X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fbitcount.h;h=9d25a5e5c1b4d7b7bd19c0bd0cd60234209741a5;hb=51e8efdab5f62ebc23e4f7adaea96f619cbca194;hp=3c5ba2a1fa4004e40905e0b2514d76d4ab1518ee;hpb=7614501362896ddee902c1257f1b56ad148bc4d3;p=stockfish
diff --git a/src/bitcount.h b/src/bitcount.h
index 3c5ba2a1..9d25a5e5 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) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2012 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
@@ -18,29 +18,32 @@
along with this program. If not, see .
*/
-
#if !defined(BITCOUNT_H_INCLUDED)
#define BITCOUNT_H_INCLUDED
+#include
#include "types.h"
enum BitCountType {
- CNT64,
- CNT64_MAX15,
- CNT32,
- CNT32_MAX15,
- CNT_POPCNT
+ CNT_64,
+ CNT_64_MAX15,
+ CNT_32,
+ CNT_32_MAX15,
+ CNT_HW_POPCNT
};
-/// count_1s() counts the number of nonzero bits in a bitboard.
-/// We have different optimized versions according if platform
-/// is 32 or 64 bits, and to the maximum number of nonzero bits.
-/// We also support hardware popcnt instruction. See Readme.txt
-/// on how to pgo compile with popcnt support.
-template inline int count_1s(Bitboard);
+/// 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 or
+/// use hardware popcnt instruction when 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
+template inline int popcount(Bitboard);
template<>
-inline int count_1s(Bitboard b) {
+inline int popcount(Bitboard b) {
b -= ((b>>1) & 0x5555555555555555ULL);
b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
b = ((b>>4) + b) & 0x0F0F0F0F0F0F0F0FULL;
@@ -49,7 +52,7 @@ inline int count_1s(Bitboard b) {
}
template<>
-inline int count_1s(Bitboard b) {
+inline int popcount(Bitboard b) {
b -= (b>>1) & 0x5555555555555555ULL;
b = ((b>>2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
b *= 0x1111111111111111ULL;
@@ -57,7 +60,7 @@ inline int count_1s(Bitboard b) {
}
template<>
-inline int count_1s(Bitboard b) {
+inline int popcount(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
w -= (w >> 1) & 0x55555555;
@@ -70,7 +73,7 @@ inline int count_1s(Bitboard b) {
}
template<>
-inline int count_1s(Bitboard b) {
+inline int popcount(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
w -= (w >> 1) & 0x55555555;
@@ -82,46 +85,28 @@ inline int count_1s(Bitboard b) {
}
template<>
-inline int count_1s(Bitboard b) {
+inline int popcount(Bitboard b) {
+
#if !defined(USE_POPCNT)
+
+ assert(false);
return int(b != 0); // Avoid 'b not used' warning
-#elif defined(_MSC_VER) && defined(__INTEL_COMPILER)
- return _mm_popcnt_u64(b);
-#elif defined(_MSC_VER)
- return __popcnt64(b);
-#elif defined(__GNUC__)
- unsigned long ret;
- __asm__("popcnt %1, %0" : "=r" (ret) : "r" (b));
- return ret;
-#endif
-}
+#elif defined(_MSC_VER) && defined(__INTEL_COMPILER)
-/// cpu_has_popcnt() detects support for popcnt instruction at runtime
-inline bool cpu_has_popcnt() {
+ return _mm_popcnt_u64(b);
- int CPUInfo[4] = {-1};
- __cpuid(CPUInfo, 0x00000001);
- return (CPUInfo[2] >> 23) & 1;
-}
+#elif defined(_MSC_VER)
+ return (int)__popcnt64(b);
-/// CpuHasPOPCNT is a global constant initialized at startup that
-/// is set to true if CPU on which application runs supports popcnt
-/// hardware instruction. Unless USE_POPCNT is not defined.
-#if defined(USE_POPCNT)
-const bool CpuHasPOPCNT = cpu_has_popcnt();
#else
-const bool CpuHasPOPCNT = false;
-#endif
+ unsigned long ret;
+ __asm__("popcnt %1, %0" : "=r" (ret) : "r" (b));
+ return ret;
-/// CpuIs64Bit is a global constant initialized at compile time that
-/// is set to true if CPU on which application runs is a 64 bits.
-#if defined(IS_64BIT)
-const bool CpuIs64Bit = true;
-#else
-const bool CpuIs64Bit = false;
#endif
+}
#endif // !defined(BITCOUNT_H_INCLUDED)