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Retire bitcount

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root 2015-01-10 13:25:38 +00:00
parent 0dca235bb1
commit 80d2d47f7d
2 changed files with 0 additions and 85 deletions
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1
src/bitboard.cpp
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@ -2,7 +2,6 @@
#include <cstring> // For std::memset
#include "bitboard.h"
#include "bitcount.h"
//#include "misc.h"
Bitboard FileBB[FILE_NB];

84
src/bitcount.h
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@ -1,84 +0,0 @@
#ifndef BITCOUNT_H_INCLUDED
#define BITCOUNT_H_INCLUDED
#include <cassert>
#include "types.h"
enum BitCountType {
CNT_64,
CNT_64_MAX15,
CNT_32,
CNT_32_MAX15,
CNT_HW_POPCNT
};
/// 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 non-zero bits in a bitboard
template<BitCountType> inline int popcount(Bitboard);
template<>
inline int popcount<CNT_64>(Bitboard b) {
b -= (b >> 1) & 0x5555555555555555ULL;
b = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
b = ((b >> 4) + b) & 0x0F0F0F0F0F0F0F0FULL;
return (b * 0x0101010101010101ULL) >> 56;
}
template<>
inline int popcount<CNT_64_MAX15>(Bitboard b) {
b -= (b >> 1) & 0x5555555555555555ULL;
b = ((b >> 2) & 0x3333333333333333ULL) + (b & 0x3333333333333333ULL);
return (b * 0x1111111111111111ULL) >> 60;
}
template<>
inline int popcount<CNT_32>(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
w -= (w >> 1) & 0x55555555;
v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
v = ((v >> 4) + v + (w >> 4) + w) & 0x0F0F0F0F;
return (v * 0x01010101) >> 24;
}
template<>
inline int popcount<CNT_32_MAX15>(Bitboard b) {
unsigned w = unsigned(b >> 32), v = unsigned(b);
v -= (v >> 1) & 0x55555555; // 0-2 in 2 bits
w -= (w >> 1) & 0x55555555;
v = ((v >> 2) & 0x33333333) + (v & 0x33333333); // 0-4 in 4 bits
w = ((w >> 2) & 0x33333333) + (w & 0x33333333);
return ((v + w) * 0x11111111) >> 28;
}
template<>
inline int popcount<CNT_HW_POPCNT>(Bitboard b) {
#ifndef USE_POPCNT
assert(false);
return b != 0; // Avoid 'b not used' warning
#elif defined(_MSC_VER) && defined(__INTEL_COMPILER)
return _mm_popcnt_u64(b);
#elif defined(_MSC_VER)
return (int)__popcnt64(b);
#else
return __builtin_popcountll(b);
#endif
}
#endif // #ifndef BITCOUNT_H_INCLUDED