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fix ctz/clz bitwise operation implementation

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This commit is contained in:
bolero-MURAKAMI 2014-04-13 17:48:24 +09:00
parent fb69a146dd
commit 3e4dd5de00
3 changed files with 125 additions and 39 deletions
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4
sprout/bit/clrsb.hpp
View file

@ -30,7 +30,7 @@ namespace sprout {
# endif # endif
template<typename Integral> template<typename Integral>
inline SPROUT_CONSTEXPR int inline SPROUT_CONSTEXPR int
clrsb(Integral x) { clrsb(Integral x) SPROUT_NOEXCEPT {
return sprout::clz(~x); return sprout::clz(~x);
} }
} // namespace detail } // namespace detail
@ -42,7 +42,7 @@ namespace sprout {
std::is_integral<Integral>::value, std::is_integral<Integral>::value,
int int
>::type >::type
clrsb(Integral x) { clrsb(Integral x) SPROUT_NOEXCEPT {
return sprout::detail::clrsb(x); return sprout::detail::clrsb(x);
} }
} // namespace sprout } // namespace sprout

83
sprout/bit/clz.hpp
View file

@ -11,6 +11,9 @@
#include <climits> #include <climits>
#include <type_traits> #include <type_traits>
#include <sprout/config.hpp> #include <sprout/config.hpp>
#include <sprout/utility/pair/pair.hpp>
#include <sprout/bit/shlr.hpp>
#include <sprout/bit/shll.hpp>
namespace sprout { namespace sprout {
namespace detail { namespace detail {
@ -28,32 +31,68 @@ namespace sprout {
return __builtin_clzll(x); return __builtin_clzll(x);
} }
# endif # endif
template<typename Integral> template<std::size_t N, typename Integral>
inline SPROUT_CONSTEXPR int inline SPROUT_CONSTEXPR typename std::enable_if<
clz_non0_impl(Integral x, Integral m = Integral(1) << (CHAR_BIT * sizeof(Integral) - 1)) { (N == 1),
return m == 0 || x & m ? 0 sprout::pair<Integral, int>
: 1 + sprout::detail::clz_non0_impl(x, static_cast<Integral>(m >> 1)) >::type
; clz_bytes(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
return xn;
}
template<std::size_t N, typename Integral>
inline SPROUT_CONSTEXPR typename std::enable_if<
(N > 1),
sprout::pair<Integral, int>
>::type
clz_bytes(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::clz_bytes<N / 2>(
sprout::shlr(xn.first, (sizeof(Integral) - N / 2) * CHAR_BIT) ? xn
: type(sprout::shll(xn.first, N / 2 * CHAR_BIT), xn.second + N / 2 * CHAR_BIT)
);
} }
template<typename Integral> template<typename Integral>
inline SPROUT_CONSTEXPR typename std::enable_if< inline SPROUT_CONSTEXPR sprout::pair<Integral, int>
std::is_unsigned<Integral>::value, clz_bytes(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
int return sprout::detail::clz_bytes<sizeof(Integral)>(xn);
>::type
clz_non0(Integral x) {
return sprout::detail::clz_non0_impl(static_cast<Integral>(x));
}
template<typename Integral>
inline SPROUT_CONSTEXPR typename std::enable_if<
std::is_signed<Integral>::value,
int
>::type
clz_non0(Integral x) {
return sprout::detail::clz_non0(static_cast<typename std::make_unsigned<Integral>::type>(x));
} }
template<typename Integral> template<typename Integral>
inline SPROUT_CONSTEXPR int inline SPROUT_CONSTEXPR int
clz(Integral x) { clz_bits1(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
return xn.second - sprout::shlr(xn.first, sizeof(Integral) * CHAR_BIT - 1);
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
clz_bits2(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::clz_bits1(
sprout::shlr(xn.first, sizeof(Integral) * CHAR_BIT - 2) ? xn
: type(sprout::shll(xn.first, 2), xn.second + 2)
);
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
clz_bits4(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::clz_bits2(
sprout::shlr(xn.first, sizeof(Integral) * CHAR_BIT - 4) ? xn
: type(sprout::shll(xn.first, 4), xn.second + 4)
);
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
clz_bits(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
return sprout::detail::clz_bits4(xn);
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
clz_non0(Integral x) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::clz_bits(sprout::detail::clz_bytes(type(x, 1)));
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
clz(Integral x) SPROUT_NOEXCEPT {
return x == 0 ? static_cast<int>(sizeof(x) * CHAR_BIT) return x == 0 ? static_cast<int>(sizeof(x) * CHAR_BIT)
: sprout::detail::clz_non0(x) : sprout::detail::clz_non0(x)
; ;
@ -67,7 +106,7 @@ namespace sprout {
std::is_integral<Integral>::value, std::is_integral<Integral>::value,
int int
>::type >::type
clz(Integral x) { clz(Integral x) SPROUT_NOEXCEPT {
return sprout::detail::clz(x); return sprout::detail::clz(x);
} }
} // namespace sprout } // namespace sprout

77
sprout/bit/ctz.hpp
View file

@ -11,6 +11,10 @@
#include <climits> #include <climits>
#include <type_traits> #include <type_traits>
#include <sprout/config.hpp> #include <sprout/config.hpp>
#include <sprout/limits.hpp>
#include <sprout/detail/integer.hpp>
#include <sprout/utility/pair/pair.hpp>
#include <sprout/bit/shlr.hpp>
namespace sprout { namespace sprout {
namespace detail { namespace detail {
@ -28,27 +32,70 @@ namespace sprout {
return __builtin_ctzll(x); return __builtin_ctzll(x);
} }
# endif # endif
template<typename Integral> template<std::size_t N, typename Integral>
inline SPROUT_CONSTEXPR typename std::enable_if< inline SPROUT_CONSTEXPR typename std::enable_if<
std::is_unsigned<Integral>::value, (N == 1),
int sprout::pair<Integral, int>
>::type >::type
ctz_non0(Integral x) { ctz_bytes(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
return x & 1 ? 0 return xn;
: 1 + sprout::detail::ctz_non0(static_cast<Integral>(x >> 1)) }
; template<std::size_t N, typename Integral>
inline SPROUT_CONSTEXPR typename std::enable_if<
(N > 1),
sprout::pair<Integral, int>
>::type
ctz_bytes(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::ctz_bytes<N / 2>(
(xn.first & static_cast<Integral>(sprout::numeric_limits<typename sprout::detail::uint_t<N / 2 * CHAR_BIT>::least>::max())) ? xn
: type(sprout::shlr(xn.first, N / 2 * CHAR_BIT), xn.second + N / 2 * CHAR_BIT)
);
} }
template<typename Integral> template<typename Integral>
inline SPROUT_CONSTEXPR typename std::enable_if< inline SPROUT_CONSTEXPR sprout::pair<Integral, int>
std::is_signed<Integral>::value, ctz_bytes(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
int return sprout::detail::ctz_bytes<sizeof(Integral)>(xn);
>::type
ctz_non0(Integral x) {
return sprout::detail::ctz_non0(static_cast<typename std::make_unsigned<Integral>::type>(x));
} }
template<typename Integral> template<typename Integral>
inline SPROUT_CONSTEXPR int inline SPROUT_CONSTEXPR int
ctz(Integral x) { ctz_bits1(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
return (xn.first & Integral(0x1ul)) ? xn.second
: xn.second + 1
;
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
ctz_bits2(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::ctz_bits1(
(xn.first & Integral(0x3ul)) ? xn
: type(sprout::shlr(xn.first, 2), xn.second + 2)
);
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
ctz_bits4(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::ctz_bits2(
(xn.first & Integral(0xful)) ? xn
: type(sprout::shlr(xn.first, 4), xn.second + 4)
);
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
ctz_bits(sprout::pair<Integral, int> const& xn) SPROUT_NOEXCEPT {
return sprout::detail::ctz_bits4(xn);
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
ctz_non0(Integral x) SPROUT_NOEXCEPT {
typedef sprout::pair<Integral, int> type;
return sprout::detail::ctz_bits(sprout::detail::ctz_bytes(type(x, 0)));
}
template<typename Integral>
inline SPROUT_CONSTEXPR int
ctz(Integral x) SPROUT_NOEXCEPT {
return x == 0 ? static_cast<int>(sizeof(x) * CHAR_BIT) return x == 0 ? static_cast<int>(sizeof(x) * CHAR_BIT)
: sprout::detail::ctz_non0(x) : sprout::detail::ctz_non0(x)
; ;
@ -62,7 +109,7 @@ namespace sprout {
std::is_integral<Integral>::value, std::is_integral<Integral>::value,
int int
>::type >::type
ctz(Integral x) { ctz(Integral x) SPROUT_NOEXCEPT {
return sprout::detail::ctz(x); return sprout::detail::ctz(x);
} }
} // namespace sprout } // namespace sprout