Speed up max_piece_type()

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 1bfd9dfd10bba21385fc3dc65ebfcb34bfcc686a..d5a4bb970a954e78379c6917f1752bf8eb4bce43 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -27,7 +27,7 @@
 #include "material.h"
 #include "pawns.h"
 #include "thread.h"
-#include "ucioption.h"
+#include "uci.h"
 
 namespace {
 
@@ -141,8 +141,8 @@ namespace {
   // Threat[attacking][attacked] contains bonuses according to which piece
   // type attacks which one.
   const Score Threat[][PIECE_TYPE_NB] = {
-    { S(0, 0), S( 7, 39), S(24, 49), S(24, 49), S(41,100), S(41,100) }, // Minor
-    { S(0, 0), S(15, 39), S(15, 45), S(15, 45), S(15, 45), S(24, 49) }  // Major
+    { S(0, 0), S(0, 38), S(32, 45), S(32, 45), S(41,100), S(35,104) }, // Minor
+    { S(0, 0), S(7, 28), S(20, 49), S(20, 49), S(8 , 42), S(23, 44) }  // Major
   };
 
   // ThreatenedByPawn[PieceType] contains a penalty according to which piece
@@ -491,6 +491,23 @@ namespace {
   }
 
 
+  // max_piece_type() is a helper function used by evaluate_threats() to get
+  // the value of the biggest PieceType of color C in 'target' bitboard.
+
+  template<Color C>
+  inline PieceType max_piece_type(const Position& pos, const Bitboard target) {
+
+    assert(target & (pos.pieces(C) ^ pos.pieces(C, KING)));
+
+    PieceType pt;
+    for (pt = QUEEN; pt >= KNIGHT; --pt)
+        if (target & pos.pieces(C, pt))
+            break;
+
+    return pt;
+  }
+
+
   // evaluate_threats() assigns bonuses according to the type of attacking piece
   // and the type of attacked one.
 
@@ -499,33 +516,34 @@ namespace {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
+    enum { Minor, Major };
+
     Bitboard b, weakEnemies, protectedEnemies;
     Score score = SCORE_ZERO;
-    enum { Minor, Major };
 
-    // Protected enemies
-    protectedEnemies = (pos.pieces(Them) ^ pos.pieces(Them,PAWN))
-                      & ei.attackedBy[Them][PAWN]
+    // Enemies defended by a pawn and under our attack by a minor piece
+    protectedEnemies =  (pos.pieces(Them) ^ pos.pieces(Them, PAWN))
+                      &  ei.attackedBy[Them][PAWN]
                       & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
 
     if (protectedEnemies)
-        score += Threat[Minor][type_of(pos.piece_on(lsb(protectedEnemies)))];
+        score += Threat[Minor][max_piece_type<Them>(pos, protectedEnemies)];
 
     // Enemies not defended by a pawn and under our attack
-    weakEnemies =  pos.pieces(Them)
+    weakEnemies =   pos.pieces(Them)
                  & ~ei.attackedBy[Them][PAWN]
-                 & ei.attackedBy[Us][ALL_PIECES];
+                 &  ei.attackedBy[Us][ALL_PIECES];
 
     // Add a bonus according if the attacking pieces are minor or major
     if (weakEnemies)
     {
         b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
         if (b)
-            score += Threat[Minor][type_of(pos.piece_on(lsb(b)))];
+            score += Threat[Minor][max_piece_type<Them>(pos, b)];
 
         b = weakEnemies & (ei.attackedBy[Us][ROOK] | ei.attackedBy[Us][QUEEN]);
         if (b)
-            score += Threat[Major][type_of(pos.piece_on(lsb(b)))];
+            score += Threat[Major][max_piece_type<Them>(pos, b)];
 
         b = weakEnemies & ~ei.attackedBy[Them][ALL_PIECES];
         if (b)