X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitboard.cpp;h=04b46e5d3603f8275ad3643c4385ceab0d286074;hp=18b7bb28206d5db0d0a23c026b2caf12558fc466;hb=91f0c0878962f80ca27d78da9a096b52a5aec684;hpb=b3b1d3aaa7e0fa3cd28f8d9d2d5b1dd562b914c3

diff --git a/src/bitboard.cpp b/src/bitboard.cpp
index 18b7bb28..04b46e5d 100644
--- a/src/bitboard.cpp
+++ b/src/bitboard.cpp
@@ -233,6 +233,8 @@ Bitboard BishopPseudoAttacks[64];
 Bitboard RookPseudoAttacks[64];
 Bitboard QueenPseudoAttacks[64];
 
+uint8_t BitCount8Bit[256];
+
 
 ////
 //// Local definitions
@@ -295,6 +297,7 @@ void init_bitboards() {
 
 #if defined(IS_64BIT) && !defined(USE_BSFQ)
 
+CACHE_LINE_ALIGNMENT
 static const int BitTable[64] = {
   0, 1, 2, 7, 3, 13, 8, 19, 4, 25, 14, 28, 9, 34, 20, 40, 5, 17, 26, 38, 15,
   46, 29, 48, 10, 31, 35, 54, 21, 50, 41, 57, 63, 6, 12, 18, 24, 27, 33, 39,
@@ -314,6 +317,7 @@ Square pop_1st_bit(Bitboard* b) {
 
 #elif !defined(USE_BSFQ)
 
+CACHE_LINE_ALIGNMENT
 static const int BitTable[64] = {
   63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
   51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
@@ -341,23 +345,17 @@ union b_union {
 Square pop_1st_bit(Bitboard* bb) {
 
   b_union u;
-  uint32_t b;
 
   u.b = *bb;
 
   if (u.dw.l)
   {
-      b = u.dw.l;
-      *((uint32_t*)bb) = b & (b - 1);
-      b ^= (b - 1);
-  }
-  else
-  {
-      b = u.dw.h;
-      *((uint32_t*)bb+1) = b & (b - 1); // Little endian only?
-      b = ~(b ^ (b - 1));
+      *((uint32_t*)bb) = u.dw.l & (u.dw.l - 1);
+      return Square(BitTable[((u.dw.l ^ (u.dw.l - 1)) * 0x783a9b23) >> 26]);
   }
-  return Square(BitTable[(b * 0x783a9b23) >> 26]);
+
+  *((uint32_t*)bb+1) = u.dw.h & (u.dw.h - 1); // Little endian only?
+  return Square(BitTable[((~(u.dw.h ^ (u.dw.h - 1))) * 0x783a9b23) >> 26]);
 }
 
 #endif
@@ -382,6 +380,9 @@ namespace {
           in_front_bb(c, s) & this_and_neighboring_files_bb(s);
         OutpostMask[c][s] = in_front_bb(c, s) & neighboring_files_bb(s);
       }
+
+    for (Bitboard b = 0ULL; b < 256ULL; b++)
+        BitCount8Bit[b] = (uint8_t)count_1s(b);
   }