X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fvalue.h;h=fec6516a4c8c4014427afeeb3cf22d6b9941d865;hp=269102412cb8250ea83dac2c60457eb6c6526ece;hb=0973cc2ef63060294f790803e0525b66ee91dfee;hpb=15ec3e911e231bd992c2e3cf3f7785db6e29f20b

diff --git a/src/value.h b/src/value.h
index 26910241..fec6516a 100644
--- a/src/value.h
+++ b/src/value.h
@@ -52,46 +52,31 @@ enum Value {
 };
 
 
-/// Score struct keeps a midgame and an endgame value in a single
-/// ScoreValue 64 bit union.
-
-union ScoreValue {
-    int64_t v64;
-    struct {
-      int32_t mgv;
-      int32_t egv;
-    } v32;
-};
-
-struct Score {
+/// Score enum keeps a midgame and an endgame value in a single
+/// integer (enum), first LSB 16 bits are used to store endgame
+/// value, while upper bits are used for midgame value.
 
-    Score() {}
-    Score(const Score& s) { v = s.v; }
-    Score(int mg, int eg) { v.v32.mgv = int32_t(mg); v.v32.egv = int32_t(eg); }
+enum Score { ENSURE_32_BIT_SIZE = 1 << 31 };
 
-    Score& operator=(const Score& s) { v = s.v; return *this; }
-    Score& operator+=(const Score& s) { v.v32.mgv += s.v.v32.mgv; v.v32.egv += s.v.v32.egv; return *this; }
-    Score& operator-=(const Score& s) { v.v32.mgv -= s.v.v32.mgv; v.v32.egv -= s.v.v32.egv; return *this; }
+inline Value eg_value(Score s) { return Value(int16_t(s & 0xffff)); }
+inline Value mg_value(Score s) { return Value((int(s) + 32768) >> 16); }
 
-    bool operator==(const Score& s) { return v.v64 == s.v.v64; }
-    bool operator!=(const Score& s) { return v.v64 != s.v.v64; }
+inline Score make_score(int mg, int eg) { return Score((mg << 16) + eg); }
 
-    Value mg() const { return Value(v.v32.mgv); }
-    Value eg() const { return Value(v.v32.egv); }
+inline Score operator-(Score s) { return Score(-int(s)); }
+inline Score operator+(Score s1, Score s2) { return Score(int(s1) + int(s2)); }
+inline Score operator-(Score s1, Score s2) { return Score(int(s1) - int(s2)); }
+inline void operator+=(Score& s1, Score s2) { s1 = Score(int(s1) + int(s2)); }
+inline void operator-=(Score& s1, Score s2) { s1 = Score(int(s1) - int(s2)); }
+inline Score operator*(int i, Score s) { return Score(i * int(s)); }
 
-private:
-    ScoreValue v;
-};
+// Division must be handled separately for each term
+inline Score operator/(Score s, int i) { return make_score(mg_value(s) / i, eg_value(s) / i); }
 
-inline Score operator+(Score s1, Score s2) { return Score(s1.mg() + s2.mg(), s1.eg() + s2.eg()); }
-inline Score operator-(Score s1, Score s2) { return Score(s1.mg() - s2.mg(), s1.eg() - s2.eg()); }
-inline Score operator*(Score s1, Score s2) { return Score(s1.mg() * s2.mg(), s1.eg() * s2.eg()); }
-inline Score operator*(int i, Score s) { return Score(i * s.mg(), i * s.eg()); }
-inline Score operator*(Score s, int i) { return Score(s.mg() * i, s.eg() * i); }
-inline Score operator/(Score s, int i) { return Score(s.mg() / i, s.eg() / i); }
-inline Score operator-(Score s) { return Score(-s.mg(), -s.eg()); }
+// Only declared but not defined. We don't want to multiply two scores due to
+// a very high risk of overflow. So user should explicitly convert to integer.
+inline Score operator*(Score s1, Score s2);
 
-extern std::ostream& operator<<(std::ostream& os, Score s);
 
 ////
 //// Constants and variables
@@ -138,7 +123,7 @@ const Value PieceValueEndgame[17] = {
 
 /// Bonus for having the side to move (modified by Joona Kiiski)
 
-const Score TempoValue = Score(48, 22);
+const Score TempoValue = make_score(48, 22);
 
 
 ////