X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitcount.h;h=8bc06177ddb84493d7ead7d12aaefdff4c6a9388;hp=ad8df94ab078522066fdfa44da80c931fa732c88;hb=cb2111f0b62afec5fd977e1dd4ca5843bd006956;hpb=002062ae934c1fae3e56157e8e7e6451b552ada5

diff --git a/src/bitcount.h b/src/bitcount.h
index ad8df94a..8bc06177 100644
--- a/src/bitcount.h
+++ b/src/bitcount.h
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -22,6 +22,7 @@
 #define BITCOUNT_H_INCLUDED
 
 #include <cassert>
+
 #include "types.h"
 
 enum BitCountType {
@@ -32,14 +33,14 @@ enum BitCountType {
   CNT_HW_POPCNT
 };
 
-/// Determine at compile time the best popcount<> specialization according if
-/// platform is 32 or 64 bits, to the maximum number of nonzero bits to count
-/// and if hardware popcnt instruction is available.
-const BitCountType Full  = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64 : CNT_32;
+/// Determine at compile time the best popcount<> specialization according to
+/// whether the platform is 32 or 64 bit, the maximum number of non-zero
+/// bits to count and if the hardware popcnt instruction is available.
+const BitCountType Full  = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64       : CNT_32;
 const BitCountType Max15 = HasPopCnt ? CNT_HW_POPCNT : Is64Bit ? CNT_64_MAX15 : CNT_32_MAX15;
 
 
-/// popcount() counts the number of nonzero bits in a bitboard
+/// popcount() counts the number of non-zero bits in a bitboard
 template<BitCountType> inline int popcount(Bitboard);
 
 template<>
@@ -94,10 +95,9 @@ inline int popcount<CNT_HW_POPCNT>(Bitboard b) {
 
   return (int)__popcnt64(b);
 
-#else
+#else // Assumed gcc or compatible compiler
 
-  __asm__("popcnt %1, %0" : "=r" (b) : "r" (b));
-  return b;
+  return __builtin_popcountll(b);
 
 #endif
 }