libcxx/include/experimental/__simd/simd_mask.h

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_EXPERIMENTAL___SIMD_SIMD_MASK_H
#define _LIBCPP_EXPERIMENTAL___SIMD_SIMD_MASK_H

#include <__config>
#include <__cstddef/size_t.h>
#include <__type_traits/enable_if.h>
#include <__type_traits/is_same.h>
#include <experimental/__simd/declaration.h>
#include <experimental/__simd/reference.h>
#include <experimental/__simd/traits.h>

#if _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)

_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL
inline namespace parallelism_v2 {

// class template simd_mask [simd.mask.class]
// TODO: implement simd_mask class
template <class _Tp, class _Abi>
class simd_mask {
  using _Impl _LIBCPP_NODEBUG    = __mask_operations<_Tp, _Abi>;
  using _Storage _LIBCPP_NODEBUG = typename _Impl::_MaskStorage;

  _Storage __s_;

public:
  using value_type = bool;
  using reference  = __simd_reference<_Tp, _Storage, value_type>;
  using simd_type  = simd<_Tp, _Abi>;
  using abi_type   = _Abi;

  static _LIBCPP_HIDE_FROM_ABI constexpr size_t size() noexcept { return simd_type::size(); }

  _LIBCPP_HIDE_FROM_ABI simd_mask() noexcept = default;

  // explicit conversion from and to implementation-defined types
  struct __storage_tag_t {};
  static constexpr __storage_tag_t __storage_tag{};
  explicit _LIBCPP_HIDE_FROM_ABI operator _Storage() const { return __s_; }
  explicit _LIBCPP_HIDE_FROM_ABI simd_mask(const _Storage& __s, __storage_tag_t) : __s_(__s) {}

  // broadcast constructor
  _LIBCPP_HIDE_FROM_ABI explicit simd_mask(value_type __v) noexcept : __s_(_Impl::__broadcast(__v)) {}

  // implicit type conversion constructor
  template <class _Up, enable_if_t<!is_same_v<_Up, _Tp> && is_same_v<abi_type, simd_abi::fixed_size<size()>>, int> = 0>
  _LIBCPP_HIDE_FROM_ABI simd_mask(const simd_mask<_Up, simd_abi::fixed_size<size()>>& __v) noexcept {
    for (size_t __i = 0; __i < size(); __i++) {
      (*this)[__i] = __v[__i];
    }
  }

  // load constructor
  template <class _Flags, enable_if_t<is_simd_flag_type_v<_Flags>, int> = 0>
  _LIBCPP_HIDE_FROM_ABI simd_mask(const value_type* __mem, _Flags) {
    _Impl::__load(__s_, _Flags::template __apply<simd_mask>(__mem));
  }

  // copy functions
  template <class _Flags, enable_if_t<is_simd_flag_type_v<_Flags>, int> = 0>
  _LIBCPP_HIDE_FROM_ABI void copy_from(const value_type* __mem, _Flags) {
    _Impl::__load(__s_, _Flags::template __apply<simd_mask>(__mem));
  }

  template <class _Flags, enable_if_t<is_simd_flag_type_v<_Flags>, int> = 0>
  _LIBCPP_HIDE_FROM_ABI void copy_to(value_type* __mem, _Flags) const {
    _Impl::__store(__s_, _Flags::template __apply<simd_mask>(__mem));
  }

  // scalar access [simd.mask.subscr]
  _LIBCPP_HIDE_FROM_ABI reference operator[](size_t __i) noexcept { return reference(__s_, __i); }
  _LIBCPP_HIDE_FROM_ABI value_type operator[](size_t __i) const noexcept { return __s_.__get(__i); }
};

template <class _Tp, class _Abi>
inline constexpr bool is_simd_mask_v<simd_mask<_Tp, _Abi>> = true;

template <class _Tp>
using native_simd_mask = simd_mask<_Tp, simd_abi::native<_Tp>>;

template <class _Tp, int _Np>
using fixed_size_simd_mask = simd_mask<_Tp, simd_abi::fixed_size<_Np>>;

} // namespace parallelism_v2
_LIBCPP_END_NAMESPACE_EXPERIMENTAL

#endif // _LIBCPP_STD_VER >= 17 && defined(_LIBCPP_ENABLE_EXPERIMENTAL)
#endif // _LIBCPP_EXPERIMENTAL___SIMD_SIMD_MASK_H