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Highlight that alpha and beta could change in root_search() 

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
sf_2.3.1_base
Marco Costalba 2010-03-06 18:17:04 +01:00
parent f23a9e8f88
commit 4ef068a506
1 changed files with 12 additions and 12 deletions
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24
src/search.cpp
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@ -282,7 +282,7 @@ namespace {
/// Local functions
Value id_loop(const Position& pos, Move searchMoves[]);
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta);
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value* alphaPtr, Value* betaPtr);
Value search_pv(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
Value search(Position& pos, SearchStack ss[], Value beta, Depth depth, int ply, bool allowNullmove, int threadID, Move excludedMove = MOVE_NONE);
Value qsearch(Position& pos, SearchStack ss[], Value alpha, Value beta, Depth depth, int ply, int threadID);
@ -665,8 +665,8 @@ namespace {
beta = Min(ValueByIteration[Iteration - 1] + AspirationDelta, VALUE_INFINITE);
}
// Search to the current depth, rml is updated and sorted
value = root_search(p, ss, rml, alpha, beta);
// Search to the current depth, rml is updated and sorted, alpha and beta could change
value = root_search(p, ss, rml, &alpha, &beta);
// Write PV to transposition table, in case the relevant entries have
// been overwritten during the search.
@ -786,18 +786,19 @@ namespace {
// scheme, prints some information to the standard output and handles
// the fail low/high loops.
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value& oldAlpha, Value& beta) {
Value root_search(Position& pos, SearchStack ss[], RootMoveList& rml, Value* alphaPtr, Value* betaPtr) {
EvalInfo ei;
StateInfo st;
int64_t nodes;
Move move;
Depth depth, ext, newDepth;
Value value, alpha;
Value value, alpha, beta;
bool isCheck, moveIsCheck, captureOrPromotion, dangerous;
int researchCount = 0;
alpha = *alphaPtr;
beta = *betaPtr;
CheckInfo ci(pos);
alpha = oldAlpha;
isCheck = pos.is_check();
// Step 1. Initialize node and poll (omitted at root, but I can see no good reason for this, FIXME)
@ -930,7 +931,7 @@ namespace {
// Prepare for a research after a fail high, each time with a wider window
researchCount++;
beta = Min(beta + AspirationDelta * (1 << researchCount), VALUE_INFINITE);
*betaPtr = beta = Min(beta + AspirationDelta * (1 << researchCount), VALUE_INFINITE);
} // End of fail high loop
@ -1002,22 +1003,21 @@ namespace {
}
} // PV move or new best move
assert(alpha >= oldAlpha);
assert(alpha >= *alphaPtr);
AspirationFailLow = (alpha == oldAlpha);
AspirationFailLow = (alpha == *alphaPtr);
if (AspirationFailLow && StopOnPonderhit)
StopOnPonderhit = false;
}
// Can we exit fail low loop ?
if (AbortSearch || alpha > oldAlpha)
if (AbortSearch || !AspirationFailLow)
break;
// Prepare for a research after a fail low, each time with a wider window
researchCount++;
alpha = Max(alpha - AspirationDelta * (1 << researchCount), -VALUE_INFINITE);
oldAlpha = alpha;
*alphaPtr = alpha = Max(alpha - AspirationDelta * (1 << researchCount), -VALUE_INFINITE);
} // Fail low loop