X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fbitcount.h;h=63d7704b91edbb85643def092c194eeb468151bc;hp=a2e6c5be30eb5d80fc074b90bcbde4d5de35c124;hb=66b751713e1785cc4ae1779318ae2fdafa734add;hpb=92b625d04f0d240a80defbfb2c95178a835efc6e

diff --git a/src/bitcount.h b/src/bitcount.h
index a2e6c5be..63d7704b 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) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 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
@@ -22,62 +22,22 @@
 #if !defined(BITCOUNT_H_INCLUDED)
 #define BITCOUNT_H_INCLUDED
 
-// To enable POPCNT support uncomment USE_POPCNT define. For PGO compile on a Core i7
-// you may want to collect profile data first with USE_POPCNT disabled and then, in a
-// second profiling session, with USE_POPCNT enabled so to exercise both paths. Don't
-// forget to leave USE_POPCNT enabled for the final optimized compile though ;-)
-
-//#define USE_POPCNT
-
-
 #include "types.h"
 
-// Select type of intrinsic bit count instruction to use
-
-#if defined(__INTEL_COMPILER) && defined(IS_64BIT) && defined(USE_POPCNT) // Intel compiler
-
-#include <nmmintrin.h>
-
-inline bool cpu_has_popcnt() {
-
-  int CPUInfo[4] = {-1};
-  __cpuid(CPUInfo, 0x00000001);
-  return (CPUInfo[2] >> 23) & 1;
-}
-
-// Define a dummy template to workaround a compile error if _mm_popcnt_u64() is not defined.
-//
-// If _mm_popcnt_u64() is defined in <nmmintrin.h> it will be choosen first due to
-// C++ overload rules that always prefer a function to a template with the same name.
-// If not, we avoid a compile error and because cpu_has_popcnt() should return false,
-// our templetized _mm_popcnt_u64() is never called anyway.
-template<typename T> unsigned _mm_popcnt_u64(T) { return 0; } // Is never called
-
-#define POPCNT_INTRINSIC(x) _mm_popcnt_u64(x)
-
-#elif defined(_MSC_VER) && defined(IS_64BIT) && defined(USE_POPCNT) // Microsoft compiler
-
-#include <intrin.h>
-
-inline bool cpu_has_popcnt() {
-
-  int CPUInfo[4] = {-1};
-  __cpuid(CPUInfo, 0x00000001);
-  return (CPUInfo[2] >> 23) & 1;
-}
-
-// See comment of _mm_popcnt_u64<>() few lines above for an explanation.
-template<typename T> unsigned __popcnt64(T) { return 0; } // Is never called
-
-#define POPCNT_INTRINSIC(x) __popcnt64(x)
-
-#else // Safe fallback for unsupported compilers or when USE_POPCNT is disabled
-
-inline bool cpu_has_popcnt() { return false; }
-
+// Select type of intrinsic bit count instruction to use, see
+// README.txt on how to pgo compile with POPCNT support.
+#if !defined(USE_POPCNT)
 #define POPCNT_INTRINSIC(x) 0
+#elif defined(_MSC_VER)
+#define POPCNT_INTRINSIC(x) (int)__popcnt64(x)
+#elif defined(__GNUC__)
 
-#endif // cpu_has_popcnt() and POPCNT_INTRINSIC() definitions
+#define POPCNT_INTRINSIC(x) ({ \
+   unsigned long __ret; \
+   __asm__("popcnt %1, %0" : "=r" (__ret) : "r" (x)); \
+   __ret; })
+
+#endif
 
 
 /// Software implementation of bit count functions
@@ -144,10 +104,23 @@ inline int count_1s_max_15(Bitboard b) {
 }
 
 
+// Detect hardware POPCNT support
+inline bool cpu_has_popcnt() {
+
+  int CPUInfo[4] = {-1};
+  __cpuid(CPUInfo, 0x00000001);
+  return (CPUInfo[2] >> 23) & 1;
+}
+
+
 // Global constant initialized at startup that is set to true if
 // CPU on which application runs supports POPCNT intrinsic. Unless
 // USE_POPCNT is not defined.
+#if defined(USE_POPCNT)
 const bool CpuHasPOPCNT = cpu_has_popcnt();
+#else
+const bool CpuHasPOPCNT = false;
+#endif
 
 
 // Global constant used to print info about the use of 64 optimized