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Clarify when forcing the moves loop

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In some cases we want to go direcly to the moves loop
without checking for early return. The patch make this
logic more clear and consistent.

Tested for no regression, passed STC
LLR: 2.96 (-2.94,2.94) [-3.00,1.00]
Total: 25282 W: 5136 L: 5022 D: 15124

and LTC
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 72007 W: 12133 L: 12095 D: 47779

bench: 9316798
This commit is contained in:
Marco Costalba
2014-12-08 09:46:21 +01:00
parent 158864270a
commit 589c711449
2 changed files with 13 additions and 13 deletions
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24
src/search.cpp
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@@ -514,7 +514,7 @@ namespace {
assert(0 <= ss->ply && ss->ply < MAX_PLY);
ss->currentMove = ss->ttMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
(ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
(ss+1)->skipEarlyPruning = false; (ss+1)->reduction = DEPTH_ZERO;
(ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
// Step 4. Transposition table lookup
@@ -599,6 +599,9 @@ namespace {
TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval);
}
if (ss->skipEarlyPruning)
goto moves_loop;
if ( !pos.captured_piece_type()
&& ss->staticEval != VALUE_NONE
&& (ss-1)->staticEval != VALUE_NONE
@@ -629,7 +632,6 @@ namespace {
// Step 7. Futility pruning: child node (skipped when in check)
if ( !PvNode
&& !ss->skipNullMove
&& depth < 7 * ONE_PLY
&& eval - futility_margin(depth) >= beta
&& eval < VALUE_KNOWN_WIN // Do not return unproven wins
@@ -638,7 +640,6 @@ namespace {
// Step 8. Null move search with verification search (is omitted in PV nodes)
if ( !PvNode
&& !ss->skipNullMove
&& depth >= 2 * ONE_PLY
&& eval >= beta
&& pos.non_pawn_material(pos.side_to_move()))
@@ -651,10 +652,10 @@ namespace {
Depth R = (3 + depth / 4 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
pos.do_null_move(st);
(ss+1)->skipNullMove = true;
(ss+1)->skipEarlyPruning = true;
nullValue = depth-R < ONE_PLY ? -qsearch<NonPV, false>(pos, ss+1, -beta, -beta+1, DEPTH_ZERO)
: - search<NonPV, false>(pos, ss+1, -beta, -beta+1, depth-R, !cutNode);
(ss+1)->skipNullMove = false;
(ss+1)->skipEarlyPruning = false;
pos.undo_null_move();
if (nullValue >= beta)
@@ -667,10 +668,10 @@ namespace {
return nullValue;
// Do verification search at high depths
ss->skipNullMove = true;
ss->skipEarlyPruning = true;
Value v = depth-R < ONE_PLY ? qsearch<NonPV, false>(pos, ss, beta-1, beta, DEPTH_ZERO)
: search<NonPV, false>(pos, ss, beta-1, beta, depth-R, false);
ss->skipNullMove = false;
ss->skipEarlyPruning = false;
if (v >= beta)
return nullValue;
@@ -683,7 +684,6 @@ namespace {
// prune the previous move.
if ( !PvNode
&& depth >= 5 * ONE_PLY
&& !ss->skipNullMove
&& abs(beta) < VALUE_MATE_IN_MAX_PLY)
{
Value rbeta = std::min(beta + 200, VALUE_INFINITE);
@@ -714,9 +714,9 @@ namespace {
&& (PvNode || ss->staticEval + 256 >= beta))
{
Depth d = 2 * (depth - 2 * ONE_PLY) - (PvNode ? DEPTH_ZERO : depth / 2);
ss->skipNullMove = true;
ss->skipEarlyPruning = true;
search<PvNode ? PV : NonPV, false>(pos, ss, alpha, beta, d / 2, true);
ss->skipNullMove = false;
ss->skipEarlyPruning = false;
tte = TT.probe(posKey);
ttMove = tte ? tte->move() : MOVE_NONE;
@@ -816,9 +816,9 @@ moves_loop: // When in check and at SpNode search starts from here
{
Value rBeta = ttValue - 2 * depth / ONE_PLY;
ss->excludedMove = move;
ss->skipNullMove = true;
ss->skipEarlyPruning = true;
value = search<NonPV, false>(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode);
ss->skipNullMove = false;
ss->skipEarlyPruning = false;
ss->excludedMove = MOVE_NONE;
if (value < rBeta)