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made fast_modulo universally available in 64 bits and never used in 32 bits

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This commit is contained in:
joaquintides
2022-06-26 19:13:54 +02:00
parent 2670bb149d
commit fb733483c6
2 changed files with 26 additions and 78 deletions
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45
include/boost/unordered/detail/fca.hpp
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@@ -148,10 +148,6 @@ namespace boost {
#if ((((UINTPTR_MAX >> 16) >> 16) >> 16) >> 15) != 0
#define BOOST_UNORDERED_FCA_HAS_64B_SIZE_T
#endif
#endif
#if !defined(BOOST_NO_INT64_T)
#define BOOST_UNORDERED_FCA_FASTMOD_SUPPORT
#endif
template <class = void> struct prime_fmod_size
@@ -166,10 +162,10 @@ namespace boost {
static std::size_t const sizes_len;
static std::size_t (*positions[])(std::size_t);
#if defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT)
#if defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T)
static uint64_t inv_sizes32[];
static std::size_t const inv_sizes32_len;
#endif /* defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT) */
#endif /* defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T) */
static inline std::size_t size_index(std::size_t n)
{
@@ -192,7 +188,7 @@ namespace boost {
return hash % Size;
}
#if defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT)
#if defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T)
// We emulate the techniques taken from:
// Faster Remainder by Direct Computation: Applications to Compilers and
// Software Libraries
@@ -204,14 +200,15 @@ namespace boost {
static inline uint64_t get_remainder(uint64_t fractional, uint32_t d)
{
#if defined(_MSC_VER) && defined(_WIN64)
// use MSVC instrinsic when available to avoid promotion to 128 bits
#if defined(_MSC_VER)
// use MSVC intrinsics when available to avoid promotion to 128 bits
return __umulh(fractional, d);
#elif defined(BOOST_HAS_INT128)
return static_cast<uint64_t>(((boost::uint128_type)fractional * d) >> 64);
#else
// portable implementation in the absence of boost::uint128_type
// portable implementation in the absence of boost::uint128_type on 64 bits,
// which happens at least in GCC 4.5 and prior
uint64_t r1 = (fractional & UINT32_MAX) * d;
uint64_t r2 = (fractional >> 32 ) * d;
@@ -225,12 +222,11 @@ namespace boost {
uint64_t fractional = M * a;
return (uint32_t)(get_remainder(fractional, d));
}
#endif /* defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT) */
#endif /* defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T) */
static inline std::size_t position(
std::size_t hash, std::size_t size_index)
{
#if defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT)
#if defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T)
std::size_t sizes_under_32bit = inv_sizes32_len;
if (BOOST_LIKELY(size_index < sizes_under_32bit)) {
@@ -239,13 +235,9 @@ namespace boost {
} else {
return positions[size_index - sizes_under_32bit](hash);
}
#else
return fast_modulo(
hash, inv_sizes32[size_index], uint32_t(sizes[size_index]));
#endif /* defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T) */
#else
return positions[size_index](hash);
#endif /* defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT) */
#endif /* defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T) */
}
}; // prime_fmod_size
@@ -313,7 +305,7 @@ namespace boost {
// Similarly here, we have to re-express the integer initialization using
// arithmetic such that each literal can fit in a 32-bit value.
//
#if defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT)
#if defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T)
// clang-format off
template <class T>
uint64_t prime_fmod_size<T>::inv_sizes32[] = {
@@ -346,34 +338,27 @@ namespace boost {
(boost::ulong_long_type(5ul) << 32) + boost::ulong_long_type(1431653234ul) /* = 22906489714 */,
(boost::ulong_long_type(2ul) << 32) + boost::ulong_long_type(2863311496ul) /* = 11453246088 */,
(boost::ulong_long_type(1ul) << 32) + boost::ulong_long_type(1431655764ul) /* = 5726623060 */,
#if defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T)
};
#else
(boost::ulong_long_type(1ul) << 32) + boost::ulong_long_type(6ul) /* 4294967302 */
};
// clang-format on
#endif /* !defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T) */
template <class T>
std::size_t const
prime_fmod_size<T>::inv_sizes32_len = sizeof(inv_sizes32) /
sizeof(inv_sizes32[0]);
#endif /* defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT) */
#endif /* defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T) */
#define BOOST_UNORDERED_PRIME_FMOD_POSITIONS_ELEMENT(z, _, n) \
prime_fmod_size<T>::template modulo<n>,
template <class T>
std::size_t (*prime_fmod_size<T>::positions[])(std::size_t) = {
#if !defined(BOOST_UNORDERED_FCA_FASTMOD_SUPPORT)
#if !defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T)
BOOST_PP_SEQ_FOR_EACH(BOOST_UNORDERED_PRIME_FMOD_POSITIONS_ELEMENT, ~,
BOOST_UNORDERED_PRIME_FMOD_SIZES_32BIT)
#endif
#if defined(BOOST_UNORDERED_FCA_HAS_64B_SIZE_T)
BOOST_PP_SEQ_FOR_EACH(BOOST_UNORDERED_PRIME_FMOD_POSITIONS_ELEMENT, ~,
BOOST_UNORDERED_PRIME_FMOD_SIZES_64BIT)
#else
BOOST_PP_SEQ_FOR_EACH(BOOST_UNORDERED_PRIME_FMOD_POSITIONS_ELEMENT, ~,
BOOST_UNORDERED_PRIME_FMOD_SIZES_64BIT)
#endif
};