Retire MovePicker::see_sign()

[stockfish] / src / bitboard.cpp

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index ba1af2f2865f28865791178206add9752a392889..318ce049954f7d03316c532c5dba1db3703554e5 100644 (file)
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -21,9 +21,9 @@
 #include <algorithm>
 
 #include "bitboard.h"
-#include "bitcount.h"
 #include "misc.h"
 
+uint8_t PopCnt16[1 << 16];
 int SquareDistance[SQUARE_NB][SQUARE_NB];
 
 Bitboard  RookMasks  [SQUARE_NB];
@@ -74,6 +74,16 @@ namespace {
     return Is64Bit ? (b * DeBruijn64) >> 58
                    : ((unsigned(b) ^ unsigned(b >> 32)) * DeBruijn32) >> 26;
   }
+
+
+  // popcount16() counts the non-zero bits using SWAR-Popcount algorithm
+
+  unsigned popcount16(unsigned u) {
+    u -= (u >> 1) & 0x5555U;
+    u = ((u >> 2) & 0x3333U) + (u & 0x3333U);
+    u = ((u >> 4) + u) & 0x0F0FU;
+    return (u * 0x0101U) >> 8;
+  }
 }
 
 #ifdef NO_BSF
@@ -141,6 +151,9 @@ const std::string Bitboards::pretty(Bitboard b) {
 
 void Bitboards::init() {
 
+  for (unsigned i = 0; i < (1 << 16); ++i)
+      PopCnt16[i] = (uint8_t) popcount16(i);
+
   for (Square s = SQ_A1; s <= SQ_H8; ++s)
   {
       SquareBB[s] = 1ULL << s;
@@ -265,7 +278,7 @@ namespace {
         // the number of 1s of the mask. Hence we deduce the size of the shift to
         // apply to the 64 or 32 bits word to get the index.
         masks[s]  = sliding_attack(deltas, s, 0) & ~edges;
-        shifts[s] = (Is64Bit ? 64 : 32) - popcount<Max15>(masks[s]);
+        shifts[s] = (Is64Bit ? 64 : 32) - popcount(masks[s]);
 
         // Use Carry-Rippler trick to enumerate all subsets of masks[s] and
         // store the corresponding sliding attack bitboard in reference[].
@@ -296,7 +309,7 @@ namespace {
         do {
             do
                 magics[s] = rng.sparse_rand<Bitboard>();
-            while (popcount<Max15>((magics[s] * masks[s]) >> 56) < 6);
+            while (popcount((magics[s] * masks[s]) >> 56) < 6);
 
             // A good magic must map every possible occupancy to an index that
             // looks up the correct sliding attack in the attacks[s] database.