// better than the second best move.
const Value EasyMoveMargin = Value(0x200);
- // Problem margin. If the score of the first move at iteration N+1 has
- // dropped by more than this since iteration N, the boolean variable
- // "Problem" is set to true, which will make the program spend some extra
- // time looking for a better move.
- const Value ProblemMargin = Value(0x28);
-
- // No problem margin. If the boolean "Problem" is true, and a new move
- // is found at the root which is less than NoProblemMargin worse than the
- // best move from the previous iteration, Problem is set back to false.
- const Value NoProblemMargin = Value(0x14);
-
// Null move margin. A null move search will not be done if the static
// evaluation of the position is more than NullMoveMargin below beta.
const Value NullMoveMargin = Value(0x200);
int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime, ExactMaxTime;
bool UseTimeManagement, InfiniteSearch, PonderSearch, StopOnPonderhit;
bool AbortSearch, Quit;
- bool FailLow, Problem;
+ bool FailLow;
// Show current line?
bool ShowCurrentLine;
// Initialize global search variables
Idle = StopOnPonderhit = AbortSearch = Quit = false;
- FailLow = Problem = false;
+ FailLow = false;
NodesSincePoll = 0;
SearchStartTime = get_system_time();
ExactMaxTime = maxTime;
if (ss[0].pv[0] != EasyMove)
EasyMove = MOVE_NONE;
- Problem = false;
-
if (UseTimeManagement)
{
// Time to stop?
alpha = -VALUE_INFINITE;
value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0);
-
- // If the value has dropped a lot compared to the last iteration,
- // set the boolean variable Problem to true. This variable is used
- // for time managment: When Problem is true, we try to complete the
- // current iteration before playing a move.
- Problem = ( Iteration >= 2
- && value <= ValueByIteration[Iteration - 1] - ProblemMargin);
-
- if (Problem && StopOnPonderhit)
- StopOnPonderhit = false;
}
else
{
}
if (value > alpha)
alpha = value;
-
- // Reset the global variable Problem to false if the value isn't too
- // far below the final value from the last iteration.
- if (value > ValueByIteration[Iteration - 1] - NoProblemMargin)
- Problem = false;
}
else // MultiPV > 1
{
assert(alpha >= oldAlpha);
FailLow = (alpha == oldAlpha);
+
+ if (FailLow && StopOnPonderhit)
+ StopOnPonderhit = false;
}
// Can we exit fail low loop ?
if (value == value_mate_in(ply + 1))
ss[ply].mateKiller = move;
}
- // If we are at ply 1, and we are searching the first root move at
- // ply 0, set the 'Problem' variable if the score has dropped a lot
- // (from the computer's point of view) since the previous iteration.
- if ( ply == 1
- && Iteration >= 2
- && -value <= ValueByIteration[Iteration-1] - ProblemMargin)
- Problem = true;
}
// Split?
if (value == value_mate_in(sp->ply + 1))
ss[sp->ply].mateKiller = move;
}
- // If we are at ply 1, and we are searching the first root move at
- // ply 0, set the 'Problem' variable if the score has dropped a lot
- // (from the computer's point of view) since the previous iteration.
- if ( sp->ply == 1
- && Iteration >= 2
- && -value <= ValueByIteration[Iteration-1] - ProblemMargin)
- Problem = true;
}
lock_release(&(sp->lock));
}