round to nearest full-ply
Depth d = 2 * (depth - 2 * ONE_PLY) - (PvNode ? DEPTH_ZERO : depth / 2);
ss->skipNullMove = true;
search<PvNode ? PV : NonPV, false>(pos, ss, alpha, beta, d, true);
search<PvNode ? PV : NonPV, false>(pos, ss, alpha, beta, d / 2, true);
ss->skipNullMove = false;
tte = TT.probe(posKey);
@ -696,7 +693,7 @@ moves_loop: // When in check and at SpNode search starts from here
Signals.firstRootMove = (moveCount == 1);
if (thisThread == Threads.main() && Time::now() - SearchTime > 3000)
sync_cout << "info depth " << depth / ONE_PLY
sync_cout << "info depth " << depth
<< " currmove " << move_to_uci(move, pos.is_chess960())
<< " currmovenumber " << moveCount + PVIdx << sync_endl;
}
@ -726,10 +723,10 @@ moves_loop: // When in check and at SpNode search starts from here
&& !ext
&& pos.legal(move, ci.pinned))
{
Value rBeta = ttValue - int(depth);
Value rBeta = ttValue - int(2 * depth);
ss->excludedMove = move;
ss->skipNullMove = true;
value = search<NonPV, false>(pos, ss, rBeta - 1, rBeta, (depth / 4) * 2, cutNode);
value = search<NonPV, false>(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode);
ss->skipNullMove = false;
ss->excludedMove = MOVE_NONE;
@ -750,7 +747,7 @@ moves_loop: // When in check and at SpNode search starts from here
{
// Move count based pruning
if ( depth < 16 * ONE_PLY
&& moveCount >= FutilityMoveCounts[improving][depth] )
&& moveCount >= FutilityMoveCounts[improving][depth])
{
if (SpNode)
splitPoint->mutex.lock();
@ -763,8 +760,8 @@ moves_loop: // When in check and at SpNode search starts from here
// Futility pruning: parent node
if (predictedDepth < 7 * ONE_PLY)
{
futilityValue = ss->staticEval + futility_margin(predictedDepth)
+ 128 + Gains[pos.moved_piece(move)][to_sq(move)];
futilityValue = ss->staticEval + futility_margin(predictedDepth)
+ 128 + Gains[pos.moved_piece(move)][to_sq(move)];
if (futilityValue <= alpha)
{
@ -855,20 +852,20 @@ moves_loop: // When in check and at SpNode search starts from here
if (SpNode)
alpha = splitPoint->alpha;
value = newDepth < ONE_PLY ?
givesCheck ? -qsearch<NonPV, true>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
: -qsearch<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
: - search<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode);
value = newDepth < ONE_PLY ?
givesCheck ? -qsearch<NonPV, true>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
: -qsearch<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, DEPTH_ZERO)
: - search<NonPV, false>(pos, ss+1, -(alpha+1), -alpha, newDepth, !cutNode);
}
// For PV nodes only, do a full PV search on the first move or after a fail
// high (in the latter case search only if value < beta), otherwise let the
// parent node fail low with value <= alpha and to try another move.
if (PvNode && (pvMove || (value > alpha && (RootNode || value < beta))))
value = newDepth < ONE_PLY ?
givesCheck ? -qsearch<PV, true>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: -qsearch<PV, false>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: - search<PV, false>(pos, ss+1, -beta, -alpha, newDepth, false);
value = newDepth < ONE_PLY ?
givesCheck ? -qsearch<PV, true>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: -qsearch<PV, false>(pos, ss+1, -beta, -alpha, DEPTH_ZERO)
: - search<PV, false>(pos, ss+1, -beta, -alpha, newDepth, false);
// Step 17. Undo move
pos.undo_move(move);
@ -1229,7 +1226,7 @@ moves_loop: // When in check and at SpNode search starts from here
// Increase history value of the cut-off move and decrease all the other
// played quiet moves.
Value bonus = Value(int(depth) * int(depth));
Value bonus = Value(4 * int(depth) * int(depth));
History.update(pos.moved_piece(move), to_sq(move), bonus);
for (int i = 0; i < quietsCnt; ++i)
{

12
src/types.h
View File

@ -211,14 +211,14 @@ enum Piece {
enum Depth {
ONE_PLY = 2,
ONE_PLY = 1,
DEPTH_ZERO = 0 * ONE_PLY,
DEPTH_QS_CHECKS = 0 * ONE_PLY,
DEPTH_QS_NO_CHECKS = -1 * ONE_PLY,
DEPTH_QS_RECAPTURES = -5 * ONE_PLY,
DEPTH_ZERO = 0,
DEPTH_QS_CHECKS = 0,
DEPTH_QS_NO_CHECKS = -1,
DEPTH_QS_RECAPTURES = -5,
DEPTH_NONE = -6 * ONE_PLY
DEPTH_NONE = -6
};
enum Square {