From: Marco Costalba <mcostalba@gmail.com>
Date: Mon, 29 Jul 2013 17:01:50 +0000 (+0200)
Subject: Speed up move generation
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=28bc8ed4620df5cb12803ef96e61e2e4aad700ba

Speed up move generation

Pass the color as template parameter
to generate_all()

Speedup of 1,3% in perft and 2,5% in bench !

No functional change.
---

diff --git a/src/movegen.cpp b/src/movegen.cpp
index b4e089a8..fab5e461 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -221,7 +221,7 @@ namespace {
                 && !(PseudoAttacks[Pt][from] & target & ci->checkSq[Pt]))
                 continue;
 
-            if (ci->dcCandidates && (ci->dcCandidates & from))
+            if (unlikely(ci->dcCandidates) && (ci->dcCandidates & from))
                 continue;
         }
 
@@ -237,38 +237,36 @@ namespace {
   }
 
 
-  template<GenType Type> FORCE_INLINE
-  ExtMove* generate_all(const Position& pos, ExtMove* mlist, Color us,
-                        Bitboard target, const CheckInfo* ci = NULL) {
+  template<Color Us, GenType Type> FORCE_INLINE
+  ExtMove* generate_all(const Position& pos, ExtMove* mlist, Bitboard target,
+                        const CheckInfo* ci = NULL) {
 
     const bool Checks = Type == QUIET_CHECKS;
 
-    mlist = (us == WHITE ? generate_pawn_moves<WHITE, Type>(pos, mlist, target, ci)
-                         : generate_pawn_moves<BLACK, Type>(pos, mlist, target, ci));
-
-    mlist = generate_moves<KNIGHT, Checks>(pos, mlist, us, target, ci);
-    mlist = generate_moves<BISHOP, Checks>(pos, mlist, us, target, ci);
-    mlist = generate_moves<ROOK,   Checks>(pos, mlist, us, target, ci);
-    mlist = generate_moves<QUEEN,  Checks>(pos, mlist, us, target, ci);
+    mlist = generate_pawn_moves<Us, Type>(pos, mlist, target, ci);
+    mlist = generate_moves<KNIGHT, Checks>(pos, mlist, Us, target, ci);
+    mlist = generate_moves<BISHOP, Checks>(pos, mlist, Us, target, ci);
+    mlist = generate_moves<  ROOK, Checks>(pos, mlist, Us, target, ci);
+    mlist = generate_moves< QUEEN, Checks>(pos, mlist, Us, target, ci);
 
     if (Type != QUIET_CHECKS && Type != EVASIONS)
     {
-        Square from = pos.king_square(us);
+        Square from = pos.king_square(Us);
         Bitboard b = pos.attacks_from<KING>(from) & target;
         SERIALIZE(b);
     }
 
-    if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(us))
+    if (Type != CAPTURES && Type != EVASIONS && pos.can_castle(Us))
     {
         if (pos.is_chess960())
         {
-            mlist = generate_castle<KING_SIDE,  Checks, true>(pos, mlist, us);
-            mlist = generate_castle<QUEEN_SIDE, Checks, true>(pos, mlist, us);
+            mlist = generate_castle< KING_SIDE, Checks, true>(pos, mlist, Us);
+            mlist = generate_castle<QUEEN_SIDE, Checks, true>(pos, mlist, Us);
         }
         else
         {
-            mlist = generate_castle<KING_SIDE,  Checks, false>(pos, mlist, us);
-            mlist = generate_castle<QUEEN_SIDE, Checks, false>(pos, mlist, us);
+            mlist = generate_castle< KING_SIDE, Checks, false>(pos, mlist, Us);
+            mlist = generate_castle<QUEEN_SIDE, Checks, false>(pos, mlist, Us);
         }
     }
 
@@ -300,7 +298,8 @@ ExtMove* generate(const Position& pos, ExtMove* mlist) {
                   : Type == QUIETS       ? ~pos.pieces()
                   : Type == NON_EVASIONS ? ~pos.pieces(us) : 0;
 
-  return generate_all<Type>(pos, mlist, us, target);
+  return us == WHITE ? generate_all<WHITE, Type>(pos, mlist, target)
+                     : generate_all<BLACK, Type>(pos, mlist, target);
 }
 
 // Explicit template instantiations
@@ -316,6 +315,7 @@ ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* mlist) {
 
   assert(!pos.checkers());
 
+  Color us = pos.side_to_move();
   CheckInfo ci(pos);
   Bitboard dc = ci.dcCandidates;
 
@@ -335,7 +335,8 @@ ExtMove* generate<QUIET_CHECKS>(const Position& pos, ExtMove* mlist) {
      SERIALIZE(b);
   }
 
-  return generate_all<QUIET_CHECKS>(pos, mlist, pos.side_to_move(), ~pos.pieces(), &ci);
+  return us == WHITE ? generate_all<WHITE, QUIET_CHECKS>(pos, mlist, ~pos.pieces(), &ci)
+                     : generate_all<BLACK, QUIET_CHECKS>(pos, mlist, ~pos.pieces(), &ci);
 }
 
 
@@ -395,7 +396,8 @@ ExtMove* generate<EVASIONS>(const Position& pos, ExtMove* mlist) {
   // Generate blocking evasions or captures of the checking piece
   Bitboard target = between_bb(checksq, ksq) | checksq;
 
-  return generate_all<EVASIONS>(pos, mlist, us, target);
+  return us == WHITE ? generate_all<WHITE, EVASIONS>(pos, mlist, target)
+                     : generate_all<BLACK, EVASIONS>(pos, mlist, target);
 }