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Simplify color usage in search.

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define Color us and use this instead of pos.side_to_move() and nmp_odd. The latter allows to clarify the nmp verification criterion.

Tested for no regression:
LLR: 2.95 (-2.94,2.94) [-3.00,1.00]
Total: 76713 W: 15303 L: 15284 D: 46126
http://tests.stockfishchess.org/tests/view/5b046a0d0ebc5914abc12971

No functional change.
This commit is contained in:
Joost VandeVondele
2018-05-22 20:30:58 +02:00
parent 04407e35d6
commit d702203113
3 changed files with 13 additions and 11 deletions
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19
src/search.cpp
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@@ -547,6 +547,7 @@ namespace {
// Step 1. Initialize node
Thread* thisThread = pos.this_thread();
inCheck = pos.checkers();
Color us = pos.side_to_move();
moveCount = captureCount = quietCount = ss->moveCount = 0;
bestValue = -VALUE_INFINITE;
maxValue = VALUE_INFINITE;
@@ -639,7 +640,7 @@ namespace {
else if (!pos.capture_or_promotion(ttMove))
{
int penalty = -stat_bonus(depth);
thisThread->mainHistory[pos.side_to_move()][from_to(ttMove)] << penalty;
thisThread->mainHistory[us][from_to(ttMove)] << penalty;
update_continuation_histories(ss, pos.moved_piece(ttMove), to_sq(ttMove), penalty);
}
}
@@ -749,8 +750,8 @@ namespace {
&& eval >= beta
&& ss->staticEval >= beta - 36 * depth / ONE_PLY + 225
&& !excludedMove
&& pos.non_pawn_material(pos.side_to_move())
&& (ss->ply >= thisThread->nmp_ply || ss->ply % 2 != thisThread->nmp_odd))
&& pos.non_pawn_material(us)
&& (ss->ply > thisThread->nmp_min_ply || us != thisThread->nmp_color))
{
assert(eval - beta >= 0);
@@ -772,17 +773,17 @@ namespace {
if (nullValue >= VALUE_MATE_IN_MAX_PLY)
nullValue = beta;
if (abs(beta) < VALUE_KNOWN_WIN && (depth < 12 * ONE_PLY || thisThread->nmp_ply))
if (abs(beta) < VALUE_KNOWN_WIN && (depth < 12 * ONE_PLY || thisThread->nmp_min_ply))
return nullValue;
// Do verification search at high depths. Disable null move pruning
// for side to move for the first part of the remaining search tree.
thisThread->nmp_ply = ss->ply + 3 * (depth-R) / 4;
thisThread->nmp_odd = ss->ply % 2;
thisThread->nmp_min_ply = ss->ply + 3 * (depth-R) / 4 - 1;
thisThread->nmp_color = us;
Value v = search<NonPV>(pos, ss, beta-1, beta, depth-R, false);
thisThread->nmp_odd = thisThread->nmp_ply = 0;
thisThread->nmp_min_ply = 0;
if (v >= beta)
return nullValue;
@@ -923,7 +924,7 @@ moves_loop: // When in check, search starts from here
// Step 14. Pruning at shallow depth (~170 Elo)
if ( !rootNode
&& pos.non_pawn_material(pos.side_to_move())
&& pos.non_pawn_material(us)
&& bestValue > VALUE_MATED_IN_MAX_PLY)
{
if ( !captureOrPromotion
@@ -1018,7 +1019,7 @@ moves_loop: // When in check, search starts from here
&& !pos.see_ge(make_move(to_sq(move), from_sq(move))))
r -= 2 * ONE_PLY;
ss->statScore = thisThread->mainHistory[~pos.side_to_move()][from_to(move)]
ss->statScore = thisThread->mainHistory[us][from_to(move)]
+ (*contHist[0])[movedPiece][to_sq(move)]
+ (*contHist[1])[movedPiece][to_sq(move)]
+ (*contHist[3])[movedPiece][to_sq(move)]