1// -*- C++ -*-
  2//===----------------------------------------------------------------------===//
  3//
  4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  5// See https://llvm.org/LICENSE.txt for license information.
  6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  7//
  8//===----------------------------------------------------------------------===//
  9
 10#ifndef _LIBCPP_EXPERIMENTAL___SIMD_UTILITY_H
 11#define _LIBCPP_EXPERIMENTAL___SIMD_UTILITY_H
 12
 13#include <__config>
 14#include <__cstddef/size_t.h>
 15#include <__type_traits/is_arithmetic.h>
 16#include <__type_traits/is_const.h>
 17#include <__type_traits/is_constant_evaluated.h>
 18#include <__type_traits/is_convertible.h>
 19#include <__type_traits/is_same.h>
 20#include <__type_traits/is_unsigned.h>
 21#include <__type_traits/is_volatile.h>
 22#include <__type_traits/void_t.h>
 23#include <__utility/declval.h>
 24#include <__utility/integer_sequence.h>
 25#include <cstdint>
 26#include <limits>
 27
 28_LIBCPP_PUSH_MACROS
 29#include <__undef_macros>
 30
 31#if _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)
 32
 33_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL
 34inline namespace parallelism_v2 {
 35template <class _Tp>
 36inline constexpr bool __is_vectorizable_v =
 37    is_arithmetic_v<_Tp> && !is_const_v<_Tp> && !is_volatile_v<_Tp> && !is_same_v<_Tp, bool>;
 38
 39template <class _Tp>
 40_LIBCPP_HIDE_FROM_ABI auto __choose_mask_type() {
 41  if constexpr (sizeof(_Tp) == 1) {
 42    return uint8_t{};
 43  } else if constexpr (sizeof(_Tp) == 2) {
 44    return uint16_t{};
 45  } else if constexpr (sizeof(_Tp) == 4) {
 46    return uint32_t{};
 47  } else if constexpr (sizeof(_Tp) == 8) {
 48    return uint64_t{};
 49  }
 50#  if _LIBCPP_HAS_INT128
 51  else if constexpr (sizeof(_Tp) == 16) {
 52    return __uint128_t{};
 53  }
 54#  endif
 55  else
 56    static_assert(sizeof(_Tp) == 0, "Unexpected size");
 57}
 58
 59template <class _Tp>
 60_LIBCPP_HIDE_FROM_ABI auto constexpr __set_all_bits(bool __v) {
 61  return __v ? (numeric_limits<decltype(experimental::__choose_mask_type<_Tp>())>::max()) : 0;
 62}
 63
 64template <class _From, class _To, class = void>
 65inline constexpr bool __is_non_narrowing_convertible_v = false;
 66
 67template <class _From, class _To>
 68inline constexpr bool __is_non_narrowing_convertible_v<_From, _To, std::void_t<decltype(_To{std::declval<_From>()})>> =
 69    true;
 70
 71template <class _Tp, class _Up>
 72inline constexpr bool __can_broadcast_v =
 73    (__is_vectorizable_v<_Up> && __is_non_narrowing_convertible_v<_Up, _Tp>) ||
 74    (!__is_vectorizable_v<_Up> && is_convertible_v<_Up, _Tp>) || is_same_v<_Up, int> ||
 75    (is_same_v<_Up, unsigned int> && is_unsigned_v<_Tp>);
 76
 77template <class _Tp, class _Generator, std::size_t _Idx, class = void>
 78inline constexpr bool __is_well_formed = false;
 79
 80template <class _Tp, class _Generator, std::size_t _Idx>
 81inline constexpr bool
 82    __is_well_formed<_Tp,
 83                     _Generator,
 84                     _Idx,
 85                     std::void_t<decltype(std::declval<_Generator>()(integral_constant<size_t, _Idx>()))>> =
 86        __can_broadcast_v<_Tp, decltype(std::declval<_Generator>()(integral_constant<size_t, _Idx>()))>;
 87
 88template <class _Tp, class _Generator, std::size_t... _Idxes>
 89_LIBCPP_HIDE_FROM_ABI constexpr bool __can_generate(index_sequence<_Idxes...>) {
 90  return (true && ... && __is_well_formed<_Tp, _Generator, _Idxes>);
 91}
 92
 93template <class _Tp, class _Generator, std::size_t _Size>
 94inline constexpr bool __can_generate_v = experimental::__can_generate<_Tp, _Generator>(make_index_sequence<_Size>());
 95
 96} // namespace parallelism_v2
 97_LIBCPP_END_NAMESPACE_EXPERIMENTAL
 98
 99#endif // _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)
100
101_LIBCPP_POP_MACROS
102
103#endif // _LIBCPP_EXPERIMENTAL___SIMD_UTILITY_H