From: Vizvezdenec <Vizvezdenec@gmail.com>
Date: Thu, 11 Mar 2021 11:51:20 +0000 (+0300)
Subject: Remove advanced_pawn_push()
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=d58e83695f1dbe5bb75ca9e5d6775757b5fd5f7a

Remove advanced_pawn_push()

Continuation of work by @topologist: we now do futility pruning and movecount
pruning in qsearch() for pawn pushes up to the 7th rank. So the condition to
avoid the pruning is if the move is a promotion or not. This allows to get rid
of the advanced_pawn_push() function in position.h alltogether.

Passed STC
https://tests.stockfishchess.org/tests/view/6048c5842433018de7a387e6
LLR: 2.93 (-2.94,2.94) {-1.25,0.25}
Total: 34424 W: 3081 L: 3015 D: 28328
Ptnml(0-2): 110, 2442, 12052, 2488, 120

Passed LTC
https://tests.stockfishchess.org/tests/view/6048f7d22433018de7a387f0
LLR: 2.94 (-2.94,2.94) {-0.75,0.25}
Total: 142024 W: 5170 L: 5202 D: 131652
Ptnml(0-2): 50, 4678, 61613, 4596, 75

Closes https://github.com/official-stockfish/Stockfish/pull/3390

Bench: 4339126
---

diff --git a/src/position.h b/src/position.h
index a7654aa1..d470ef90 100644
--- a/src/position.h
+++ b/src/position.h
@@ -128,7 +128,6 @@ public:
   bool capture(Move m) const;
   bool capture_or_promotion(Move m) const;
   bool gives_check(Move m) const;
-  bool advanced_pawn_push(Move m) const;
   Piece moved_piece(Move m) const;
   Piece captured_piece() const;
 
@@ -310,11 +309,6 @@ inline bool Position::pawn_passed(Color c, Square s) const {
   return !(pieces(~c, PAWN) & passed_pawn_span(c, s));
 }
 
-inline bool Position::advanced_pawn_push(Move m) const {
-  return   type_of(moved_piece(m)) == PAWN
-        && relative_rank(sideToMove, to_sq(m)) > RANK_6;
-}
-
 inline int Position::pawns_on_same_color_squares(Color c, Square s) const {
   return popcount(pieces(c, PAWN) & ((DarkSquares & s) ? DarkSquares : ~DarkSquares));
 }
diff --git a/src/search.cpp b/src/search.cpp
index fa592a85..af7f801f 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1579,7 +1579,7 @@ moves_loop: // When in check, search starts from here
       if (    bestValue > VALUE_TB_LOSS_IN_MAX_PLY
           && !givesCheck
           &&  futilityBase > -VALUE_KNOWN_WIN
-          && !pos.advanced_pawn_push(move))
+          &&  type_of(move) != PROMOTION)
       {
 
           if (moveCount > 2)