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) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
if ( !PvNode
&& eval >= beta
&& ss->staticEval >= beta - 36 * depth / ONE_PLY + 225
- && (ss->ply >= thisThread->nmp_ply || ss->ply % 2 == thisThread->pair))
+ && (ss->ply >= thisThread->nmp_ply || ss->ply % 2 != thisThread->nmp_odd))
{
assert(eval - beta >= 0);
if (nullValue >= VALUE_MATE_IN_MAX_PLY)
nullValue = beta;
- if (depth < 12 * ONE_PLY && abs(beta) < VALUE_KNOWN_WIN)
+ if (abs(beta) < VALUE_KNOWN_WIN && (depth < 12 * ONE_PLY || thisThread->nmp_ply))
return nullValue;
// Do verification search at high depths
- R += ONE_PLY;
// disable null move pruning for side to move for the first part of the remaining search tree
- int nmp_ply = thisThread->nmp_ply;
- int pair = thisThread->pair;
thisThread->nmp_ply = ss->ply + 3 * (depth-R) / 4;
- thisThread->pair = (ss->ply % 2) == 0;
+ thisThread->nmp_odd = ss->ply % 2;
Value v = depth-R < ONE_PLY ? qsearch<NonPV, false>(pos, ss, beta-1, beta)
: search<NonPV>(pos, ss, beta-1, beta, depth-R, false, true);
- thisThread->pair = pair;
- thisThread->nmp_ply = nmp_ply;
+
+ thisThread->nmp_odd = thisThread->nmp_ply = 0;
if (v >= beta)
return nullValue;
if (Threads.ponder)
return;
- if ( (Limits.use_time_management() && elapsed > Time.maximum())
+ if ( (Limits.use_time_management() && elapsed > Time.maximum() - 10)
|| (Limits.movetime && elapsed >= Limits.movetime)
|| (Limits.nodes && Threads.nodes_searched() >= (uint64_t)Limits.nodes))
Threads.stop = true;