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Assorted trivial cleanups (July 2019)

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No functional change
This commit is contained in:
Alain SAVARD
2019-08-14 22:15:41 +02:00
committed by Stéphane Nicolet
parent 66a3c2968b
commit 7efc39d683
7 changed files with 31 additions and 27 deletions
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19
src/search.cpp
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@@ -102,15 +102,16 @@ namespace {
Move best = MOVE_NONE;
};
// Breadcrumbs are used to mark nodes as being searched by a given thread.
// Breadcrumbs are used to mark nodes as being searched by a given thread
struct Breadcrumb {
std::atomic<Thread*> thread;
std::atomic<Key> key;
};
std::array<Breadcrumb, 1024> breadcrumbs;
// ThreadHolding keeps track of which thread left breadcrumbs at the given node for potential reductions.
// A free node will be marked upon entering the moves loop, and unmarked upon leaving that loop, by the ctor/dtor of this struct.
// ThreadHolding structure keeps track of which thread left breadcrumbs at the given
// node for potential reductions. A free node will be marked upon entering the moves
// loop by the constructor, and unmarked upon leaving that loop by the destructor.
struct ThreadHolding {
explicit ThreadHolding(Thread* thisThread, Key posKey, int ply) {
location = ply < 8 ? &breadcrumbs[posKey & (breadcrumbs.size() - 1)] : nullptr;
@@ -118,7 +119,7 @@ namespace {
owning = false;
if (location)
{
// see if another already marked this location, if not, mark it ourselves.
// See if another already marked this location, if not, mark it ourselves
Thread* tmp = (*location).thread.load(std::memory_order_relaxed);
if (tmp == nullptr)
{
@@ -133,7 +134,7 @@ namespace {
}
~ThreadHolding() {
if (owning) // free the marked location.
if (owning) // Free the marked location
(*location).thread.store(nullptr, std::memory_order_relaxed);
}
@@ -647,9 +648,9 @@ namespace {
// statScore of the previous grandchild. This influences the reduction rules in
// LMR which are based on the statScore of parent position.
if (rootNode)
(ss + 4)->statScore = 0;
(ss+4)->statScore = 0;
else
(ss + 2)->statScore = 0;
(ss+2)->statScore = 0;
// Step 4. Transposition table lookup. We don't want the score of a partial
// search to overwrite a previous full search TT value, so we use a different
@@ -680,7 +681,7 @@ namespace {
// Extra penalty for early quiet moves of the previous ply
if ((ss-1)->moveCount <= 2 && !pos.captured_piece())
update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY));
}
// Penalty for a quiet ttMove that fails low
else if (!pos.capture_or_promotion(ttMove))
@@ -908,7 +909,7 @@ moves_loop: // When in check, search starts from here
moveCountPruning = false;
ttCapture = ttMove && pos.capture_or_promotion(ttMove);
// Mark this node as being searched.
// Mark this node as being searched
ThreadHolding th(thisThread, posKey, ss->ply);
// Step 12. Loop through all pseudo-legal moves until no moves remain