diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -789,6 +789,9 @@
   expected
   experimental/__config
   experimental/__memory
+  experimental/__simd/scalar.h
+  experimental/__simd/utility.h
+  experimental/__simd/vec_ext.h
   experimental/algorithm
   experimental/deque
   experimental/forward_list
diff --git a/libcxx/include/experimental/__simd/scalar.h b/libcxx/include/experimental/__simd/scalar.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/experimental/__simd/scalar.h
@@ -0,0 +1,25 @@
+// -*- 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_SCALAR_H
+#define _LIBCPP_EXPERIMENTAL___SIMD_SCALAR_H
+
+#include <cstddef>
+#include <experimental/__config>
+
+_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD_ABI
+
+struct __scalar {
+  static constexpr bool __is_abi_tag  = true;
+  static constexpr size_t __simd_size = 1;
+};
+
+_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD_ABI
+
+#endif // _LIBCPP_EXPERIMENTAL___SIMD_SCALAR_H
diff --git a/libcxx/include/experimental/__simd/utility.h b/libcxx/include/experimental/__simd/utility.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/experimental/__simd/utility.h
@@ -0,0 +1,77 @@
+// -*- 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_UTILITY_H
+#define _LIBCPP_EXPERIMENTAL___SIMD_UTILITY_H
+
+#include <cstdint>
+#include <experimental/__config>
+#include <tuple>
+
+_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD
+
+class _Bool {
+  const bool __v;
+
+public:
+  constexpr _Bool(bool __b) : __v(__b) {}
+  _Bool(int) = delete;
+  constexpr operator bool() const { return __v; }
+};
+
+template <class _To, class _From>
+constexpr decltype(_To{declval<_From>()}, true) __is_non_narrowing_convertible_impl(_From) {
+  return true;
+}
+
+template <class _To>
+constexpr bool __is_non_narrowing_convertible_impl(...) {
+  return false;
+}
+
+template <class _From, class _To>
+constexpr bool __is_non_narrowing_arithmetic_convertible() {
+  if constexpr (is_arithmetic_v<_To> && is_arithmetic_v<_From>)
+    return __is_non_narrowing_convertible_impl<_To>(_From{});
+  else
+    return false;
+}
+
+template <class _Tp, class... _Args>
+constexpr _Tp __variadic_sum(_Args... __args) {
+  return (static_cast<_Tp>(__args) + ...);
+}
+
+template <class _Tp>
+constexpr bool __is_vectorizable() {
+  return is_arithmetic_v<_Tp> && !is_const_v<_Tp> && !is_volatile_v<_Tp> && !is_same_v<_Tp, bool>;
+}
+
+template <class _Tp, class _Up>
+constexpr bool __can_broadcast() {
+  return (is_arithmetic_v<_Up> && __is_non_narrowing_arithmetic_convertible<_Up, _Tp>()) ||
+         (!is_arithmetic_v<_Up> && is_convertible_v<_Up, _Tp>) || is_same_v<remove_const_t<_Up>, int> ||
+         (is_same_v<remove_const_t<_Up>, unsigned int> && is_unsigned_v<_Tp>);
+}
+
+template <class _Tp, class _Generator, size_t... __indicies>
+constexpr decltype(forward_as_tuple(declval<_Generator>()(integral_constant<size_t, __indicies>())...), bool())
+__can_generate(index_sequence<__indicies...>) {
+  return !__variadic_sum<bool>(
+      !__can_broadcast<_Tp, decltype(declval<_Generator>()(integral_constant<size_t, __indicies>()))>()...);
+}
+
+template <class _Tp, class _Generator>
+bool __can_generate(...) {
+  return false;
+}
+
+_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD
+
+#endif // _LIBCPP_EXPERIMENTAL___SIMD_UTILITY_H
diff --git a/libcxx/include/experimental/__simd/vec_ext.h b/libcxx/include/experimental/__simd/vec_ext.h
new file mode 100644
--- /dev/null
+++ b/libcxx/include/experimental/__simd/vec_ext.h
@@ -0,0 +1,26 @@
+// -*- 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_VEC_EXT_H
+#define _LIBCPP_EXPERIMENTAL___SIMD_VEC_EXT_H
+
+#include <cstddef>
+#include <experimental/__config>
+
+_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD_ABI
+
+template <int _Np>
+struct __vec_ext {
+  static constexpr bool __is_abi_tag  = _Np > 0 && _Np <= 32;
+  static constexpr size_t __simd_size = _Np;
+};
+
+_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD_ABI
+
+#endif // _LIBCPP_EXPERIMENTAL___SIMD_VEC_EXT_H
diff --git a/libcxx/include/experimental/simd b/libcxx/include/experimental/simd
--- a/libcxx/include/experimental/simd
+++ b/libcxx/include/experimental/simd
@@ -10,641 +10,218 @@
 #ifndef _LIBCPP_EXPERIMENTAL_SIMD
 #define _LIBCPP_EXPERIMENTAL_SIMD
 
+#define __cpp_lib_experimental_parallel_simd 201803
+
 /*
     experimental/simd synopsis
 
 namespace std::experimental {
-
 inline namespace parallelism_v2 {
+  namespace simd_abi {
+    using scalar = see below;
+    template<int N> using fixed_size = see below;
+    template<class T> inline constexpr int max_fixed_size = implementation-defined;
+    template<class T> using compatible = implementation-defined;
+    template<class T> using native = implementation-defined;
+
+    template<class T, size_t N, class... Abis> struct deduce { using type = see below; };
+    template<class T, size_t N, class... Abis> using deduce_t =
+      typename deduce<T, N, Abis...>::type;
+  }
 
-namespace simd_abi {
-
-struct scalar {};
-template <int N> struct fixed_size {};
-template <typename T> inline constexpr int max_fixed_size = implementation-defined;
-template <typename T> using compatible = implementation-defined;
-template <typename T> using native = implementation-defined;
-
-} // simd_abi
-
-struct element_aligned_tag {};
-struct vector_aligned_tag {};
-template <size_t> struct overaligned_tag {};
-inline constexpr element_aligned_tag element_aligned{};
-inline constexpr vector_aligned_tag vector_aligned{};
-template <size_t N> inline constexpr overaligned_tag<N> overaligned{};
-
-// traits [simd.traits]
-template <class T> struct is_abi_tag;
-template <class T> inline constexpr bool is_abi_tag_v = is_abi_tag<T>::value;
-
-template <class T> struct is_simd;
-template <class T> inline constexpr bool is_simd_v = is_simd<T>::value;
-
-template <class T> struct is_simd_mask;
-template <class T> inline constexpr bool is_simd_mask_v = is_simd_mask<T>::value;
-
-template <class T> struct is_simd_flag_type;
-template <class T> inline constexpr bool is_simd_flag_type_v = is_simd_flag_type<T>::value;
-
-template <class T, size_t N> struct abi_for_size { using type = see below; };
-template <class T, size_t N> using abi_for_size_t = typename abi_for_size<T, N>::type;
-
-template <class T, class Abi = simd_abi::compatible<T>> struct simd_size;
-template <class T, class Abi = simd_abi::compatible<T>>
-inline constexpr size_t simd_size_v = simd_size<T, Abi>::value;
-
-template <class T, class U = typename T::value_type> struct memory_alignment;
-template <class T, class U = typename T::value_type>
-inline constexpr size_t memory_alignment_v = memory_alignment<T, U>::value;
-
-// class template simd [simd.class]
-template <class T, class Abi = simd_abi::compatible<T>> class simd;
-template <class T> using native_simd = simd<T, simd_abi::native<T>>;
-template <class T, int N> using fixed_size_simd = simd<T, simd_abi::fixed_size<N>>;
-
-// class template simd_mask [simd.mask.class]
-template <class T, class Abi = simd_abi::compatible<T>> class simd_mask;
-template <class T> using native_simd_mask = simd_mask<T, simd_abi::native<T>>;
-template <class T, int N> using fixed_size_simd_mask = simd_mask<T, simd_abi::fixed_size<N>>;
-
-// casts [simd.casts]
-template <class T, class U, class Abi> see below simd_cast(const simd<U, Abi>&);
-template <class T, class U, class Abi> see below static_simd_cast(const simd<U, Abi>&);
-
-template <class T, class Abi>
-fixed_size_simd<T, simd_size_v<T, Abi>> to_fixed_size(const simd<T, Abi>&) noexcept;
-template <class T, class Abi>
-fixed_size_simd_mask<T, simd_size_v<T, Abi>> to_fixed_size(const simd_mask<T, Abi>&) noexcept;
-template <class T, size_t N> native_simd<T> to_native(const fixed_size_simd<T, N>&) noexcept;
-template <class T, size_t N>
-native_simd_mask<T> to_native(const fixed_size_simd_mask<T, N>> &) noexcept;
-template <class T, size_t N> simd<T> to_compatible(const fixed_size_simd<T, N>&) noexcept;
-template <class T, size_t N> simd_mask<T> to_compatible(const fixed_size_simd_mask<T, N>&) noexcept;
-
-template <size_t... Sizes, class T, class Abi>
-tuple<simd<T, abi_for_size_t<Sizes>>...> split(const simd<T, Abi>&);
-template <size_t... Sizes, class T, class Abi>
-tuple<simd_mask<T, abi_for_size_t<Sizes>>...> split(const simd_mask<T, Abi>&);
-template <class V, class Abi>
-array<V, simd_size_v<typename V::value_type, Abi> / V::size()> split(
-const simd<typename V::value_type, Abi>&);
-template <class V, class Abi>
-array<V, simd_size_v<typename V::value_type, Abi> / V::size()> split(
-const simd_mask<typename V::value_type, Abi>&);
-
-template <class T, class... Abis>
-simd<T, abi_for_size_t<T, (simd_size_v<T, Abis> + ...)>> concat(const simd<T, Abis>&...);
-template <class T, class... Abis>
-simd_mask<T, abi_for_size_t<T, (simd_size_v<T, Abis> + ...)>> concat(const simd_mask<T, Abis>&...);
-
-// reductions [simd.mask.reductions]
-template <class T, class Abi> bool all_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> bool any_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> bool none_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> bool some_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> int popcount(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> int find_first_set(const simd_mask<T, Abi>&);
-template <class T, class Abi> int find_last_set(const simd_mask<T, Abi>&);
-
-bool all_of(see below) noexcept;
-bool any_of(see below) noexcept;
-bool none_of(see below) noexcept;
-bool some_of(see below) noexcept;
-int popcount(see below) noexcept;
-int find_first_set(see below) noexcept;
-int find_last_set(see below) noexcept;
-
-// masked assignment [simd.whereexpr]
-template <class M, class T> class const_where_expression;
-template <class M, class T> class where_expression;
-
-// masked assignment [simd.mask.where]
-template <class T> struct nodeduce { using type = T; }; // exposition only
-
-template <class T> using nodeduce_t = typename nodeduce<T>::type; // exposition only
-
-template <class T, class Abi>
-where_expression<simd_mask<T, Abi>, simd<T, Abi>>
-where(const typename simd<T, Abi>::mask_type&, simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-const_where_expression<simd_mask<T, Abi>, const simd<T, Abi>>
-where(const typename simd<T, Abi>::mask_type&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-where_expression<simd_mask<T, Abi>, simd_mask<T, Abi>>
-where(const nodeduce_t<simd_mask<T, Abi>>&, simd_mask<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-const_where_expression<simd_mask<T, Abi>, const simd_mask<T, Abi>>
-where(const nodeduce_t<simd_mask<T, Abi>>&, const simd_mask<T, Abi>&) noexcept;
-
-template <class T> where_expression<bool, T> where(see below k, T& d) noexcept;
-
-template <class T>
-const_where_expression<bool, const T> where(see below k, const T& d) noexcept;
-
-// reductions [simd.reductions]
-template <class T, class Abi, class BinaryOperation = std::plus<>>
-T reduce(const simd<T, Abi>&, BinaryOperation = BinaryOperation());
-
-template <class M, class V, class BinaryOperation>
-typename V::value_type reduce(const const_where_expression<M, V>& x,
-typename V::value_type neutral_element, BinaryOperation binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, plus<> binary_op = plus<>());
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, multiplies<> binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, bit_and<> binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, bit_or<> binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, bit_xor<> binary_op);
-
-template <class T, class Abi> T hmin(const simd<T, Abi>&);
-template <class M, class V> T hmin(const const_where_expression<M, V>&);
-template <class T, class Abi> T hmax(const simd<T, Abi>&);
-template <class M, class V> T hmax(const const_where_expression<M, V>&);
-
-// algorithms [simd.alg]
-template <class T, class Abi> simd<T, Abi> min(const simd<T, Abi>&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi> simd<T, Abi> max(const simd<T, Abi>&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-std::pair<simd<T, Abi>, simd<T, Abi>> minmax(const simd<T, Abi>&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-simd<T, Abi> clamp(const simd<T, Abi>& v, const simd<T, Abi>& lo, const simd<T, Abi>& hi);
-
-// [simd.whereexpr]
-template <class M, class T>
-class const_where_expression {
-  const M& mask; // exposition only
-  T& data; // exposition only
-public:
-  const_where_expression(const const_where_expression&) = delete;
-  const_where_expression& operator=(const const_where_expression&) = delete;
-  remove_const_t<T> operator-() const &&;
-  template <class U, class Flags> void copy_to(U* mem, Flags f) const &&;
-};
-
-template <class M, class T>
-class where_expression : public const_where_expression<M, T> {
-public:
-  where_expression(const where_expression&) = delete;
-  where_expression& operator=(const where_expression&) = delete;
-  template <class U> void operator=(U&& x);
-  template <class U> void operator+=(U&& x);
-  template <class U> void operator-=(U&& x);
-  template <class U> void operator*=(U&& x);
-  template <class U> void operator/=(U&& x);
-  template <class U> void operator%=(U&& x);
-  template <class U> void operator&=(U&& x);
-  template <class U> void operator|=(U&& x);
-  template <class U> void operator^=(U&& x);
-  template <class U> void operator<<=(U&& x);
-  template <class U> void operator>>=(U&& x);
-  void operator++();
-  void operator++(int);
-  void operator--();
-  void operator--(int);
-  template <class U, class Flags> void copy_from(const U* mem, Flags);
-};
-
-// [simd.class]
-template <class T, class Abi> class simd {
-public:
-  using value_type = T;
-  using reference = see below;
-  using mask_type = simd_mask<T, Abi>;
-
-  using abi_type = Abi;
-  static constexpr size_t size() noexcept;
-  simd() = default;
-
-  // implicit type conversion constructor
-  template <class U> simd(const simd<U, simd_abi::fixed_size<size()>>&);
-
-  // implicit broadcast constructor (see below for constraints)
-  template <class U> simd(U&& value);
-
-  // generator constructor (see below for constraints)
-  template <class G> explicit simd(G&& gen);
-
-  // load constructor
-  template <class U, class Flags> simd(const U* mem, Flags f);
-
-  // loads [simd.load]
-  template <class U, class Flags> void copy_from(const U* mem, Flags f);
-
-  // stores [simd.store]
-  template <class U, class Flags> void copy_to(U* mem, Flags f) const;
-
-  // scalar access [simd.subscr]
-  reference operator[](size_t);
-  value_type operator[](size_t) const;
-
-  // unary operators [simd.unary]
-  simd& operator++();
-  simd operator++(int);
-  simd& operator--();
-  simd operator--(int);
-  mask_type operator!() const;
-  simd operator~() const; // see below
-  simd operator+() const;
-  simd operator-() const;
-
-  // binary operators [simd.binary]
-  friend simd operator+ (const simd&, const simd&);
-  friend simd operator- (const simd&, const simd&);
-  friend simd operator* (const simd&, const simd&);
-  friend simd operator/ (const simd&, const simd&);
-  friend simd operator% (const simd&, const simd&);
-  friend simd operator& (const simd&, const simd&);
-  friend simd operator| (const simd&, const simd&);
-  friend simd operator^ (const simd&, const simd&);
-  friend simd operator<<(const simd&, const simd&);
-  friend simd operator>>(const simd&, const simd&);
-  friend simd operator<<(const simd&, int);
-  friend simd operator>>(const simd&, int);
-
-  // compound assignment [simd.cassign]
-  friend simd& operator+= (simd&, const simd&);
-  friend simd& operator-= (simd&, const simd&);
-  friend simd& operator*= (simd&, const simd&);
-  friend simd& operator/= (simd&, const simd&);
-  friend simd& operator%= (simd&, const simd&);
-
-  friend simd& operator&= (simd&, const simd&);
-  friend simd& operator|= (simd&, const simd&);
-  friend simd& operator^= (simd&, const simd&);
-  friend simd& operator<<=(simd&, const simd&);
-  friend simd& operator>>=(simd&, const simd&);
-  friend simd& operator<<=(simd&, int);
-  friend simd& operator>>=(simd&, int);
-
-  // compares [simd.comparison]
-  friend mask_type operator==(const simd&, const simd&);
-  friend mask_type operator!=(const simd&, const simd&);
-  friend mask_type operator>=(const simd&, const simd&);
-  friend mask_type operator<=(const simd&, const simd&);
-  friend mask_type operator> (const simd&, const simd&);
-  friend mask_type operator< (const simd&, const simd&);
-};
-
-// [simd.math]
-template <class Abi> using scharv = simd<signed char, Abi>; // exposition only
-template <class Abi> using shortv = simd<short, Abi>; // exposition only
-template <class Abi> using intv = simd<int, Abi>; // exposition only
-template <class Abi> using longv = simd<long int, Abi>; // exposition only
-template <class Abi> using llongv = simd<long long int, Abi>; // exposition only
-template <class Abi> using floatv = simd<float, Abi>; // exposition only
-template <class Abi> using doublev = simd<double, Abi>; // exposition only
-template <class Abi> using ldoublev = simd<long double, Abi>; // exposition only
-template <class T, class V> using samesize = fixed_size_simd<T, V::size()>; // exposition only
-
-template <class Abi> floatv<Abi> acos(floatv<Abi> x);
-template <class Abi> doublev<Abi> acos(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> acos(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> asin(floatv<Abi> x);
-template <class Abi> doublev<Abi> asin(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> asin(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> atan(floatv<Abi> x);
-template <class Abi> doublev<Abi> atan(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> atan(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> atan2(floatv<Abi> y, floatv<Abi> x);
-template <class Abi> doublev<Abi> atan2(doublev<Abi> y, doublev<Abi> x);
-template <class Abi> ldoublev<Abi> atan2(ldoublev<Abi> y, ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> cos(floatv<Abi> x);
-template <class Abi> doublev<Abi> cos(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> cos(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> sin(floatv<Abi> x);
-template <class Abi> doublev<Abi> sin(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> sin(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> tan(floatv<Abi> x);
-template <class Abi> doublev<Abi> tan(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> tan(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> acosh(floatv<Abi> x);
-template <class Abi> doublev<Abi> acosh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> acosh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> asinh(floatv<Abi> x);
-template <class Abi> doublev<Abi> asinh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> asinh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> atanh(floatv<Abi> x);
-template <class Abi> doublev<Abi> atanh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> atanh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> cosh(floatv<Abi> x);
-template <class Abi> doublev<Abi> cosh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> cosh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> sinh(floatv<Abi> x);
-template <class Abi> doublev<Abi> sinh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> sinh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> tanh(floatv<Abi> x);
-template <class Abi> doublev<Abi> tanh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> tanh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> exp(floatv<Abi> x);
-template <class Abi> doublev<Abi> exp(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> exp(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> exp2(floatv<Abi> x);
-template <class Abi> doublev<Abi> exp2(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> exp2(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> expm1(floatv<Abi> x);
-template <class Abi> doublev<Abi> expm1(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> expm1(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> frexp(floatv<Abi> value, samesize<int, floatv<Abi>>* exp);
-template <class Abi> doublev<Abi> frexp(doublev<Abi> value, samesize<int, doublev<Abi>>* exp);
-template <class Abi> ldoublev<Abi> frexp(ldoublev<Abi> value, samesize<int, ldoublev<Abi>>* exp);
-
-template <class Abi> samesize<int, floatv<Abi>> ilogb(floatv<Abi> x);
-template <class Abi> samesize<int, doublev<Abi>> ilogb(doublev<Abi> x);
-template <class Abi> samesize<int, ldoublev<Abi>> ilogb(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> ldexp(floatv<Abi> x, samesize<int, floatv<Abi>> exp);
-template <class Abi> doublev<Abi> ldexp(doublev<Abi> x, samesize<int, doublev<Abi>> exp);
-template <class Abi> ldoublev<Abi> ldexp(ldoublev<Abi> x, samesize<int, ldoublev<Abi>> exp);
-
-template <class Abi> floatv<Abi> log(floatv<Abi> x);
-template <class Abi> doublev<Abi> log(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> log10(floatv<Abi> x);
-template <class Abi> doublev<Abi> log10(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log10(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> log1p(floatv<Abi> x);
-template <class Abi> doublev<Abi> log1p(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log1p(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> log2(floatv<Abi> x);
-template <class Abi> doublev<Abi> log2(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log2(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> logb(floatv<Abi> x);
-template <class Abi> doublev<Abi> logb(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> logb(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> modf(floatv<Abi> value, floatv<Abi>* iptr);
-template <class Abi> doublev<Abi> modf(doublev<Abi> value, doublev<Abi>* iptr);
-template <class Abi> ldoublev<Abi> modf(ldoublev<Abi> value, ldoublev<Abi>* iptr);
-
-template <class Abi> floatv<Abi> scalbn(floatv<Abi> x, samesize<int, floatv<Abi>> n);
-template <class Abi> doublev<Abi> scalbn(doublev<Abi> x, samesize<int, doublev<Abi>> n);
-template <class Abi> ldoublev<Abi> scalbn(ldoublev<Abi> x, samesize<int, ldoublev<Abi>> n);
-template <class Abi> floatv<Abi> scalbln(floatv<Abi> x, samesize<long int, floatv<Abi>> n);
-template <class Abi> doublev<Abi> scalbln(doublev<Abi> x, samesize<long int, doublev<Abi>> n);
-template <class Abi> ldoublev<Abi> scalbln(ldoublev<Abi> x, samesize<long int, ldoublev<Abi>> n);
-
-template <class Abi> floatv<Abi> cbrt(floatv<Abi> x);
-template <class Abi> doublev<Abi> cbrt(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> cbrt(ldoublev<Abi> x);
-
-template <class Abi> scharv<Abi> abs(scharv<Abi> j);
-template <class Abi> shortv<Abi> abs(shortv<Abi> j);
-template <class Abi> intv<Abi> abs(intv<Abi> j);
-template <class Abi> longv<Abi> abs(longv<Abi> j);
-template <class Abi> llongv<Abi> abs(llongv<Abi> j);
-template <class Abi> floatv<Abi> abs(floatv<Abi> j);
-template <class Abi> doublev<Abi> abs(doublev<Abi> j);
-template <class Abi> ldoublev<Abi> abs(ldoublev<Abi> j);
-
-template <class Abi> floatv<Abi> hypot(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> hypot(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> hypot(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> floatv<Abi> hypot(floatv<Abi> x, floatv<Abi> y, floatv<Abi> z);
-template <class Abi> doublev<Abi> hypot(doublev<Abi> x, doublev<Abi> y, doublev<Abi> z);
-template <class Abi> ldoublev<Abi> hypot(ldoublev<Abi> x, ldoublev<Abi> y, ldoublev<Abi> z);
-
-template <class Abi> floatv<Abi> pow(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> pow(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> pow(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> sqrt(floatv<Abi> x);
-template <class Abi> doublev<Abi> sqrt(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> sqrt(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> erf(floatv<Abi> x);
-template <class Abi> doublev<Abi> erf(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> erf(ldoublev<Abi> x);
-template <class Abi> floatv<Abi> erfc(floatv<Abi> x);
-template <class Abi> doublev<Abi> erfc(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> erfc(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> lgamma(floatv<Abi> x);
-template <class Abi> doublev<Abi> lgamma(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> lgamma(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> tgamma(floatv<Abi> x);
-template <class Abi> doublev<Abi> tgamma(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> tgamma(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> ceil(floatv<Abi> x);
-template <class Abi> doublev<Abi> ceil(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> ceil(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> floor(floatv<Abi> x);
-template <class Abi> doublev<Abi> floor(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> floor(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> nearbyint(floatv<Abi> x);
-template <class Abi> doublev<Abi> nearbyint(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> nearbyint(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> rint(floatv<Abi> x);
-template <class Abi> doublev<Abi> rint(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> rint(ldoublev<Abi> x);
-
-template <class Abi> samesize<long int, floatv<Abi>> lrint(floatv<Abi> x);
-template <class Abi> samesize<long int, doublev<Abi>> lrint(doublev<Abi> x);
-template <class Abi> samesize<long int, ldoublev<Abi>> lrint(ldoublev<Abi> x);
-template <class Abi> samesize<long long int, floatv<Abi>> llrint(floatv<Abi> x);
-template <class Abi> samesize<long long int, doublev<Abi>> llrint(doublev<Abi> x);
-template <class Abi> samesize<long long int, ldoublev<Abi>> llrint(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> round(floatv<Abi> x);
-template <class Abi> doublev<Abi> round(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> round(ldoublev<Abi> x);
-template <class Abi> samesize<long int, floatv<Abi>> lround(floatv<Abi> x);
-template <class Abi> samesize<long int, doublev<Abi>> lround(doublev<Abi> x);
-template <class Abi> samesize<long int, ldoublev<Abi>> lround(ldoublev<Abi> x);
-template <class Abi> samesize<long long int, floatv<Abi>> llround(floatv<Abi> x);
-template <class Abi> samesize<long long int, doublev<Abi>> llround(doublev<Abi> x);
-template <class Abi> samesize<long long int, ldoublev<Abi>> llround(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> trunc(floatv<Abi> x);
-template <class Abi> doublev<Abi> trunc(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> trunc(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> fmod(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fmod(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fmod(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> remainder(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> remainder(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> remainder(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> remquo(floatv<Abi> x, floatv<Abi> y, samesize<int, floatv<Abi>>* quo);
-template <class Abi> doublev<Abi> remquo(doublev<Abi> x, doublev<Abi> y, samesize<int, doublev<Abi>>* quo);
-template <class Abi> ldoublev<Abi> remquo(ldoublev<Abi> x, ldoublev<Abi> y, samesize<int, ldoublev<Abi>>* quo);
-
-template <class Abi> floatv<Abi> copysign(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> copysign(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> copysign(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> doublev<Abi> nan(const char* tagp);
-template <class Abi> floatv<Abi> nanf(const char* tagp);
-template <class Abi> ldoublev<Abi> nanl(const char* tagp);
-
-template <class Abi> floatv<Abi> nextafter(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> nextafter(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> nextafter(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> nexttoward(floatv<Abi> x, ldoublev<Abi> y);
-template <class Abi> doublev<Abi> nexttoward(doublev<Abi> x, ldoublev<Abi> y);
-template <class Abi> ldoublev<Abi> nexttoward(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fdim(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fdim(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fdim(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fmax(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fmax(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fmax(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fmin(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fmin(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fmin(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fma(floatv<Abi> x, floatv<Abi> y, floatv<Abi> z);
-template <class Abi> doublev<Abi> fma(doublev<Abi> x, doublev<Abi> y, doublev<Abi> z);
-template <class Abi> ldoublev<Abi> fma(ldoublev<Abi> x, ldoublev<Abi> y, ldoublev<Abi> z);
-
-template <class Abi> samesize<int, floatv<Abi>> fpclassify(floatv<Abi> x);
-template <class Abi> samesize<int, doublev<Abi>> fpclassify(doublev<Abi> x);
-template <class Abi> samesize<int, ldoublev<Abi>> fpclassify(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isfinite(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isfinite(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isfinite(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isinf(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isinf(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isinf(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isnan(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isnan(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isnan(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isnormal(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isnormal(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isnormal(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> signbit(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> signbit(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> signbit(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isgreater(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isgreater(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isgreater(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> isgreaterequal(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isgreaterequal(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isgreaterequal(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> isless(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isless(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isless(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> islessequal(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> islessequal(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> islessequal(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> islessgreater(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> islessgreater(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> islessgreater(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> isunordered(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isunordered(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isunordered(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class V> struct simd_div_t { V quot, rem; };
-template <class Abi> simd_div_t<scharv<Abi>> div(scharv<Abi> numer, scharv<Abi> denom);
-template <class Abi> simd_div_t<shortv<Abi>> div(shortv<Abi> numer, shortv<Abi> denom);
-template <class Abi> simd_div_t<intv<Abi>> div(intv<Abi> numer, intv<Abi> denom);
-template <class Abi> simd_div_t<longv<Abi>> div(longv<Abi> numer, longv<Abi> denom);
-template <class Abi> simd_div_t<llongv<Abi>> div(llongv<Abi> numer, llongv<Abi> denom);
-
-// [simd.mask.class]
-template <class T, class Abi>
-class simd_mask {
-public:
-  using value_type = bool;
-  using reference = see below;
-  using simd_type = simd<T, Abi>;
-  using abi_type = Abi;
-  static constexpr size_t size() noexcept;
-  simd_mask() = default;
-
-  // broadcast constructor
-  explicit simd_mask(value_type) noexcept;
-
-  // implicit type conversion constructor
-  template <class U> simd_mask(const simd_mask<U, simd_abi::fixed_size<size()>>&) noexcept;
-
-  // load constructor
-  template <class Flags> simd_mask(const value_type* mem, Flags);
-
-  // loads [simd.mask.copy]
-  template <class Flags> void copy_from(const value_type* mem, Flags);
-  template <class Flags> void copy_to(value_type* mem, Flags) const;
-
-  // scalar access [simd.mask.subscr]
-  reference operator[](size_t);
-  value_type operator[](size_t) const;
-
-  // unary operators [simd.mask.unary]
-  simd_mask operator!() const noexcept;
-
-  // simd_mask binary operators [simd.mask.binary]
-  friend simd_mask operator&&(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator||(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator& (const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator| (const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator^ (const simd_mask&, const simd_mask&) noexcept;
-
-  // simd_mask compound assignment [simd.mask.cassign]
-  friend simd_mask& operator&=(simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask& operator|=(simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask& operator^=(simd_mask&, const simd_mask&) noexcept;
-
-  // simd_mask compares [simd.mask.comparison]
-  friend simd_mask operator==(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator!=(const simd_mask&, const simd_mask&) noexcept;
-};
-
+  struct element_aligned_tag {};
+  struct vector_aligned_tag {};
+  template<size_t> struct overaligned_tag {};
+  inline constexpr element_aligned_tag element_aligned{};
+  inline constexpr vector_aligned_tag vector_aligned{};
+  template<size_t N> inline constexpr overaligned_tag<N> overaligned{};
+
+  // 9.4, simd type traits
+  template<class T> struct is_abi_tag;
+  template<class T> inline constexpr bool is_abi_tag_v = is_abi_tag<T>::value;
+
+  template<class T> struct is_simd;
+  template<class T> inline constexpr bool is_simd_v = is_simd<T>::value
+
+  template<class T> struct is_simd_mask;
+  template<class T> inline constexpr bool is_simd_mask_v = is_simd_mask<T>::value;
+
+  template<class T> struct is_simd_flag_type;
+  template<class T> inline constexpr bool is_simd_flag_type_v =
+    is_simd_flag_type<T>::value;
+
+  template<class T, class Abi = simd_abi::compatible<T>> struct simd_size;
+  template<class T, class Abi = simd_abi::compatible<T>>
+    inline constexpr size_t simd_size_v = simd_size<T,Abi>::value;
+
+  template<class T, class U = typename T::value_type> struct memory_alignment;
+  template<class T, class U = typename T::value_type>
+    inline constexpr size_t memory_alignment_v = memory_alignment<T,U>::value;
+
+  template<class T, class V> struct rebind_simd { using type = see below; };
+  template<class T, class V> using rebind_simd_t = typename rebind_simd<T, V>::type;
+  template<int N, class V> struct resize_simd { using type = see below; };
+  template<int N, class V> using resize_simd_t = typename resize_simd<N, V>::type;
+
+  // 9.6, Class template simd
+  template<class T, class Abi = simd_abi::compatible<T>> class simd;
+  template<class T> using native_simd = simd<T, simd_abi::native<T>>;
+  template<class T, int N> using fixed_size_simd = simd<T, simd_abi::fixed_size<N>>;
+
+  // 9.8, Class template simd_mask
+  template<class T, class Abi = simd_abi::compatible<T>> class simd_mask;
+  template<class T> using native_simd_mask = simd_mask<T, simd_abi::native<T>>;
+  template<class T, int N> using fixed_size_simd_mask =
+    simd_mask<T, simd_abi::fixed_size<N>>;
+
+  // 9.7.5, Casts
+  template<class T, class U, class Abi> see below simd_cast(const simd<U, Abi>&) noexcept;
+  template<class T, class U, class Abi> see below static_simd_cast(const simd<U, Abi>&) noexcept;
+
+  template<class T, class Abi>
+    fixed_size_simd<T, simd_size_v<T, Abi>>
+      to_fixed_size(const simd<T, Abi>&) noexcept;
+  template<class T, class Abi>
+    fixed_size_simd_mask<T, simd_size_v<T, Abi>>
+      to_fixed_size(const simd_mask<T, Abi>&) noexcept;
+  template<class T, int N>
+    native_simd<T> to_native(const fixed_size_simd<T, N>&) noexcept;
+  template<class T, int N>
+    native_simd_mask<T> to_native(const fixed_size_simd_mask<T, N>&) noexcept;
+  template<class T, int N>
+    simd<T> to_compatible(const fixed_size_simd<T, N>&) noexcept;
+  template<class T, int N>
+    simd_mask<T> to_compatible(const fixed_size_simd_mask<T, N>&) noexcept;
+
+  template<size_t... Sizes, class T, class Abi>
+    tuple<simd<T, simd_abi::deduce_t<T, Sizes>>...>
+      split(const simd<T, Abi>&) noexcept;
+  template<size_t... Sizes, class T, class Abi>
+    tuple<simd_mask<T, simd_abi::deduce_t<T, Sizes>>...>
+      split(const simd_mask<T, Abi>&) noexcept;
+  template<class V, class Abi>
+    array<V, simd_size_v<typename V::value_type, Abi> / V::size()>
+      split(const simd<typename V::value_type, Abi>&) noexcept;
+  template<class V, class Abi>
+    array<V, simd_size_v<typename V::simd_type::value_type, Abi> / V::size()>
+      split(const simd_mask<typename V::simd_type::value_type, Abi>&) noexcept;
+
+  template<size_t N, class T, class A>
+    array<resize_simd<simd_size_v<T, A> / N, simd<T, A>>, N>
+      split_by(const simd<T, A>& x) noexcept;
+  template<size_t N, class T, class A>
+    array<resize_simd<simd_size_v<T, A> / N, simd_mask<T, A>>, N>
+      split_by(const simd_mask<T, A>& x) noexcept;
+
+  template<class T, class... Abis>
+    simd<T, simd_abi::deduce_t<T, (simd_size_v<T, Abis> + ...)>>
+      concat(const simd<T, Abis>&...) noexcept;
+  template<class T, class... Abis>
+    simd_mask<T, simd_abi::deduce_t<T, (simd_size_v<T, Abis> + ...)>>
+      concat(const simd_mask<T, Abis>&...) noexcept;
+
+  template<class T, class Abi, size_t N>
+    resize_simd<simd_size_v<T, Abi> * N, simd<T, Abi>>
+      concat(const array<simd<T, Abi>, N>& arr) noexcept;
+  template<class T, class Abi, size_t N>
+    resize_simd<simd_size_v<T, Abi> * N, simd_mask<T, Abi>>
+      concat(const array<simd_mask<T, Abi>, N>& arr) noexcept;
+
+  // 9.9.4, Reductions
+  template<class T, class Abi> bool all_of(const simd_mask<T, Abi>&) noexcept;
+  template<class T, class Abi> bool any_of(const simd_mask<T, Abi>&) noexcept;
+  template<class T, class Abi> bool none_of(const simd_mask<T, Abi>&) noexcept;
+  template<class T, class Abi> bool some_of(const simd_mask<T, Abi>&) noexcept;
+  template<class T, class Abi> int popcount(const simd_mask<T, Abi>&) noexcept;
+  template<class T, class Abi> int find_first_set(const simd_mask<T, Abi>&);
+  template<class T, class Abi> int find_last_set(const simd_mask<T, Abi>&);
+
+  bool all_of(T) noexcept;
+  bool any_of(T) noexcept;
+  bool none_of(T) noexcept;
+  bool some_of(T) noexcept;
+  int popcount(T) noexcept;
+  int find_first_set(T);
+  int find_last_set(T);
+
+  // 9.5, Where expression class templates
+  template<class M, class T> class const_where_expression;
+  template<class M, class T> class where_expression;
+
+  // 9.9.5, Where functions
+  template<class T, class Abi>
+    where_expression<simd_mask<T, Abi>, simd<T, Abi>>
+      where(const typename simd<T, Abi>::mask_type&, simd<T, Abi>&) noexcept;
+
+  template<class T, class Abi>
+    const_where_expression<simd_mask<T, Abi>, simd<T, Abi>>
+      where(const typename simd<T, Abi>::mask_type&, const simd<T, Abi>&) noexcept;
+
+  template<class T, class Abi>
+    where_expression<simd_mask<T, Abi>, simd_mask<T, Abi>>
+      where(const type_identity_t<simd_mask<T, Abi>>&, simd_mask<T, Abi>&) noexcept;
+
+  template<class T, class Abi>
+    const_where_expression<simd_mask<T, Abi>, simd_mask<T, Abi>>
+      where(const type_identity_t<simd_mask<T, Abi>>&, const simd_mask<T, Abi>&) noexcept;
+
+  template<class T>
+    where_expression<bool, T>
+      where(see below k, T& d) noexcept;
+
+  template<class T>
+    const_where_expression<bool, T>
+      where(see below k, const T& d) noexcept;
+
+  // 9.7.4, Reductions
+  template<class T, class Abi, class BinaryOperation = plus<>>
+    T reduce(const simd<T, Abi>&,
+             BinaryOperation = {});
+
+  template<class M, class V, class BinaryOperation>
+    typename V::value_type reduce(const const_where_expression<M, V>& x,
+                                  typename V::value_type identity_element,
+                                  BinaryOperation binary_op);
+  template<class M, class V>
+    typename V::value_type reduce(const const_where_expression<M, V>& x,
+                                  plus<> binary_op = {}) noexcept;
+  template<class M, class V>
+    typename V::value_type reduce(const const_where_expression<M, V>& x,
+                                  multiplies<> binary_op) noexcept;
+  template<class M, class V>
+    typename V::value_type reduce(const const_where_expression<M, V>& x,
+                                  bit_and<> binary_op) noexcept;
+  template<class M, class V>
+    typename V::value_type reduce(const const_where_expression<M, V>& x,
+                                  bit_or<> binary_op) noexcept;
+  template<class M, class V>
+    typename V::value_type reduce(const const_where_expression<M, V>& x,
+                                  bit_xor<> binary_op) noexcept;
+
+  template<class T, class Abi>
+    T hmin(const simd<T, Abi>&) noexcept;
+  template<class M, class V>
+    typename V::value_type hmin(const const_where_expression<M, V>&) noexcept;
+  template<class T, class Abi>
+    T hmax(const simd<T, Abi>&) noexcept;
+  template<class M, class V>
+    typename V::value_type hmax(const const_where_expression<M, V>&) noexcept;
+
+  // 9.7.6, Algorithms
+  template<class T, class Abi>
+    simd<T, Abi>
+      min(const simd<T, Abi>& a, const simd<T, Abi>& b) noexcept;
+  template<class T, class Abi>
+    simd<T, Abi>
+      max(const simd<T, Abi>& a, const simd<T, Abi>& b) noexcept;
+  template<class T, class Abi>
+    pair<simd<T, Abi>, simd<T, Abi>>
+      minmax(const simd<T, Abi>& a, const simd<T, Abi>& b) noexcept;
+  template<class T, class Abi>
+    simd<T, Abi>
+      clamp(const simd<T, Abi>& v,
+            const simd<T, Abi>& lo,
+            const simd<T, Abi>& hi);
 } // parallelism_v2
 } // std::experimental
 
@@ -653,8 +230,10 @@
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__functional/operations.h>
 #include <array>
-#include <cstddef>
 #include <experimental/__config>
+#include <experimental/__simd/scalar.h>
+#include <experimental/__simd/utility.h>
+#include <experimental/__simd/vec_ext.h>
 #include <tuple>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -664,917 +243,425 @@
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD
-
 #if _LIBCPP_STD_VER >= 17
 
-enum class _StorageKind {
-  _Scalar,
-  _Array,
-  _VecExt,
-};
-
-template <_StorageKind __kind, int _Np>
-struct __simd_abi {};
-
-template <class _Tp, class _Abi>
-class __simd_storage {};
-
-template <class _Tp, int __num_element>
-class __simd_storage<_Tp, __simd_abi<_StorageKind::_Array, __num_element>> {
-  std::array<_Tp, __num_element> __storage_;
-
-  template <class, class>
-  friend struct simd;
-
-  template <class, class>
-  friend struct simd_mask;
-
-public:
-  _Tp __get(size_t __index) const noexcept { return __storage_[__index]; }
-  void __set(size_t __index, _Tp __val) noexcept {
-    __storage_[__index] = __val;
-  }
-};
-
-template <class _Tp>
-class __simd_storage<_Tp, __simd_abi<_StorageKind::_Scalar, 1>> {
-  _Tp __storage_;
-
-  template <class, class>
-  friend struct simd;
-
-  template <class, class>
-  friend struct simd_mask;
-
-public:
-  _Tp __get(size_t __index) const noexcept { return (&__storage_)[__index]; }
-  void __set(size_t __index, _Tp __val) noexcept {
-    (&__storage_)[__index] = __val;
-  }
-};
-
-#ifndef _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-_LIBCPP_HIDE_FROM_ABI constexpr size_t __floor_pow_of_2(size_t __val) {
-  return ((__val - 1) & __val) == 0 ? __val
-                                    : __floor_pow_of_2((__val - 1) & __val);
-}
+_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD_ABI
 
-_LIBCPP_HIDE_FROM_ABI constexpr size_t __ceil_pow_of_2(size_t __val) {
-  return __val == 1 ? 1 : __floor_pow_of_2(__val - 1) << 1;
-}
+using scalar = __scalar;
+template<int _Np> using fixed_size = __vec_ext<_Np>;
+template<class _Tp> inline constexpr int max_fixed_size = 32;
+template<class _Tp> using compatible = __vec_ext<16 / sizeof(_Tp)>;
+template<class _Tp> using native = __vec_ext<_LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES / sizeof(_Tp)>;
 
-template <class _Tp, size_t __bytes>
-struct __vec_ext_traits {
-#if !defined(_LIBCPP_COMPILER_CLANG_BASED)
-  typedef _Tp type __attribute__((vector_size(__ceil_pow_of_2(__bytes))));
-#endif
+// TODO: Refine implementation-defined deduce ABI
+template<class _Tp, size_t _Np, class... Abis> struct deduce {
+  using type = fixed_size<_Np>;
 };
+template<class _Tp, size_t _Np, class... _Abis> using deduce_t =
+  typename deduce<_Tp, _Np, _Abis...>::type;
 
-#if defined(_LIBCPP_COMPILER_CLANG_BASED)
-#define _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, _NUM_ELEMENT)                        \
-  template <>                                                                  \
-  struct __vec_ext_traits<_TYPE, sizeof(_TYPE) * _NUM_ELEMENT> {               \
-    using type =                                                               \
-        _TYPE __attribute__((vector_size(sizeof(_TYPE) * _NUM_ELEMENT)));      \
-  }
-
-#define _LIBCPP_SPECIALIZE_VEC_EXT_32(_TYPE)                                   \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 1);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 2);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 3);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 4);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 5);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 6);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 7);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 8);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 9);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 10);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 11);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 12);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 13);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 14);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 15);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 16);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 17);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 18);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 19);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 20);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 21);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 22);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 23);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 24);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 25);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 26);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 27);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 28);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 29);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 30);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 31);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 32)
-
-_LIBCPP_SPECIALIZE_VEC_EXT_32(char);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(char16_t);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(char32_t);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(wchar_t);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed char);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed short);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed int);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed long long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned char);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned short);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned int);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned long long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(float);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(double);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(long double);
-
-#undef _LIBCPP_SPECIALIZE_VEC_EXT_32
-#undef _LIBCPP_SPECIALIZE_VEC_EXT
-#endif
-
-template <class _Tp, int __num_element>
-class __simd_storage<_Tp, __simd_abi<_StorageKind::_VecExt, __num_element>> {
-  using _StorageType =
-      typename __vec_ext_traits<_Tp, sizeof(_Tp) * __num_element>::type;
-
-  _StorageType __storage_;
-
-  template <class, class>
-  friend struct simd;
+_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD_ABI
 
-  template <class, class>
-  friend struct simd_mask;
+_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD
 
+template<class _Vp> class __simd_reference { // exposition only
 public:
-  _Tp __get(size_t __index) const noexcept { return __storage_[__index]; }
-  void __set(size_t __index, _Tp __val) noexcept {
-    __storage_[__index] = __val;
-  }
-};
-
-#endif // _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-template <class _Vp, class _Tp, class _Abi>
-class __simd_reference {
-  static_assert(std::is_same<_Vp, _Tp>::value, "");
-
-  template <class, class>
-  friend struct simd;
-
-  template <class, class>
-  friend struct simd_mask;
+  using value_type = _Vp;
 
-  __simd_storage<_Tp, _Abi>* __ptr_;
-  size_t __index_;
-
-  __simd_reference(__simd_storage<_Tp, _Abi>* __ptr, size_t __index)
-      : __ptr_(__ptr), __index_(__index) {}
-
-  __simd_reference(const __simd_reference&) = default;
-
-public:
   __simd_reference() = delete;
-  __simd_reference& operator=(const __simd_reference&) = delete;
-
-  operator _Vp() const { return __ptr_->__get(__index_); }
-
-  __simd_reference operator=(_Vp __value) && {
-    __ptr_->__set(__index_, __value);
-    return *this;
-  }
-
-  __simd_reference operator++() && {
-    return std::move(*this) = __ptr_->__get(__index_) + 1;
-  }
-
-  _Vp operator++(int) && {
-    auto __val = __ptr_->__get(__index_);
-    __ptr_->__set(__index_, __val + 1);
-    return __val;
-  }
-
-  __simd_reference operator--() && {
-    return std::move(*this) = __ptr_->__get(__index_) - 1;
-  }
-
-  _Vp operator--(int) && {
-    auto __val = __ptr_->__get(__index_);
-    __ptr_->__set(__index_, __val - 1);
-    return __val;
-  }
-
-  __simd_reference operator+=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) + __value;
-  }
-
-  __simd_reference operator-=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) - __value;
-  }
-
-  __simd_reference operator*=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) * __value;
-  }
-
-  __simd_reference operator/=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) / __value;
-  }
-
-  __simd_reference operator%=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) % __value;
-  }
-
-  __simd_reference operator>>=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) >> __value;
-  }
-
-  __simd_reference operator<<=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) << __value;
-  }
-
-  __simd_reference operator&=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) & __value;
-  }
-
-  __simd_reference operator|=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) | __value;
-  }
-
-  __simd_reference operator^=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) ^ __value;
-  }
-};
-
-template <class _To, class _From>
-_LIBCPP_HIDE_FROM_ABI constexpr decltype(_To{std::declval<_From>()}, true)
-__is_non_narrowing_convertible_impl(_From) {
-  return true;
-}
-
-template <class _To>
-_LIBCPP_HIDE_FROM_ABI constexpr bool __is_non_narrowing_convertible_impl(...) {
-  return false;
-}
-
-template <class _From, class _To>
-_LIBCPP_HIDE_FROM_ABI
-constexpr typename std::enable_if<std::is_arithmetic<_To>::value &&
-                                      std::is_arithmetic<_From>::value,
-                                  bool>::type
-__is_non_narrowing_arithmetic_convertible() {
-  return experimental::__is_non_narrowing_convertible_impl<_To>(_From{});
-}
-
-template <class _From, class _To>
-_LIBCPP_HIDE_FROM_ABI
-constexpr typename std::enable_if<!(std::is_arithmetic<_To>::value &&
-                                    std::is_arithmetic<_From>::value),
-                                  bool>::type
-__is_non_narrowing_arithmetic_convertible() {
-  return false;
-}
-
-template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr _Tp __variadic_sum() {
-  return _Tp{};
-}
-
-template <class _Tp, class _Up, class... _Args>
-_LIBCPP_HIDE_FROM_ABI constexpr _Tp __variadic_sum(_Up __first, _Args... __rest) {
-  return static_cast<_Tp>(__first) + experimental::__variadic_sum<_Tp>(__rest...);
-}
-
-template <class _Tp>
-struct __nodeduce {
-  using type = _Tp;
+  __simd_reference(const __simd_reference&) = delete;
+
+  operator value_type() const noexcept;
+
+  template<class _Up> __simd_reference operator=(_Up&& __x) && noexcept;
+
+  template<class _Up> __simd_reference operator+=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator-=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator*=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator/=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator%=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator|=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator&=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator^=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator<<=(_Up&& __x) && noexcept;
+  template<class _Up> __simd_reference operator>>=(_Up&& __x) && noexcept;
+
+  __simd_reference operator++() && noexcept;
+  value_type operator++(int) && noexcept;
+  __simd_reference operator--() && noexcept;
+  value_type operator--(int) && noexcept;
+
+  friend void swap(__simd_reference&& __a, __simd_reference&& __b) noexcept;
+  friend void swap(value_type& __a, __simd_reference&& __b) noexcept;
+  friend void swap(__simd_reference&& __a, value_type& __b) noexcept;
 };
 
-template <class _Tp>
-_LIBCPP_HIDE_FROM_ABI constexpr bool __vectorizable() {
-  return std::is_arithmetic<_Tp>::value && !std::is_const<_Tp>::value &&
-         !std::is_volatile<_Tp>::value && !std::is_same<_Tp, bool>::value;
-}
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD_ABI
-
-using scalar = __simd_abi<_StorageKind::_Scalar, 1>;
-
-template <int _Np>
-using fixed_size = __simd_abi<_StorageKind::_Array, _Np>;
-
-template <class _Tp>
-inline constexpr size_t max_fixed_size = 32;
-
-template <class _Tp>
-using compatible = fixed_size<16 / sizeof(_Tp)>;
-
-#ifndef _LIBCPP_HAS_NO_VECTOR_EXTENSION
-template <class _Tp>
-using native = __simd_abi<_StorageKind::_VecExt,
-                          _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES / sizeof(_Tp)>;
-#else
-template <class _Tp>
-using native =
-    fixed_size<_Tp, _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES / sizeof(_Tp)>;
-#endif // _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD_ABI
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD
-
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-class simd;
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-class simd_mask;
-
 struct element_aligned_tag {};
 struct vector_aligned_tag {};
-template <size_t>
-struct overaligned_tag {};
+template<size_t> struct overaligned_tag {};
 inline constexpr element_aligned_tag element_aligned{};
 inline constexpr vector_aligned_tag vector_aligned{};
-template <size_t _Np>
-inline constexpr overaligned_tag<_Np> overaligned{};
-
-// traits [simd.traits]
-template <class _Tp>
-struct is_abi_tag : std::integral_constant<bool, false> {};
-
-template <_StorageKind __kind, int _Np>
-struct is_abi_tag<__simd_abi<__kind, _Np>>
-    : std::integral_constant<bool, true> {};
-
-template <class _Tp>
-struct is_simd : std::integral_constant<bool, false> {};
-
-template <class _Tp, class _Abi>
-struct is_simd<simd<_Tp, _Abi>> : std::integral_constant<bool, true> {};
-
-template <class _Tp>
-struct is_simd_mask : std::integral_constant<bool, false> {};
+template<size_t _Np> inline constexpr overaligned_tag<_Np> overaligned{};
+
+// 9.6, Class template simd
+template<class _Tp, class _Abi = simd_abi::compatible<_Tp>> class simd;
+template<class _Tp> using native_simd = simd<_Tp, simd_abi::native<_Tp>>;
+template<class _Tp, int _Np> using fixed_size_simd = simd<_Tp, simd_abi::fixed_size<_Np>>;
+
+// 9.8, Class template simd_mask
+template<class _Tp, class _Abi = simd_abi::compatible<_Tp>> class simd_mask;
+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>>;
+
+// 9.4, simd type traits
+template<class _Tp, class = void> struct __is_abi_tag_impl : false_type {};
+template<class _Tp> struct __is_abi_tag_impl<_Tp, enable_if_t<_Tp::__is_abi_tag>> : bool_constant<_Tp::__is_abi_tag> {};
+template<class _Tp> struct is_abi_tag : __is_abi_tag_impl<_Tp> {};
+template<class _Tp> inline constexpr bool is_abi_tag_v = is_abi_tag<_Tp>::value;
+
+template<class _Tp> struct is_simd;
+template<class _Tp> inline constexpr bool is_simd_v = is_simd<_Tp>::value;
+
+template<class _Tp> struct is_simd_mask;
+template<class _Tp> inline constexpr bool is_simd_mask_v = is_simd_mask<_Tp>::value;
+
+template<class _Tp> struct is_simd_flag_type;
+template<class _Tp> inline constexpr bool is_simd_flag_type_v = is_simd_flag_type<_Tp>::value;
+
+template<class _Tp, class _Abi, class = void> struct __simd_size_impl {};
+template<class _Tp, class _Abi>
+  struct __simd_size_impl<_Tp, _Abi, enable_if_t<__is_vectorizable<_Tp>() && is_abi_tag_v<_Abi>>>
+    : integral_constant<size_t, _Abi::__simd_size> {};
+template<class _Tp, class _Abi = simd_abi::compatible<_Tp>> struct simd_size : __simd_size_impl<_Tp, _Abi> {};
+template<class _Tp, class _Abi = simd_abi::compatible<_Tp>>
+  inline constexpr size_t simd_size_v = simd_size<_Tp, _Abi>::value;
+
+template<class _Tp, class _Up = typename _Tp::value_type> struct memory_alignment;
+template<class _Tp, class _Up = typename _Tp::value_type>
+  inline constexpr size_t memory_alignment_v = memory_alignment<_Tp, _Up>::value;
+
+template<class _Tp, class _Vp> struct rebind_simd { using type = void; };
+template<class _Tp, class _Vp> using rebind_simd_t = typename rebind_simd<_Tp, _Vp>::type;
+template<int _Np, class _Vp> struct resize_simd { using type = void; };
+template<int _Np, class _Vp> using resize_simd_t = typename resize_simd<_Np, _Vp>::type;
+
+// 9.7.5, Casts
+template<class _Tp, class _Up, class _Abi> void simd_cast(const simd<_Up, _Abi>&) noexcept;
+template<class _Tp, class _Up, class _Abi> void static_simd_cast(const simd<_Up, _Abi>&) noexcept;
+
+template<class _Tp, class _Abi>
+  fixed_size_simd<_Tp, simd_size_v<_Tp, _Abi>>
+    to_fixed_size(const simd<_Tp, _Abi>&) noexcept;
+template<class _Tp, class _Abi>
+  fixed_size_simd_mask<_Tp, simd_size_v<_Tp, _Abi>>
+    to_fixed_size(const simd_mask<_Tp, _Abi>&) noexcept;
+template<class _Tp, int _Np>
+  native_simd<_Tp> to_native(const fixed_size_simd<_Tp, _Np>&) noexcept;
+template<class _Tp, int _Np>
+  native_simd_mask<_Tp> to_native(const fixed_size_simd_mask<_Tp, _Np>&) noexcept;
+template<class _Tp, int _Np>
+  simd<_Tp> to_compatible(const fixed_size_simd<_Tp, _Np>&) noexcept;
+template<class _Tp, int _Np>
+  simd_mask<_Tp> to_compatible(const fixed_size_simd_mask<_Tp, _Np>&) noexcept;
+
+template<size_t... _Sizes, class _Tp, class _Abi>
+  tuple<simd<_Tp, simd_abi::deduce_t<_Tp, _Sizes>>...>
+    split(const simd<_Tp, _Abi>&) noexcept;
+template<size_t... _Sizes, class _Tp, class _Abi>
+  tuple<simd_mask<_Tp, simd_abi::deduce_t<_Tp, _Sizes>>...>
+    split(const simd_mask<_Tp, _Abi>&) noexcept;
+template<class _Vp, class _Abi>
+  array<_Vp, simd_size_v<typename _Vp::value_type, _Abi> / _Vp::size()>
+    split(const simd<typename _Vp::value_type, _Abi>&) noexcept;
+template<class _Vp, class _Abi>
+  array<_Vp, simd_size_v<typename _Vp::simd_type::value_type, _Abi> / _Vp::size()>
+    split(const simd_mask<typename _Vp::simd_type::value_type, _Abi>&) noexcept;
+
+template<size_t _Np, class _Tp, class _Abi>
+  array<resize_simd<simd_size_v<_Tp, _Abi> / _Np, simd<_Tp, _Abi>>, _Np>
+    split_by(const simd<_Tp, _Abi>& __x) noexcept;
+template<size_t _Np, class _Tp, class _Abi>
+  array<resize_simd<simd_size_v<_Tp, _Abi> / _Np, simd_mask<_Tp, _Abi>>, _Np>
+    split_by(const simd_mask<_Tp, _Abi>& __x) noexcept;
+
+template<class _Tp, class... _Abis>
+  simd<_Tp, simd_abi::deduce_t<_Tp, (simd_size_v<_Tp, _Abis> + ...)>>
+    concat(const simd<_Tp, _Abis>&...) noexcept;
+template<class _Tp, class... _Abis>
+  simd_mask<_Tp, simd_abi::deduce_t<_Tp, (simd_size_v<_Tp, _Abis> + ...)>>
+    concat(const simd_mask<_Tp, _Abis>&...) noexcept;
+
+template<class _Tp, class _Abi, size_t _Np>
+  resize_simd<simd_size_v<_Tp, _Abi> * _Np, simd<_Tp, _Abi>>
+    concat(const array<simd<_Tp, _Abi>, _Np>& __arr) noexcept;
+template<class _Tp, class _Abi, size_t _Np>
+  resize_simd<simd_size_v<_Tp, _Abi> * _Np, simd_mask<_Tp, _Abi>>
+    concat(const array<simd_mask<_Tp, _Abi>, _Np>& __arr) noexcept;
+
+// 9.9.4, Reductions
+template<class _Tp, class _Abi> bool all_of(const simd_mask<_Tp, _Abi>&) noexcept;
+template<class _Tp, class _Abi> bool any_of(const simd_mask<_Tp, _Abi>&) noexcept;
+template<class _Tp, class _Abi> bool none_of(const simd_mask<_Tp, _Abi>&) noexcept;
+template<class _Tp, class _Abi> bool some_of(const simd_mask<_Tp, _Abi>&) noexcept;
+template<class _Tp, class _Abi> int popcount(const simd_mask<_Tp, _Abi>&) noexcept;
+template<class _Tp, class _Abi> int find_first_set(const simd_mask<_Tp, _Abi>&);
+template<class _Tp, class _Abi> int find_last_set(const simd_mask<_Tp, _Abi>&);
+
+bool all_of(_Bool) noexcept;
+bool any_of(_Bool) noexcept;
+bool none_of(_Bool) noexcept;
+bool some_of(_Bool) noexcept;
+int popcount(_Bool) noexcept;
+int find_first_set(_Bool);
+int find_last_set(_Bool);
+
+// 9.5, Where expression class templates
+template<class _Mp, class _Tp> class const_where_expression;
+template<class _Mp, class _Tp> class where_expression;
+
+// 9.9.5, Where functions
+template<class _Tp, class _Abi>
+  where_expression<simd_mask<_Tp, _Abi>, simd<_Tp, _Abi>>
+    where(const typename simd<_Tp, _Abi>::mask_type&, simd<_Tp, _Abi>&) noexcept;
+
+template<class _Tp, class _Abi>
+  const_where_expression<simd_mask<_Tp, _Abi>, simd<_Tp, _Abi>>
+    where(const typename simd<_Tp, _Abi>::mask_type&, const simd<_Tp, _Abi>&) noexcept;
+
+template<class _Tp, class _Abi>
+  where_expression<simd_mask<_Tp, _Abi>, simd_mask<_Tp, _Abi>>
+    where(const type_identity_t<simd_mask<_Tp, _Abi>>&, simd_mask<_Tp, _Abi>&) noexcept;
+
+template<class _Tp, class _Abi>
+  const_where_expression<simd_mask<_Tp, _Abi>, simd_mask<_Tp, _Abi>>
+    where(const type_identity_t<simd_mask<_Tp, _Abi>>&, const simd_mask<_Tp, _Abi>&) noexcept;
+
+template<class _Tp>
+  where_expression<bool, _Tp>
+    where(_Bool __k, _Tp& __d) noexcept;
+
+template<class _Tp>
+  const_where_expression<bool, _Tp>
+    where(_Bool __k, const _Tp& __d) noexcept;
+
+
+// 9.7.4, Reductions
+template<class _Tp, class _Abi, class _BinaryOperation = plus<>>
+  _Tp reduce(const simd<_Tp, _Abi>&,
+            _BinaryOperation = {});
+
+template<class _Mp, class _Vp, class _BinaryOperation>
+  typename _Vp::value_type reduce(const const_where_expression<_Mp, _Vp>& __x,
+                                typename _Vp::value_type __identity_element,
+                                _BinaryOperation __binary_op);
+template<class _Mp, class _Vp>
+  typename _Vp::value_type reduce(const const_where_expression<_Mp, _Vp>& __x,
+                                plus<> __binary_op = {}) noexcept;
+template<class _Mp, class _Vp>
+  typename _Vp::value_type reduce(const const_where_expression<_Mp, _Vp>& __x,
+                                multiplies<> __binary_op) noexcept;
+template<class _Mp, class _Vp>
+  typename _Vp::value_type reduce(const const_where_expression<_Mp, _Vp>& __x,
+                                bit_and<> __binary_op) noexcept;
+template<class _Mp, class _Vp>
+  typename _Vp::value_type reduce(const const_where_expression<_Mp, _Vp>& __x,
+                                bit_or<> __binary_op) noexcept;
+template<class _Mp, class _Vp>
+  typename _Vp::value_type reduce(const const_where_expression<_Mp, _Vp>& __x,
+                                bit_xor<> __binary_op) noexcept;
+
+template<class _Tp, class _Abi>
+  _Tp hmin(const simd<_Tp, _Abi>&) noexcept;
+template<class _Mp, class _Vp>
+  typename _Vp::value_type hmin(const const_where_expression<_Mp, _Vp>&) noexcept;
+template<class _Tp, class _Abi>
+  _Tp hmax(const simd<_Tp, _Abi>&) noexcept;
+template<class _Mp, class _Vp>
+  typename _Vp::value_type hmax(const const_where_expression<_Mp, _Vp>&) noexcept;
+
+// 9.7.6, Algorithms
+template<class _Tp, class _Abi>
+  simd<_Tp, _Abi>
+    min(const simd<_Tp, _Abi>& __a, const simd<_Tp, _Abi>& __b) noexcept;
+template<class _Tp, class _Abi>
+  simd<_Tp, _Abi>
+    max(const simd<_Tp, _Abi>& __a, const simd<_Tp, _Abi>& __b) noexcept;
+template<class _Tp, class _Abi>
+  pair<simd<_Tp, _Abi>, simd<_Tp, _Abi>>
+    minmax(const simd<_Tp, _Abi>& __a, const simd<_Tp, _Abi>& __b) noexcept;
+template<class _Tp, class _Abi>
+  simd<_Tp, _Abi>
+    clamp(const simd<_Tp, _Abi>& __v,
+          const simd<_Tp, _Abi>& __lo,
+          const simd<_Tp, _Abi>& __hi);
+
+
+// 9.5, Where expression class templates defination
+template<class _Mp, class _Tp> class const_where_expression {
+  const _Mp __mask;   // exposition only
+  _Tp& __data;        // exposition only
 
-template <class _Tp, class _Abi>
-struct is_simd_mask<simd_mask<_Tp, _Abi>> : std::integral_constant<bool, true> {
-};
-
-template <class _Tp>
-struct is_simd_flag_type : std::integral_constant<bool, false> {};
-
-template <>
-struct is_simd_flag_type<element_aligned_tag>
-    : std::integral_constant<bool, true> {};
-
-template <>
-struct is_simd_flag_type<vector_aligned_tag>
-    : std::integral_constant<bool, true> {};
-
-template <size_t _Align>
-struct is_simd_flag_type<overaligned_tag<_Align>>
-    : std::integral_constant<bool, true> {};
-
-template <class _Tp>
-inline constexpr bool is_abi_tag_v = is_abi_tag<_Tp>::value;
-template <class _Tp>
-inline constexpr bool is_simd_v = is_simd<_Tp>::value;
-template <class _Tp>
-inline constexpr bool is_simd_mask_v = is_simd_mask<_Tp>::value;
-template <class _Tp>
-inline constexpr bool is_simd_flag_type_v = is_simd_flag_type<_Tp>::value;
-template <class _Tp, size_t _Np>
-struct abi_for_size {
-  using type = simd_abi::fixed_size<_Np>;
-};
-template <class _Tp, size_t _Np>
-using abi_for_size_t = typename abi_for_size<_Tp, _Np>::type;
-
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-struct simd_size;
-
-template <class _Tp, _StorageKind __kind, int _Np>
-struct simd_size<_Tp, __simd_abi<__kind, _Np>>
-    : std::integral_constant<size_t, _Np> {
-  static_assert(
-      std::is_arithmetic<_Tp>::value &&
-          !std::is_same<__remove_const_t<_Tp>, bool>::value,
-      "Element type should be vectorizable");
-};
-
-// TODO: implement it.
-template <class _Tp, class _Up = typename _Tp::value_type>
-struct memory_alignment;
-
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-inline constexpr size_t simd_size_v = simd_size<_Tp, _Abi>::value;
-
-template <class _Tp, class _Up = typename _Tp::value_type>
-inline constexpr size_t memory_alignment_v = memory_alignment<_Tp, _Up>::value;
-
-// class template simd [simd.class]
-template <class _Tp>
-using native_simd = simd<_Tp, simd_abi::native<_Tp>>;
-template <class _Tp, int _Np>
-using fixed_size_simd = simd<_Tp, simd_abi::fixed_size<_Np>>;
-
-// class template simd_mask [simd.mask.class]
-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>>;
-
-// casts [simd.casts]
-template <class _Tp>
-struct __static_simd_cast_traits {
-  template <class _Up, class _Abi>
-  static simd<_Tp, _Abi> __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp, class _NewAbi>
-struct __static_simd_cast_traits<simd<_Tp, _NewAbi>> {
-  template <class _Up, class _Abi>
-  static typename std::enable_if<simd<_Up, _Abi>::size() ==
-                                     simd<_Tp, _NewAbi>::size(),
-                                 simd<_Tp, _NewAbi>>::type
-  __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp>
-struct __simd_cast_traits {
-  template <class _Up, class _Abi>
-  static typename std::enable_if<
-      __is_non_narrowing_arithmetic_convertible<_Up, _Tp>(),
-      simd<_Tp, _Abi>>::type
-  __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp, class _NewAbi>
-struct __simd_cast_traits<simd<_Tp, _NewAbi>> {
-  template <class _Up, class _Abi>
-  static typename std::enable_if<
-      __is_non_narrowing_arithmetic_convertible<_Up, _Tp>() &&
-          simd<_Up, _Abi>::size() == simd<_Tp, _NewAbi>::size(),
-      simd<_Tp, _NewAbi>>::type
-  __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp, class _Up, class _Abi>
-_LIBCPP_HIDE_FROM_ABI auto simd_cast(const simd<_Up, _Abi>& __v)
-    -> decltype(__simd_cast_traits<_Tp>::__apply(__v)) {
-  return __simd_cast_traits<_Tp>::__apply(__v);
-}
-
-template <class _Tp, class _Up, class _Abi>
-_LIBCPP_HIDE_FROM_ABI auto static_simd_cast(const simd<_Up, _Abi>& __v)
-    -> decltype(__static_simd_cast_traits<_Tp>::__apply(__v)) {
-  return __static_simd_cast_traits<_Tp>::__apply(__v);
-}
-
-template <class _Tp, class _Abi>
-fixed_size_simd<_Tp, simd_size<_Tp, _Abi>::value>
-to_fixed_size(const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-fixed_size_simd_mask<_Tp, simd_size<_Tp, _Abi>::value>
-to_fixed_size(const simd_mask<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, size_t _Np>
-native_simd<_Tp> to_native(const fixed_size_simd<_Tp, _Np>&) noexcept;
-
-template <class _Tp, size_t _Np>
-native_simd_mask<_Tp> to_native(const fixed_size_simd_mask<_Tp, _Np>&) noexcept;
-
-template <class _Tp, size_t _Np>
-simd<_Tp> to_compatible(const fixed_size_simd<_Tp, _Np>&) noexcept;
-
-template <class _Tp, size_t _Np>
-simd_mask<_Tp> to_compatible(const fixed_size_simd_mask<_Tp, _Np>&) noexcept;
-
-template <size_t... __sizes, class _Tp, class _Abi>
-tuple<simd<_Tp, abi_for_size_t<_Tp, __sizes>>...> split(const simd<_Tp, _Abi>&);
-
-template <size_t... __sizes, class _Tp, class _Abi>
-tuple<simd_mask<_Tp, abi_for_size_t<_Tp, __sizes>>...>
-split(const simd_mask<_Tp, _Abi>&);
-
-template <class _SimdType, class _Abi>
-array<_SimdType, simd_size<typename _SimdType::value_type, _Abi>::value /
-                     _SimdType::size()>
-split(const simd<typename _SimdType::value_type, _Abi>&);
-
-template <class _SimdType, class _Abi>
-array<_SimdType, simd_size<typename _SimdType::value_type, _Abi>::value /
-                     _SimdType::size()>
-split(const simd_mask<typename _SimdType::value_type, _Abi>&);
-
-template <class _Tp, class... _Abis>
-simd<_Tp, abi_for_size_t<_Tp, experimental::__variadic_sum(simd_size<_Tp, _Abis>::value...)>>
-concat(const simd<_Tp, _Abis>&...);
-
-template <class _Tp, class... _Abis>
-simd_mask<_Tp,
-          abi_for_size_t<_Tp, experimental::__variadic_sum(simd_size<_Tp, _Abis>::value...)>>
-concat(const simd_mask<_Tp, _Abis>&...);
-
-// reductions [simd.mask.reductions]
-template <class _Tp, class _Abi>
-bool all_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-bool any_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-bool none_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-bool some_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-int popcount(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-int find_first_set(const simd_mask<_Tp, _Abi>&);
-template <class _Tp, class _Abi>
-int find_last_set(const simd_mask<_Tp, _Abi>&);
-bool all_of(bool) noexcept;
-bool any_of(bool) noexcept;
-bool none_of(bool) noexcept;
-bool some_of(bool) noexcept;
-int popcount(bool) noexcept;
-int find_first_set(bool) noexcept;
-int find_last_set(bool) noexcept;
-
-// masked assignment [simd.whereexpr]
-template <class _MaskType, class _Tp>
-class const_where_expression;
-template <class _MaskType, class _Tp>
-class where_expression;
-
-// masked assignment [simd.mask.where]
-template <class _Tp, class _Abi>
-where_expression<simd_mask<_Tp, _Abi>, simd<_Tp, _Abi>>
-where(const typename simd<_Tp, _Abi>::mask_type&, simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-const_where_expression<simd_mask<_Tp, _Abi>, const simd<_Tp, _Abi>>
-where(const typename simd<_Tp, _Abi>::mask_type&,
-      const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-where_expression<simd_mask<_Tp, _Abi>, simd_mask<_Tp, _Abi>>
-where(const typename __nodeduce<simd_mask<_Tp, _Abi>>::type&,
-      simd_mask<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-const_where_expression<simd_mask<_Tp, _Abi>, const simd_mask<_Tp, _Abi>>
-where(const typename __nodeduce<simd_mask<_Tp, _Abi>>::type&,
-      const simd_mask<_Tp, _Abi>&) noexcept;
-
-template <class _Tp>
-where_expression<bool, _Tp> where(bool, _Tp&) noexcept;
-
-template <class _Tp>
-const_where_expression<bool, const _Tp> where(bool, const _Tp&) noexcept;
-
-// reductions [simd.reductions]
-template <class _Tp, class _Abi, class _BinaryOp = std::plus<_Tp>>
-_Tp reduce(const simd<_Tp, _Abi>&, _BinaryOp = _BinaryOp());
-
-template <class _MaskType, class _SimdType, class _BinaryOp>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       typename _SimdType::value_type __neutral_element, _BinaryOp);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       plus<typename _SimdType::value_type> = {});
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       multiplies<typename _SimdType::value_type>);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       bit_and<typename _SimdType::value_type>);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       bit_or<typename _SimdType::value_type>);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       bit_xor<typename _SimdType::value_type>);
-
-template <class _Tp, class _Abi>
-_Tp hmin(const simd<_Tp, _Abi>&);
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-hmin(const const_where_expression<_MaskType, _SimdType>&);
-template <class _Tp, class _Abi>
-_Tp hmax(const simd<_Tp, _Abi>&);
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-hmax(const const_where_expression<_MaskType, _SimdType>&);
-
-// algorithms [simd.alg]
-template <class _Tp, class _Abi>
-simd<_Tp, _Abi> min(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-simd<_Tp, _Abi> max(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-std::pair<simd<_Tp, _Abi>, simd<_Tp, _Abi>>
-minmax(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-simd<_Tp, _Abi> clamp(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&,
-                      const simd<_Tp, _Abi>&);
-
-// [simd.whereexpr]
-// TODO implement where expressions.
-template <class _MaskType, class _Tp>
-class const_where_expression {
 public:
   const_where_expression(const const_where_expression&) = delete;
   const_where_expression& operator=(const const_where_expression&) = delete;
-  __remove_const_t<_Tp> operator-() const&&;
-  template <class _Up, class _Flags>
-  void copy_to(_Up*, _Flags) const&&;
+
+  _Tp operator-() const && noexcept;
+  _Tp operator+() const && noexcept;
+  _Tp operator~() const && noexcept;
+
+  template<class _Up, class _Flags> void copy_to(_Up* __mem, _Flags) const &&;
 };
 
-template <class _MaskType, class _Tp>
-class where_expression : public const_where_expression<_MaskType, _Tp> {
+template<class _Mp, class _Tp>
+class where_expression : public const_where_expression<_Mp, _Tp> {
 public:
-  where_expression(const where_expression&) = delete;
-  where_expression& operator=(const where_expression&) = delete;
-  template <class _Up>
-  void operator=(_Up&&);
-  template <class _Up>
-  void operator+=(_Up&&);
-  template <class _Up>
-  void operator-=(_Up&&);
-  template <class _Up>
-  void operator*=(_Up&&);
-  template <class _Up>
-  void operator/=(_Up&&);
-  template <class _Up>
-  void operator%=(_Up&&);
-  template <class _Up>
-  void operator&=(_Up&&);
-  template <class _Up>
-  void operator|=(_Up&&);
-  template <class _Up>
-  void operator^=(_Up&&);
-  template <class _Up>
-  void operator<<=(_Up&&);
-  template <class _Up>
-  void operator>>=(_Up&&);
-  void operator++();
-  void operator++(int);
-  void operator--();
-  void operator--(int);
-  template <class _Up, class _Flags>
-  void copy_from(const _Up*, _Flags);
+  template<class _Up> void operator=(_Up&& x) && noexcept;
+  template<class _Up> void operator+=(_Up&& x) && noexcept;
+  template<class _Up> void operator-=(_Up&& x) && noexcept;
+  template<class _Up> void operator*=(_Up&& x) && noexcept;
+  template<class _Up> void operator/=(_Up&& x) && noexcept;
+  template<class _Up> void operator%=(_Up&& x) && noexcept;
+  template<class _Up> void operator&=(_Up&& x) && noexcept;
+  template<class _Up> void operator|=(_Up&& x) && noexcept;
+  template<class _Up> void operator^=(_Up&& x) && noexcept;
+  template<class _Up> void operator<<=(_Up&& x) && noexcept;
+  template<class _Up> void operator>>=(_Up&& x) && noexcept;
+
+  void operator++() && noexcept;
+  void operator++(int) && noexcept;
+  void operator--() && noexcept;
+  void operator--(int) && noexcept;
+
+  template<class _Up, class _Flags> void copy_from(const _Up* __mem, _Flags) &&;
 };
 
-// [simd.class]
-// TODO: implement simd
-template <class _Tp, class _Abi>
-class simd {
+// 9.6, Class template simd defination
+template<class _Tp, class _Abi> class simd {
 public:
   using value_type = _Tp;
-  using reference = __simd_reference<_Tp, _Tp, _Abi>;
+  using reference = __simd_reference<value_type>;
   using mask_type = simd_mask<_Tp, _Abi>;
   using abi_type = _Abi;
 
-  simd() = default;
-  simd(const simd&) = default;
-  simd& operator=(const simd&) = default;
+  static constexpr size_t size() noexcept { return simd_size_v<value_type, abi_type>; };
 
-  static constexpr size_t size() noexcept {
-    return simd_size<_Tp, _Abi>::value;
-  }
+  simd() noexcept = default;
 
-private:
-  __simd_storage<_Tp, _Abi> __s_;
-
-  template <class _Up>
-  static constexpr bool __can_broadcast() {
-    return (std::is_arithmetic<_Up>::value &&
-            __is_non_narrowing_arithmetic_convertible<_Up, _Tp>()) ||
-           (!std::is_arithmetic<_Up>::value &&
-            std::is_convertible<_Up, _Tp>::value) ||
-           std::is_same<__remove_const_t<_Up>, int>::value ||
-           (std::is_same<__remove_const_t<_Up>,
-                         unsigned int>::value &&
-            std::is_unsigned<_Tp>::value);
-  }
+  // 9.6.4, simd constructors
+  template<class _Up, enable_if_t<__can_broadcast<value_type, _Up>(), int> = 0>
+    simd(_Up&& __value) noexcept;
+  template<class _Up> simd(const simd<_Up, simd_abi::fixed_size<size()>>&) noexcept;
+  template<class _Gen, enable_if_t<__can_generate<value_type, _Gen>(make_index_sequence<size()>()), int> = 0>
+    explicit simd(_Gen&& __gen) noexcept;
+  template<class _Up, class _Flags> simd(const _Up* __mem, _Flags);
 
-  template <class _Generator, size_t... __indicies>
-  static constexpr decltype(
-      std::forward_as_tuple(std::declval<_Generator>()(
-          std::integral_constant<size_t, __indicies>())...),
-      bool())
-  __can_generate(std::index_sequence<__indicies...>) {
-    return !experimental::__variadic_sum<bool>(
-        !__can_broadcast<decltype(std::declval<_Generator>()(
-            std::integral_constant<size_t, __indicies>()))>()...);
-  }
+  // 9.6.5, simd copy functions
+  template<class _Up, class _Flags> void copy_from(const _Up* __mem, _Flags);
+  template<class _Up, class _Flags> void copy_to(_Up* __mem, _Flags);
 
-  template <class _Generator>
-  static bool __can_generate(...) {
-    return false;
-  }
-
-  template <class _Generator, size_t... __indicies>
-  void __generator_init(_Generator&& __g, std::index_sequence<__indicies...>) {
-    int __not_used[]{((*this)[__indicies] =
-                          __g(std::integral_constant<size_t, __indicies>()),
-                      0)...};
-    (void)__not_used;
-  }
-
-public:
-  // implicit type conversion constructor
-  template <class _Up,
-            class = typename std::enable_if<
-                std::is_same<_Abi, simd_abi::fixed_size<size()>>::value &&
-                __is_non_narrowing_arithmetic_convertible<_Up, _Tp>()>::type>
-  simd(const simd<_Up, simd_abi::fixed_size<size()>>& __v) {
-    for (size_t __i = 0; __i < size(); __i++) {
-      (*this)[__i] = static_cast<_Tp>(__v[__i]);
-    }
-  }
-
-  // implicit broadcast constructor
-  template <class _Up,
-            class = typename std::enable_if<__can_broadcast<_Up>()>::type>
-  simd(_Up&& __rv) {
-    auto __v = static_cast<_Tp>(__rv);
-    for (size_t __i = 0; __i < size(); __i++) {
-      (*this)[__i] = __v;
-    }
-  }
-
-  // generator constructor
-  template <class _Generator,
-            int = typename std::enable_if<
-                __can_generate<_Generator>(std::make_index_sequence<size()>()),
-                int>::type()>
-  explicit simd(_Generator&& __g) {
-    __generator_init(std::forward<_Generator>(__g),
-                     std::make_index_sequence<size()>());
-  }
-
-  // load constructor
-  template <
-      class _Up, class _Flags,
-      class = typename std::enable_if<__vectorizable<_Up>()>::type,
-      class = typename std::enable_if<is_simd_flag_type<_Flags>::value>::type>
-  simd(const _Up* __buffer, _Flags) {
-    // TODO: optimize for overaligned flags
-    for (size_t __i = 0; __i < size(); __i++) {
-      (*this)[__i] = static_cast<_Tp>(__buffer[__i]);
-    }
-  }
-
-  // loads [simd.load]
-  template <class _Up, class _Flags>
-  typename std::enable_if<__vectorizable<_Up>() &&
-                          is_simd_flag_type<_Flags>::value>::type
-  copy_from(const _Up* __buffer, _Flags) {
-    *this = simd(__buffer, _Flags());
-  }
-
-  // stores [simd.store]
-  template <class _Up, class _Flags>
-  typename std::enable_if<__vectorizable<_Up>() &&
-                          is_simd_flag_type<_Flags>::value>::type
-  copy_to(_Up* __buffer, _Flags) const {
-    // TODO: optimize for overaligned flags
-    for (size_t __i = 0; __i < size(); __i++) {
-      __buffer[__i] = static_cast<_Up>((*this)[__i]);
-    }
-  }
+  // 9.6.6, simd subscript operators
+  reference operator[](size_t);
+  value_type operator[](size_t) const;
 
-  // scalar access [simd.subscr]
-  reference operator[](size_t __i) { return reference(&__s_, __i); }
-
-  value_type operator[](size_t __i) const { return __s_.__get(__i); }
-
-  // unary operators [simd.unary]
-  simd& operator++();
-  simd operator++(int);
-  simd& operator--();
-  simd operator--(int);
-  mask_type operator!() const;
-  simd operator~() const;
-  simd operator+() const;
-  simd operator-() const;
-
-#if 0
-  // binary operators [simd.binary]
-  friend simd operator+(const simd&, const simd&);
-  friend simd operator-(const simd&, const simd&);
-  friend simd operator*(const simd&, const simd&);
-  friend simd operator/(const simd&, const simd&);
-  friend simd operator%(const simd&, const simd&);
-  friend simd operator&(const simd&, const simd&);
-  friend simd operator|(const simd&, const simd&);
-  friend simd operator^(const simd&, const simd&);
-  friend simd operator<<(const simd&, const simd&);
-  friend simd operator>>(const simd&, const simd&);
-  friend simd operator<<(const simd&, int);
-  friend simd operator>>(const simd&, int);
-
-  // compound assignment [simd.cassign]
-  friend simd& operator+=(simd&, const simd&);
-  friend simd& operator-=(simd&, const simd&);
-  friend simd& operator*=(simd&, const simd&);
-  friend simd& operator/=(simd&, const simd&);
-  friend simd& operator%=(simd&, const simd&);
-
-  friend simd& operator&=(simd&, const simd&);
-  friend simd& operator|=(simd&, const simd&);
-  friend simd& operator^=(simd&, const simd&);
-  friend simd& operator<<=(simd&, const simd&);
-  friend simd& operator>>=(simd&, const simd&);
-  friend simd& operator<<=(simd&, int);
-  friend simd& operator>>=(simd&, int);
-
-  // compares [simd.comparison]
-  friend mask_type operator==(const simd&, const simd&);
-  friend mask_type operator!=(const simd&, const simd&);
-  friend mask_type operator>=(const simd&, const simd&);
-  friend mask_type operator<=(const simd&, const simd&);
-  friend mask_type operator>(const simd&, const simd&);
-  friend mask_type operator<(const simd&, const simd&);
-#endif
+  // 9.6.7, simd unary operators
+  simd& operator++() noexcept;
+  simd operator++(int) noexcept;
+  simd& operator--() noexcept;
+  simd operator--(int) noexcept;
+  mask_type operator!() const noexcept;
+  simd operator~() const noexcept;
+  simd operator+() const noexcept;
+  simd operator-() const noexcept;
+
+  // 9.7.1, simd binary operators
+  friend simd operator+(const simd&, const simd&) noexcept;
+  friend simd operator-(const simd&, const simd&) noexcept;
+  friend simd operator*(const simd&, const simd&) noexcept;
+  friend simd operator/(const simd&, const simd&) noexcept;
+  friend simd operator%(const simd&, const simd&) noexcept;
+  friend simd operator&(const simd&, const simd&) noexcept;
+  friend simd operator|(const simd&, const simd&) noexcept;
+  friend simd operator^(const simd&, const simd&) noexcept;
+  friend simd operator<<(const simd&, const simd&) noexcept;
+  friend simd operator>>(const simd&, const simd&) noexcept;
+  friend simd operator<<(const simd&, int) noexcept;
+  friend simd operator>>(const simd&, int) noexcept;
+
+  // 9.7.2, simd compound assignment
+  friend simd& operator+=(simd&, const simd&) noexcept;
+  friend simd& operator-=(simd&, const simd&) noexcept;
+  friend simd& operator*=(simd&, const simd&) noexcept;
+  friend simd& operator/=(simd&, const simd&) noexcept;
+  friend simd& operator%=(simd&, const simd&) noexcept;
+  friend simd& operator&=(simd&, const simd&) noexcept;
+  friend simd& operator|=(simd&, const simd&) noexcept;
+  friend simd& operator^=(simd&, const simd&) noexcept;
+  friend simd& operator<<=(simd&, const simd&) noexcept;
+  friend simd& operator>>=(simd&, const simd&) noexcept;
+  friend simd& operator<<=(simd&, int) noexcept;
+  friend simd& operator>>=(simd&, int) noexcept;
+
+  // 9.7.3, simd compare operators
+  friend mask_type operator==(const simd&, const simd&) noexcept;
+  friend mask_type operator!=(const simd&, const simd&) noexcept;
+  friend mask_type operator>=(const simd&, const simd&) noexcept;
+  friend mask_type operator<=(const simd&, const simd&) noexcept;
+  friend mask_type operator>(const simd&, const simd&) noexcept;
+  friend mask_type operator<(const simd&, const simd&) noexcept;
 };
 
-// [simd.mask.class]
-template <class _Tp, class _Abi>
-// TODO: implement simd_mask
-class simd_mask {
+// 9.8, Class template simd_mask defination
+template<class _Tp, class _Abi> class simd_mask {
 public:
   using value_type = bool;
-  // TODO: this is strawman implementation. Turn it into a proxy type.
-  using reference = bool&;
+  using reference = __simd_reference<value_type>;
   using simd_type = simd<_Tp, _Abi>;
   using abi_type = _Abi;
-  static constexpr size_t size() noexcept;
-  simd_mask() = default;
 
-  // broadcast constructor
-  explicit simd_mask(value_type) noexcept;
+  static constexpr size_t size() noexcept { return simd_type::size(); };
 
-  // implicit type conversion constructor
-  template <class _Up>
-  simd_mask(const simd_mask<_Up, simd_abi::fixed_size<size()>>&) noexcept;
+  simd_mask() noexcept = default;
 
-  // load constructor
-  template <class _Flags>
-  simd_mask(const value_type*, _Flags);
+  // 9.8.3, Constructors
+  explicit simd_mask(value_type) noexcept;
+  template<class _Up>
+    simd_mask(const simd_mask<_Up, simd_abi::fixed_size<size()>>&) noexcept;
+  template<class _Flags> simd_mask(const value_type* __mem, _Flags);
 
-  // loads [simd.mask.copy]
-  template <class _Flags>
-  void copy_from(const value_type*, _Flags);
-  template <class _Flags>
-  void copy_to(value_type*, _Flags) const;
+  // 9.8.4, Copy functions
+  template<class _Flags> void copy_from(const value_type* __mem, _Flags);
+  template<class _Flags> void copy_to(value_type* __mem, _Flags);
 
-  // scalar access [simd.mask.subscr]
+  // 9.8.5, Subscript operators
   reference operator[](size_t);
   value_type operator[](size_t) const;
 
-  // unary operators [simd.mask.unary]
+  // 9.8.6, Unary operators
   simd_mask operator!() const noexcept;
 
-#if 0
-  // simd_mask binary operators [simd.mask.binary]
+  // 9.9.1, Binary operators
   friend simd_mask operator&&(const simd_mask&, const simd_mask&) noexcept;
   friend simd_mask operator||(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator&(const simd_mask&, const simd_mask&)noexcept;
+  friend simd_mask operator&(const simd_mask&, const simd_mask&) noexcept;
   friend simd_mask operator|(const simd_mask&, const simd_mask&) noexcept;
   friend simd_mask operator^(const simd_mask&, const simd_mask&) noexcept;
 
-  // simd_mask compound assignment [simd.mask.cassign]
+  // 9.9.2, Compound assignment
   friend simd_mask& operator&=(simd_mask&, const simd_mask&) noexcept;
   friend simd_mask& operator|=(simd_mask&, const simd_mask&) noexcept;
   friend simd_mask& operator^=(simd_mask&, const simd_mask&) noexcept;
 
-  // simd_mask compares [simd.mask.comparison]
+  // 9.9.3, Comparisons
   friend simd_mask operator==(const simd_mask&, const simd_mask&) noexcept;
   friend simd_mask operator!=(const simd_mask&, const simd_mask&) noexcept;
-#endif
 };
 
-#endif // _LIBCPP_STD_VER >= 17
 
 _LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD
 
+#endif // _LIBCPP_STD_VER >= 17
+
 _LIBCPP_POP_MACROS
 
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
diff --git a/libcxx/test/std/experimental/simd/simd.abi/vector_extension.pass.cpp b/libcxx/test/std/experimental/simd/simd.abi/vector_extension.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.abi/vector_extension.pass.cpp
+++ /dev/null
@@ -1,70 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.abi]
-
-#include <experimental/simd>
-#include <cstdint>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-constexpr inline int reg_width() {
-#if defined(__AVX__)
-  return 32;
-#else
-  return 16;
-#endif
-}
-
-#ifndef _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-static_assert(
-    sizeof(ex::simd<char, ex::__simd_abi<ex::_StorageKind::_VecExt, 1>>) == 1,
-    "");
-static_assert(
-    sizeof(ex::simd<char, ex::__simd_abi<ex::_StorageKind::_VecExt, 2>>) == 2,
-    "");
-static_assert(
-    sizeof(ex::simd<char, ex::__simd_abi<ex::_StorageKind::_VecExt, 3>>) == 4,
-    "");
-static_assert(
-    sizeof(ex::simd<char, ex::__simd_abi<ex::_StorageKind::_VecExt, 12>>) == 16,
-    "");
-static_assert(
-    sizeof(ex::simd<int32_t, ex::__simd_abi<ex::_StorageKind::_VecExt, 3>>) ==
-        16,
-    "");
-static_assert(
-    sizeof(ex::simd<int32_t, ex::__simd_abi<ex::_StorageKind::_VecExt, 5>>) ==
-        32,
-    "");
-static_assert(
-    std::is_same<ex::simd_abi::native<int8_t>,
-                 ex::__simd_abi<ex::_StorageKind::_VecExt, reg_width()>>::value,
-    "");
-#else
-static_assert(
-    std::is_same<ex::simd_abi::native<int8_t>,
-                 ex::__simd_abi<ex::_StorageKind::_Array, reg_width()>>::value,
-    "");
-
-#endif
-
-static_assert(std::is_same<ex::simd_abi::compatible<int8_t>,
-                           ex::__simd_abi<ex::_StorageKind::_Array, 16>>::value,
-              "");
-
-int main(int, char**) {
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.access/default.pass.cpp b/libcxx/test/std/experimental/simd/simd.access/default.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.access/default.pass.cpp
+++ /dev/null
@@ -1,220 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// scalar access [simd.subscr]
-// reference operator[](size_t);
-// value_type operator[](size_t) const;
-
-#include <experimental/simd>
-#include <cassert>
-#include <cstdint>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-template <typename SimdType>
-void test_access() {
-  {
-    SimdType a(42), b(4);
-    static_assert(std::is_convertible<decltype(a[0]), int8_t>::value, "");
-
-    assert(a[0] == 42);
-    assert(!a[0] == !42);
-    assert(~a[0] == ~42);
-    assert(+a[0] == +42);
-    assert(-a[0] == -42);
-    assert(a[0] + b[0] == 42 + 4);
-    assert(a[0] - b[0] == 42 - 4);
-    assert(a[0] * b[0] == 42 * 4);
-    assert(a[0] / b[0] == 42 / 4);
-    assert(a[0] % b[0] == 42 % 4);
-    assert(a[0] << b[0] == (42 << 4));
-    assert(a[0] >> b[0] == (42 >> 4));
-    assert((a[0] < b[0]) == false);
-    assert((a[0] <= b[0]) == false);
-    assert((a[0] > b[0]) == true);
-    assert((a[0] >= b[0]) == true);
-    assert((a[0] == b[0]) == false);
-    assert((a[0] != b[0]) == true);
-    assert((a[0] & b[0]) == (42 & 4));
-    assert((a[0] | b[0]) == (42 | 4));
-    assert((a[0] ^ b[0]) == (42 ^ 4));
-    assert((a[0] && b[0]) == true);
-    assert((a[0] || b[0]) == true);
-
-    {
-      auto c = a;
-      ++c[0];
-      assert(c[0] == 42 + 1);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      auto ret = c[0]++;
-      assert(ret == 42);
-      assert(c[0] == 42 + 1);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      --c[0];
-      assert(c[0] == 42 - 1);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      auto ret = c[0]--;
-      assert(ret == 42);
-      assert(c[0] == 42 - 1);
-      assert(c[1] == 42);
-    }
-
-    {
-      auto c = a;
-      c[0] += b[0];
-      assert(c[0] == 42 + 4);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] -= b[0];
-      assert(c[0] == 42 - 4);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] *= b[0];
-      assert(c[0] == 42 * 4);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] /= b[0];
-      assert(c[0] == 42 / 4);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] %= b[0];
-      assert(c[0] == 42 % 4);
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] >>= b[0];
-      assert(c[0] == (42 >> 4));
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] <<= b[0];
-      assert(c[0] == (42 << 4));
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] &= b[0];
-      assert(c[0] == (42 & 4));
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] |= b[0];
-      assert(c[0] == (42 | 4));
-      assert(c[1] == 42);
-    }
-    {
-      auto c = a;
-      c[0] ^= b[0];
-      assert(c[0] == (42 ^ 4));
-      assert(c[1] == 42);
-    }
-
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] += a[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] -= a[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] *= a[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] /= a[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] %= a[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] >>= b[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] <<= b[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] &= a[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] |= a[0]));
-    }
-    {
-      auto c = a;
-      (void)(a[0] + (c[0] ^= a[0]));
-    }
-  }
-  {
-    const SimdType a(42);
-    const SimdType b(4);
-    static_assert(std::is_same<decltype(a[0]), int>::value, "");
-
-    assert(a[0] == 42);
-    assert(!a[0] == !42);
-    assert(~a[0] == ~42);
-    assert(+a[0] == +42);
-    assert(-a[0] == -42);
-    assert(a[0] + b[0] == 42 + 4);
-    assert(a[0] - b[0] == 42 - 4);
-    assert(a[0] * b[0] == 42 * 4);
-    assert(a[0] / b[0] == 42 / 4);
-    assert(a[0] % b[0] == 42 % 4);
-    assert(a[0] << b[0] == (42 << 4));
-    assert(a[0] >> b[0] == (42 >> 4));
-    assert((a[0] < b[0]) == false);
-    assert((a[0] <= b[0]) == false);
-    assert((a[0] > b[0]) == true);
-    assert((a[0] >= b[0]) == true);
-    assert((a[0] == b[0]) == false);
-    assert((a[0] != b[0]) == true);
-    assert((a[0] & b[0]) == (42 & 4));
-    assert((a[0] | b[0]) == (42 | 4));
-    assert((a[0] ^ b[0]) == (42 ^ 4));
-    assert((a[0] && b[0]) == true);
-    assert((a[0] || b[0]) == true);
-  }
-}
-
-int main(int, char**) {
-  test_access<ex::native_simd<int>>();
-  test_access<ex::fixed_size_simd<int, 4>>();
-
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.casts/simd_cast.pass.cpp b/libcxx/test/std/experimental/simd/simd.casts/simd_cast.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.casts/simd_cast.pass.cpp
+++ /dev/null
@@ -1,49 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.casts]
-// template <class T, class U, class Abi> see below ex::simd_cast<(const
-// ex::simd<U, Abi>&);
-
-#include <experimental/simd>
-#include <cstdint>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-static_assert(
-    std::is_same<decltype(ex::simd_cast<int32_t>(ex::native_simd<int32_t>())),
-                 ex::native_simd<int32_t>>::value,
-    "");
-
-static_assert(std::is_same<decltype(ex::simd_cast<int64_t>(
-                               ex::fixed_size_simd<int32_t, 4>())),
-                           ex::fixed_size_simd<int64_t, 4>>::value,
-              "");
-
-static_assert(
-    std::is_same<decltype(ex::simd_cast<ex::fixed_size_simd<int64_t, 1>>(
-                     ex::simd<int32_t, ex::simd_abi::scalar>())),
-                 ex::fixed_size_simd<int64_t, 1>>::value,
-    "");
-
-static_assert(
-    std::is_same<
-        decltype(ex::simd_cast<ex::simd<int64_t, ex::simd_abi::scalar>>(
-            ex::fixed_size_simd<int32_t, 1>())),
-        ex::simd<int64_t, ex::simd_abi::scalar>>::value,
-    "");
-
-int main(int, char**) {
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.casts/static_simd_cast.pass.cpp b/libcxx/test/std/experimental/simd/simd.casts/static_simd_cast.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.casts/static_simd_cast.pass.cpp
+++ /dev/null
@@ -1,44 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.casts]
-// template <class T, class U, class Abi> see below ex::static_simd_cast<(const
-// ex::simd<U, Abi>&);
-
-#include <experimental/simd>
-#include <cstdint>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-static_assert(
-    std::is_same<decltype(ex::static_simd_cast<float>(ex::native_simd<int>())),
-                 ex::native_simd<float>>::value,
-    "");
-
-static_assert(
-    std::is_same<decltype(ex::static_simd_cast<ex::fixed_size_simd<float, 1>>(
-                     ex::simd<int, ex::simd_abi::scalar>())),
-                 ex::fixed_size_simd<float, 1>>::value,
-    "");
-
-static_assert(
-    std::is_same<
-        decltype(ex::static_simd_cast<ex::simd<float, ex::simd_abi::scalar>>(
-            ex::fixed_size_simd<int, 1>())),
-        ex::simd<float, ex::simd_abi::scalar>>::value,
-    "");
-
-int main(int, char**) {
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.class/simd_width.pass.cpp b/libcxx/test/std/experimental/simd/simd.class/simd_width.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/experimental/simd/simd.class/simd_width.pass.cpp
@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <experimental/simd>
+//
+// [simd.class]
+// static constexpr size_t size() noexcept;
+
+#include "../test_utils.h"
+#include <experimental/simd>
+
+namespace ex = std::experimental::parallelism_v2;
+struct CheckSimdWidth {
+  template <class _Tp, class SimdAbi>
+  void operator()() {
+    const ex::simd<_Tp, SimdAbi> origin_simd{};
+    static_assert(origin_simd.size() == ex::simd_size_v<_Tp, SimdAbi>);
+  }
+};
+template <class F, std::size_t _Np, class _Tp>
+void test_simd_abi() {}
+template <class F, std::size_t _Np, class _Tp, class SimdAbi, class... SimdAbis>
+void test_simd_abi() {
+  F{}.template operator()<_Tp, SimdAbi>();
+  test_simd_abi<F, _Np, _Tp, SimdAbis...>();
+}
+
+int main(int, char**) {
+  test_all_simd_abi<CheckSimdWidth>();
+  return 0;
+}
diff --git a/libcxx/test/std/experimental/simd/simd.cons/broadcast.pass.cpp b/libcxx/test/std/experimental/simd/simd.cons/broadcast.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.cons/broadcast.pass.cpp
+++ /dev/null
@@ -1,87 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.class]
-// template <class U> simd(U&& value);
-
-#include <experimental/simd>
-#include <cstdint>
-#include <cassert>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-template <class T, class... Args>
-auto not_supported_native_simd_ctor(Args&&... args)
-    -> decltype(ex::native_simd<T>(std::forward<Args>(args)...),
-                void()) = delete;
-
-template <class T>
-void not_supported_native_simd_ctor(...) {}
-
-template <class T, class... Args>
-auto supported_native_simd_ctor(Args&&... args)
-    -> decltype(ex::native_simd<T>(std::forward<Args>(args)...), void()) {}
-
-template <class T>
-void supported_native_simd_ctor(...) = delete;
-
-void compile_narrowing_conversion() {
-  supported_native_simd_ctor<int8_t>(3);
-  supported_native_simd_ctor<int16_t>(3);
-  supported_native_simd_ctor<int32_t>(3);
-  supported_native_simd_ctor<int64_t>(3);
-  supported_native_simd_ctor<uint8_t>(3);
-  supported_native_simd_ctor<uint16_t>(3);
-  supported_native_simd_ctor<uint32_t>(3);
-  supported_native_simd_ctor<uint64_t>(3);
-  supported_native_simd_ctor<float>(3.f);
-  supported_native_simd_ctor<double>(3.);
-  supported_native_simd_ctor<long double>(3.);
-
-  not_supported_native_simd_ctor<float>(3.);
-  not_supported_native_simd_ctor<int8_t>(long(3));
-  not_supported_native_simd_ctor<float>(long(3));
-  not_supported_native_simd_ctor<int>(3.);
-}
-
-void compile_convertible() {
-  struct ConvertibleToInt {
-    operator int64_t() const;
-  };
-  supported_native_simd_ctor<int64_t>(ConvertibleToInt());
-
-  struct NotConvertibleToInt {};
-  not_supported_native_simd_ctor<int64_t>(NotConvertibleToInt());
-}
-
-void compile_unsigned() {
-  not_supported_native_simd_ctor<int>(3u);
-  supported_native_simd_ctor<uint16_t>(3u);
-}
-
-template <typename SimdType>
-void test_broadcast() {
-  SimdType a(3);
-  for (size_t i = 0; i < a.size(); i++) {
-    assert(a[i] == 3);
-  }
-}
-
-int main(int, char**) {
-  test_broadcast<ex::native_simd<int>>();
-  test_broadcast<ex::fixed_size_simd<int, 4>>();
-  test_broadcast<ex::fixed_size_simd<int, 15>>();
-
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.cons/default.pass.cpp b/libcxx/test/std/experimental/simd/simd.cons/default.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.cons/default.pass.cpp
+++ /dev/null
@@ -1,31 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.class]
-// simd() = default;
-
-#include <cstdint>
-#include <experimental/simd>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-int main(int, char**) {
-  static_assert(ex::native_simd<int32_t>().size() > 0, "");
-  static_assert(ex::fixed_size_simd<int32_t, 4>().size() == 4, "");
-  static_assert(ex::fixed_size_simd<int32_t, 5>().size() == 5, "");
-  static_assert(ex::fixed_size_simd<int32_t, 1>().size() == 1, "");
-  static_assert(ex::fixed_size_simd<char, 32>().size() == 32, "");
-
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.cons/generator.pass.cpp b/libcxx/test/std/experimental/simd/simd.cons/generator.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.cons/generator.pass.cpp
+++ /dev/null
@@ -1,92 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.class]
-// template <class G> explicit simd(G&& gen);
-
-#include <experimental/simd>
-#include <cstdint>
-#include <cassert>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-template <class T, class... Args>
-auto not_supported_simd128_ctor(Args&&... args) -> decltype(
-    ex::fixed_size_simd<T, 16 / sizeof(T)>(std::forward<Args>(args)...),
-    void()) = delete;
-
-template <class T>
-void not_supported_simd128_ctor(...) {}
-
-template <class T, class... Args>
-auto supported_simd128_ctor(Args&&... args) -> decltype(
-    ex::fixed_size_simd<T, 16 / sizeof(T)>(std::forward<Args>(args)...),
-    void()) {}
-
-template <class T>
-void supported_simd128_ctor(...) = delete;
-
-struct identity {
-  template <size_t value>
-  int operator()(std::integral_constant<size_t, value>) const {
-    return value;
-  }
-};
-
-void compile_generator() {
-  supported_simd128_ctor<int>(identity());
-  not_supported_simd128_ctor<int>([](int i) { return float(i); });
-  not_supported_simd128_ctor<int>([](intptr_t i) { return (int*)(i); });
-  not_supported_simd128_ctor<int>([](int* i) { return i; });
-}
-
-struct limited_identity {
-  template <size_t value>
-  typename std::conditional<value <= 2, int32_t, int64_t>::type
-  operator()(std::integral_constant<size_t, value>) const {
-    return value;
-  }
-};
-
-void compile_limited_identity() {
-  supported_simd128_ctor<int64_t>(limited_identity());
-  not_supported_simd128_ctor<int32_t>(limited_identity());
-}
-
-template <typename SimdType>
-void test_generator() {
-  {
-    SimdType a([](int i) { return i; });
-    assert(a[0] == 0);
-    assert(a[1] == 1);
-    assert(a[2] == 2);
-    assert(a[3] == 3);
-  }
-  {
-    SimdType a([](int i) { return 2 * i - 1; });
-    assert(a[0] == -1);
-    assert(a[1] == 1);
-    assert(a[2] == 3);
-    assert(a[3] == 5);
-  }
-}
-
-int main(int, char**) {
-  // TODO: adjust the tests when this assertion fails.
-  assert(ex::native_simd<int32_t>::size() >= 4);
-  test_generator<ex::native_simd<int32_t>>();
-  test_generator<ex::fixed_size_simd<int32_t, 4>>();
-
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.cons/load.pass.cpp b/libcxx/test/std/experimental/simd/simd.cons/load.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.cons/load.pass.cpp
+++ /dev/null
@@ -1,120 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.class]
-// template <class U, class Flags> simd(const U* mem, Flags f);
-
-#include <experimental/simd>
-#include <cstdint>
-#include <cassert>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-template <class T, class... Args>
-auto not_supported_native_simd_ctor(Args&&... args)
-    -> decltype(ex::native_simd<T>(std::forward<Args>(args)...),
-                void()) = delete;
-
-template <class T>
-void not_supported_native_simd_ctor(...) {}
-
-template <class T, class... Args>
-auto supported_native_simd_ctor(Args&&... args)
-    -> decltype(ex::native_simd<T>(std::forward<Args>(args)...), void()) {}
-
-template <class T>
-void supported_native_simd_ctor(...) = delete;
-
-void compile_load_ctor() {
-  supported_native_simd_ctor<int>((int*)nullptr, ex::element_aligned_tag());
-  supported_native_simd_ctor<uint32_t>((int*)nullptr,
-                                       ex::element_aligned_tag());
-  supported_native_simd_ctor<double>((float*)nullptr,
-                                     ex::element_aligned_tag());
-  supported_native_simd_ctor<uint16_t>((unsigned int*)nullptr,
-                                       ex::element_aligned_tag());
-  supported_native_simd_ctor<uint32_t>((float*)nullptr,
-                                       ex::element_aligned_tag());
-
-  not_supported_native_simd_ctor<int>((int*)nullptr, int());
-}
-
-template <typename SimdType>
-void test_load_ctor() {
-  alignas(32) int32_t buffer[] = {4, 3, 2, 1};
-  {
-    SimdType a(buffer, ex::element_aligned_tag());
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a(buffer, ex::vector_aligned_tag());
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a(buffer, ex::overaligned_tag<32>());
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-
-  {
-    SimdType a(buffer, ex::element_aligned);
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a(buffer, ex::vector_aligned);
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a(buffer, ex::overaligned<32>);
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-}
-
-template <typename SimdType>
-void test_converting_load_ctor() {
-  float buffer[] = {1., 2., 4., 8.};
-  SimdType a(buffer, ex::element_aligned_tag());
-  assert(a[0] == 1);
-  assert(a[1] == 2);
-  assert(a[2] == 4);
-  assert(a[3] == 8);
-}
-
-int main(int, char**) {
-  // TODO: adjust the tests when this assertion fails.
-  assert(ex::native_simd<int32_t>::size() >= 4);
-  test_load_ctor<ex::native_simd<int32_t>>();
-  test_load_ctor<ex::fixed_size_simd<int32_t, 4>>();
-  test_converting_load_ctor<ex::native_simd<int32_t>>();
-  test_converting_load_ctor<ex::fixed_size_simd<int32_t, 4>>();
-
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.mask.class/simd_mask_width.pass.cpp b/libcxx/test/std/experimental/simd/simd.mask.class/simd_mask_width.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/experimental/simd/simd.mask.class/simd_mask_width.pass.cpp
@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <experimental/simd>
+//
+// [simd.mask.class]
+// static constexpr size_t size() noexcept;
+
+#include "../test_utils.h"
+#include <experimental/simd>
+
+namespace ex = std::experimental::parallelism_v2;
+struct CheckSimdMaskWidth {
+  template <class _Tp, class SimdAbi>
+  void operator()() {
+    const ex::simd_mask<_Tp, SimdAbi> origin_simd_mask{};
+    static_assert(origin_simd_mask.size() == ex::simd_size_v<_Tp, SimdAbi>);
+  }
+};
+template <class F, std::size_t _Np, class _Tp>
+void test_simd_abi() {}
+template <class F, std::size_t _Np, class _Tp, class SimdAbi, class... SimdAbis>
+void test_simd_abi() {
+  F{}.template operator()<_Tp, SimdAbi>();
+  test_simd_abi<F, _Np, _Tp, SimdAbis...>();
+}
+
+int main(int, char**) {
+  test_all_simd_abi<CheckSimdMaskWidth>();
+  return 0;
+}
diff --git a/libcxx/test/std/experimental/simd/simd.mem/load.pass.cpp b/libcxx/test/std/experimental/simd/simd.mem/load.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.mem/load.pass.cpp
+++ /dev/null
@@ -1,124 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// loads [simd.load]
-// template <class U, class Flags> void copy_from(const U* mem, Flags f);
-
-#include <experimental/simd>
-#include <cstdint>
-#include <cassert>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-template <class T, class... Args>
-auto not_supported_load(Args&&... args) -> decltype(
-    std::declval<ex::native_simd<T>>().copy_from(std::forward<Args>(args)...),
-    void()) = delete;
-
-template <class T>
-void not_supported_load(...) {}
-
-template <class T, class... Args>
-auto supported_load(Args&&... args) -> decltype(
-    std::declval<ex::native_simd<T>>().copy_from(std::forward<Args>(args)...),
-    void()) {}
-
-template <class T>
-void supported_load(...) = delete;
-
-void compile_load() {
-  supported_load<int>((int*)nullptr, ex::element_aligned_tag());
-  supported_load<uint32_t>((int*)nullptr, ex::element_aligned_tag());
-  supported_load<double>((float*)nullptr, ex::element_aligned_tag());
-  supported_load<uint16_t>((unsigned int*)nullptr, ex::element_aligned_tag());
-  supported_load<uint32_t>((float*)nullptr, ex::element_aligned_tag());
-
-  not_supported_load<int>((int*)nullptr, int());
-}
-
-template <typename SimdType>
-void test_load() {
-  alignas(32) int32_t buffer[] = {4, 3, 2, 1};
-  {
-    SimdType a;
-    a.copy_from(buffer, ex::element_aligned_tag());
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a;
-    a.copy_from(buffer, ex::vector_aligned_tag());
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a;
-    a.copy_from(buffer, ex::overaligned_tag<32>());
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-
-  {
-    SimdType a;
-    a.copy_from(buffer, ex::element_aligned);
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a;
-    a.copy_from(buffer, ex::vector_aligned);
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-  {
-    SimdType a;
-    a.copy_from(buffer, ex::overaligned<32>);
-    assert(a[0] == 4);
-    assert(a[1] == 3);
-    assert(a[2] == 2);
-    assert(a[3] == 1);
-  }
-}
-
-template <typename SimdType>
-void test_converting_load() {
-  float buffer[] = {1., 2., 4., 8.};
-  SimdType a;
-  a.copy_from(buffer, ex::element_aligned_tag());
-  assert(a[0] == 1);
-  assert(a[1] == 2);
-  assert(a[2] == 4);
-  assert(a[3] == 8);
-}
-
-int main(int, char**) {
-  // TODO: adjust the tests when this assertion fails.
-  assert(ex::native_simd<int32_t>::size() >= 4);
-  test_load<ex::native_simd<int32_t>>();
-  test_load<ex::fixed_size_simd<int32_t, 4>>();
-  test_converting_load<ex::native_simd<int32_t>>();
-  test_converting_load<ex::fixed_size_simd<int32_t, 4>>();
-
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.mem/store.pass.cpp b/libcxx/test/std/experimental/simd/simd.mem/store.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.mem/store.pass.cpp
+++ /dev/null
@@ -1,97 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// // stores [simd.store]
-// template <class U, class Flags> void copy_to(U* mem, Flags f) const;
-
-#include <experimental/simd>
-#include <cstdint>
-#include <cassert>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-template <typename SimdType>
-void test_store() {
-  SimdType a([](int i) { return 4 - i; });
-  {
-    alignas(32) int32_t buffer[4] = {0};
-    a.copy_to(buffer, ex::element_aligned_tag());
-    assert(buffer[0] == 4);
-    assert(buffer[1] == 3);
-    assert(buffer[2] == 2);
-    assert(buffer[3] == 1);
-  }
-  {
-    alignas(32) int32_t buffer[4] = {0};
-    a.copy_to(buffer, ex::vector_aligned_tag());
-    assert(buffer[0] == 4);
-    assert(buffer[1] == 3);
-    assert(buffer[2] == 2);
-    assert(buffer[3] == 1);
-  }
-  {
-    alignas(32) int32_t buffer[4] = {0};
-    a.copy_to(buffer, ex::overaligned_tag<32>());
-    assert(buffer[0] == 4);
-    assert(buffer[1] == 3);
-    assert(buffer[2] == 2);
-    assert(buffer[3] == 1);
-  }
-
-  {
-    alignas(32) int32_t buffer[4] = {0};
-    a.copy_to(buffer, ex::element_aligned);
-    assert(buffer[0] == 4);
-    assert(buffer[1] == 3);
-    assert(buffer[2] == 2);
-    assert(buffer[3] == 1);
-  }
-  {
-    alignas(32) int32_t buffer[4] = {0};
-    a.copy_to(buffer, ex::vector_aligned);
-    assert(buffer[0] == 4);
-    assert(buffer[1] == 3);
-    assert(buffer[2] == 2);
-    assert(buffer[3] == 1);
-  }
-  {
-    alignas(32) int32_t buffer[4] = {0};
-    a.copy_to(buffer, ex::overaligned<32>);
-    assert(buffer[0] == 4);
-    assert(buffer[1] == 3);
-    assert(buffer[2] == 2);
-    assert(buffer[3] == 1);
-  }
-}
-
-template <typename SimdType>
-void test_converting_store() {
-  float buffer[4] = {0.};
-  SimdType a([](int i) { return 1 << i; });
-  a.copy_to(buffer, ex::element_aligned_tag());
-  assert(buffer[0] == 1.);
-  assert(buffer[1] == 2.);
-  assert(buffer[2] == 4.);
-  assert(buffer[3] == 8.);
-}
-
-int main(int, char**) {
-  // TODO: adjust the tests when this assertion fails.
-  test_store<ex::native_simd<int32_t>>();
-  test_store<ex::fixed_size_simd<int32_t, 4>>();
-  test_converting_store<ex::native_simd<int32_t>>();
-  test_converting_store<ex::fixed_size_simd<int32_t, 4>>();
-
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.traits/abi_for_size.pass.cpp b/libcxx/test/std/experimental/simd/simd.traits/abi_for_size.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.traits/abi_for_size.pass.cpp
+++ /dev/null
@@ -1,35 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.traits]
-// template <class T, size_t N> struct abi_for_size { using type = see below ;
-// }; template <class T, size_t N> using ex::abi_for_size_t = typename
-// ex::abi_for_size<T, N>::type;
-
-#include <cstdint>
-#include <experimental/simd>
-
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-static_assert(std::is_same<typename ex::abi_for_size<int, 4>::type,
-                           ex::simd_abi::fixed_size<4>>::value,
-              "");
-
-static_assert(std::is_same<ex::abi_for_size_t<int, 4>,
-                           ex::simd_abi::fixed_size<4>>::value,
-              "");
-
-int main(int, char**) {
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.traits/is_abi_tag.pass.cpp b/libcxx/test/std/experimental/simd/simd.traits/is_abi_tag.pass.cpp
--- a/libcxx/test/std/experimental/simd/simd.traits/is_abi_tag.pass.cpp
+++ b/libcxx/test/std/experimental/simd/simd.traits/is_abi_tag.pass.cpp
@@ -12,103 +12,67 @@
 //
 // [simd.traits]
 // template <class T> struct is_abi_tag;
-// template <class T> inline constexpr bool ex::is_abi_tag_v =
-// ex::is_abi_tag<T>::value;
+// template <class T> inline constexpr bool ex::is_abi_tag_v = ex::is_abi_tag<T>::value;
 
+#include "../test_utils.h"
 #include <cstdint>
 #include <experimental/simd>
-#include "test_macros.h"
 
 namespace ex = std::experimental::parallelism_v2;
 
-struct UserType {};
-
-static_assert(ex::is_abi_tag<ex::simd_abi::native<int8_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<int16_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<int32_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<int64_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<uint8_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<uint16_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<uint32_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<uint64_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<float>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::native<double>>::value, "");
-
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<int8_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<int16_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<int32_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<int64_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<uint8_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<uint16_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<uint32_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<uint64_t>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<float>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::compatible<double>>::value, "");
-
-static_assert(ex::is_abi_tag<ex::simd_abi::scalar>::value, "");
-static_assert(
-    !std::is_same<ex::simd_abi::scalar, ex::simd_abi::fixed_size<1>>::value,
-    "");
-
-static_assert(ex::is_abi_tag<ex::simd_abi::fixed_size<1>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::fixed_size<2>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::fixed_size<3>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::fixed_size<4>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::fixed_size<5>>::value, "");
-static_assert(ex::is_abi_tag<ex::simd_abi::fixed_size<32>>::value, "");
-
-static_assert(!ex::is_abi_tag<void>::value, "");
-static_assert(!ex::is_abi_tag<int>::value, "");
-static_assert(!ex::is_abi_tag<float>::value, "");
-static_assert(!ex::is_abi_tag<UserType>::value, "");
-static_assert(!ex::is_abi_tag<ex::simd<int>>::value, "");
-static_assert(!ex::is_abi_tag<ex::simd<float>>::value, "");
-static_assert(!ex::is_abi_tag<ex::simd_mask<int>>::value, "");
-static_assert(!ex::is_abi_tag<ex::simd_mask<float>>::value, "");
-
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<int8_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<int16_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<int32_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<int64_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<uint8_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<uint16_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<uint32_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<uint64_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<float>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::native<double>>, "");
-
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<int8_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<int16_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<int32_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<int64_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<uint8_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<uint16_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<uint32_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<uint64_t>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<float>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::compatible<double>>, "");
-
-static_assert(ex::is_abi_tag_v<ex::simd_abi::scalar>, "");
-static_assert(
-    !std::is_same<ex::simd_abi::scalar, ex::simd_abi::fixed_size<1>>::value,
-    "");
-
-static_assert(ex::is_abi_tag_v<ex::simd_abi::fixed_size<1>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::fixed_size<2>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::fixed_size<3>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::fixed_size<4>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::fixed_size<5>>, "");
-static_assert(ex::is_abi_tag_v<ex::simd_abi::fixed_size<32>>, "");
-
-static_assert(!ex::is_abi_tag_v<void>, "");
-static_assert(!ex::is_abi_tag_v<int>, "");
-static_assert(!ex::is_abi_tag_v<float>, "");
-static_assert(!ex::is_abi_tag_v<UserType>, "");
-static_assert(!ex::is_abi_tag_v<ex::simd<int>>, "");
-static_assert(!ex::is_abi_tag_v<ex::simd<float>>, "");
-static_assert(!ex::is_abi_tag_v<ex::simd_mask<int>>, "");
-static_assert(!ex::is_abi_tag_v<ex::simd_mask<float>>, "");
+struct CheckIsAbiTagTrue {
+  template <class _Tp>
+  void operator()() {
+    static_assert(_Tp::value);
+  }
+};
+
+struct CheckIsAbiTagFalse {
+  template <class _Tp>
+  void operator()() {
+    static_assert(!_Tp::value);
+  }
+};
+
+struct CheckIsAbiTagVTrue {
+  template <bool _Tp>
+  void operator()() {
+    static_assert(_Tp);
+  }
+};
+
+struct CheckIsAbiTagVFalse {
+  template <bool _Tp>
+  void operator()() {
+    static_assert(!_Tp);
+  }
+};
+
+template <class F, std::size_t _Np, class _Tp>
+void test_simd_abi() {}
+template <class F, std::size_t _Np, class _Tp, class SimdAbi, class... SimdAbis>
+void test_simd_abi() {
+  if constexpr (std::is_same<F, CheckIsAbiTagTrue>::value) {
+    F{}.template operator()<ex::is_abi_tag<SimdAbi>>();
+  } else if constexpr (std::is_same<F, CheckIsAbiTagFalse>::value) {
+    F{}.template operator()<ex::is_abi_tag<_Tp>>();
+    F{}.template operator()<ex::is_abi_tag<ex::simd<_Tp, SimdAbi>>>();
+    F{}.template operator()<ex::is_abi_tag<ex::simd_mask<_Tp, SimdAbi>>>();
+  } else if constexpr (std::is_same<F, CheckIsAbiTagVTrue>::value) {
+    F{}.template operator()<ex::is_abi_tag_v<SimdAbi>>();
+  } else {
+    F{}.template operator()<ex::is_abi_tag_v<_Tp>>();
+    F{}.template operator()<ex::is_abi_tag_v<ex::simd<_Tp, SimdAbi>>>();
+    F{}.template operator()<ex::is_abi_tag_v<ex::simd_mask<_Tp, SimdAbi>>>();
+  }
+
+  test_simd_abi<F, _Np, _Tp, SimdAbis...>();
+}
 
 int main(int, char**) {
+  test_all_simd_abi<CheckIsAbiTagTrue>();
+  test_all_simd_abi<CheckIsAbiTagFalse>();
+  test_all_simd_abi<CheckIsAbiTagVTrue>();
+  test_all_simd_abi<CheckIsAbiTagVFalse>();
   return 0;
 }
diff --git a/libcxx/test/std/experimental/simd/simd.traits/is_simd.pass.cpp b/libcxx/test/std/experimental/simd/simd.traits/is_simd.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.traits/is_simd.pass.cpp
+++ /dev/null
@@ -1,130 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.traits]
-// template <class T> struct ex::is_simd;
-// template <class T> inline constexpr bool ex::is_simd_v =
-// ex::is_simd<T>::value;
-
-#include <cstdint>
-#include <experimental/simd>
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-struct UserType {};
-
-static_assert(ex::is_simd<ex::native_simd<int8_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<int16_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<int32_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<int64_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<uint8_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<uint16_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<uint32_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<uint64_t>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<float>>::value, "");
-static_assert(ex::is_simd<ex::native_simd<double>>::value, "");
-
-static_assert(ex::is_simd<ex::fixed_size_simd<int8_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int16_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int32_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int64_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint8_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint16_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint32_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint64_t, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<float, 1>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<double, 1>>::value, "");
-
-static_assert(ex::is_simd<ex::fixed_size_simd<int8_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int16_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int32_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int64_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint8_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint16_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint32_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint64_t, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<float, 3>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<double, 3>>::value, "");
-
-static_assert(ex::is_simd<ex::fixed_size_simd<int8_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int16_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int32_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<int64_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint8_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint16_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint32_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<uint64_t, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<float, 32>>::value, "");
-static_assert(ex::is_simd<ex::fixed_size_simd<double, 32>>::value, "");
-
-static_assert(!ex::is_simd<void>::value, "");
-static_assert(!ex::is_simd<int>::value, "");
-static_assert(!ex::is_simd<float>::value, "");
-static_assert(!ex::is_simd<ex::simd_mask<int>>::value, "");
-static_assert(!ex::is_simd<ex::simd_mask<float>>::value, "");
-static_assert(!ex::is_simd<UserType>::value, "");
-
-static_assert(ex::is_simd_v<ex::native_simd<int8_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<int16_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<int32_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<int64_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<uint8_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<uint16_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<uint32_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<uint64_t>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<float>>, "");
-static_assert(ex::is_simd_v<ex::native_simd<double>>, "");
-
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int8_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int16_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int32_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int64_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint8_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint16_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint32_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint64_t, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<float, 1>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<double, 1>>, "");
-
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int8_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int16_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int32_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int64_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint8_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint16_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint32_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint64_t, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<float, 3>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<double, 3>>, "");
-
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int8_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int16_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int32_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<int64_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint8_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint16_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint32_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<uint64_t, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<float, 32>>, "");
-static_assert(ex::is_simd_v<ex::fixed_size_simd<double, 32>>, "");
-
-static_assert(!ex::is_simd_v<void>, "");
-static_assert(!ex::is_simd_v<int>, "");
-static_assert(!ex::is_simd_v<float>, "");
-static_assert(!ex::is_simd_v<ex::simd_mask<int>>, "");
-static_assert(!ex::is_simd_v<ex::simd_mask<float>>, "");
-static_assert(!ex::is_simd_v<UserType>, "");
-
-int main(int, char**) {
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.traits/is_simd_flag_type.pass.cpp b/libcxx/test/std/experimental/simd/simd.traits/is_simd_flag_type.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.traits/is_simd_flag_type.pass.cpp
+++ /dev/null
@@ -1,52 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.traits]
-// template <class T> struct is_simd_flag_type;
-// template <class T> inline constexpr bool ex::is_simd_flag_type_v =
-// ex::is_simd_flag_type<T>::value;
-
-#include <cstdint>
-#include <experimental/simd>
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-struct UserType {};
-
-static_assert(ex::is_simd_flag_type<ex::element_aligned_tag>::value, "");
-static_assert(ex::is_simd_flag_type<ex::vector_aligned_tag>::value, "");
-static_assert(ex::is_simd_flag_type<ex::overaligned_tag<16>>::value, "");
-static_assert(ex::is_simd_flag_type<ex::overaligned_tag<32>>::value, "");
-
-static_assert(!ex::is_simd_flag_type<void>::value, "");
-static_assert(!ex::is_simd_flag_type<int>::value, "");
-static_assert(!ex::is_simd_flag_type<float>::value, "");
-static_assert(!ex::is_simd_flag_type<UserType>::value, "");
-static_assert(!ex::is_simd_flag_type<ex::simd<int8_t>>::value, "");
-static_assert(!ex::is_simd_flag_type<ex::simd_mask<int8_t>>::value, "");
-
-static_assert(ex::is_simd_flag_type_v<ex::element_aligned_tag>, "");
-static_assert(ex::is_simd_flag_type_v<ex::vector_aligned_tag>, "");
-static_assert(ex::is_simd_flag_type_v<ex::overaligned_tag<16>>, "");
-static_assert(ex::is_simd_flag_type_v<ex::overaligned_tag<32>>, "");
-
-static_assert(!ex::is_simd_flag_type_v<void>, "");
-static_assert(!ex::is_simd_flag_type_v<int>, "");
-static_assert(!ex::is_simd_flag_type_v<float>, "");
-static_assert(!ex::is_simd_flag_type_v<UserType>, "");
-static_assert(!ex::is_simd_flag_type_v<ex::simd<int8_t>>, "");
-static_assert(!ex::is_simd_flag_type_v<ex::simd_mask<int8_t>>, "");
-
-int main(int, char**) {
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.traits/is_simd_mask.pass.cpp b/libcxx/test/std/experimental/simd/simd.traits/is_simd_mask.pass.cpp
deleted file mode 100644
--- a/libcxx/test/std/experimental/simd/simd.traits/is_simd_mask.pass.cpp
+++ /dev/null
@@ -1,153 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++03, c++11, c++14
-
-// <experimental/simd>
-//
-// [simd.traits]
-// template <class T> struct ex::is_simd_mask;
-// template <class T> inline constexpr bool ex::is_simd_mask_v =
-// ex::is_simd_mask<T>::value;
-
-#include <cstdint>
-#include <experimental/simd>
-#include "test_macros.h"
-
-namespace ex = std::experimental::parallelism_v2;
-
-struct UserType {};
-
-static_assert(ex::is_simd_mask<ex::native_simd_mask<int8_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<int16_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<int32_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<int64_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<uint8_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<uint16_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<uint32_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<uint64_t>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<float>>::value, "");
-static_assert(ex::is_simd_mask<ex::native_simd_mask<double>>::value, "");
-
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int8_t, 1>>::value, "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int16_t, 1>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int32_t, 1>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int64_t, 1>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint8_t, 1>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint16_t, 1>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint32_t, 1>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint64_t, 1>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<float, 1>>::value, "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<double, 1>>::value, "");
-
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int8_t, 3>>::value, "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int16_t, 3>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int32_t, 3>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int64_t, 3>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint8_t, 3>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint16_t, 3>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint32_t, 3>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint64_t, 3>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<float, 3>>::value, "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<double, 3>>::value, "");
-
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int8_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int16_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int32_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<int64_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint8_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint16_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint32_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<uint64_t, 32>>::value,
-              "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<float, 32>>::value, "");
-static_assert(ex::is_simd_mask<ex::fixed_size_simd_mask<double, 32>>::value,
-              "");
-
-static_assert(!ex::is_simd_mask<void>::value, "");
-static_assert(!ex::is_simd_mask<int>::value, "");
-static_assert(!ex::is_simd_mask<float>::value, "");
-static_assert(!ex::is_simd_mask<ex::simd<int>>::value, "");
-static_assert(!ex::is_simd_mask<ex::simd<float>>::value, "");
-static_assert(!ex::is_simd_mask<UserType>::value, "");
-
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<int8_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<int16_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<int32_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<int64_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<uint8_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<uint16_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<uint32_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<uint64_t>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<float>>, "");
-static_assert(ex::is_simd_mask_v<ex::native_simd_mask<double>>, "");
-
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int8_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int16_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int32_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int64_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint8_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint16_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint32_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint64_t, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<float, 1>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<double, 1>>, "");
-
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int8_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int16_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int32_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int64_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint8_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint16_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint32_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint64_t, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<float, 3>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<double, 3>>, "");
-
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int8_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int16_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int32_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<int64_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint8_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint16_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint32_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<uint64_t, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<float, 32>>, "");
-static_assert(ex::is_simd_mask_v<ex::fixed_size_simd_mask<double, 32>>, "");
-
-static_assert(!ex::is_simd_mask_v<void>, "");
-static_assert(!ex::is_simd_mask_v<int>, "");
-static_assert(!ex::is_simd_mask_v<float>, "");
-static_assert(!ex::is_simd_mask_v<ex::simd<int>>, "");
-static_assert(!ex::is_simd_mask_v<ex::simd<float>>, "");
-static_assert(!ex::is_simd_mask_v<UserType>, "");
-
-int main(int, char**) {
-  return 0;
-}
diff --git a/libcxx/test/std/experimental/simd/simd.traits/simd_size.pass.cpp b/libcxx/test/std/experimental/simd/simd.traits/simd_size.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/experimental/simd/simd.traits/simd_size.pass.cpp
@@ -0,0 +1,116 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <experimental/simd>
+//
+// [simd.traits]
+//template <class T, class Abi = simd_abi::compatible<T>> struct simd_size;
+//template <class T, class Abi = simd_abi::compatible<T>>
+//inline constexpr size_t ex::simd_size_v = ex::simd_size<T, Abi>::value;
+
+#include "../test_utils.h"
+#include <experimental/simd>
+
+namespace ex = std::experimental::parallelism_v2;
+
+struct CheckSimdSizeDeduce {
+  template <class _Tp, size_t _Np, class SimdAbi = ex::simd_abi::deduce_t<_Tp, _Np>>
+  void operator()() {
+    static_assert(ex::simd_size<_Tp, SimdAbi>::value == _Np);
+  };
+};
+struct CheckSimdSizeVDeduce {
+  template <class _Tp, size_t _Np, class SimdAbi = ex::simd_abi::deduce_t<_Tp, _Np>>
+  void operator()() {
+    static_assert(ex::simd_size_v<_Tp, SimdAbi> == _Np);
+  };
+};
+struct CheckSimdSizeFixedSize {
+  template <class _Tp, size_t _Np, class SimdAbi = ex::simd_abi::fixed_size<_Np>>
+  void operator()() {
+    static_assert(ex::simd_size<_Tp, SimdAbi>::value == _Np);
+  };
+};
+struct CheckSimdSizeVFixedSize {
+  template <class _Tp, size_t _Np, class SimdAbi = ex::simd_abi::fixed_size<_Np>>
+  void operator()() {
+    static_assert(ex::simd_size_v<_Tp, SimdAbi> == _Np);
+  };
+};
+
+struct CheckSimdSizeScalar {
+  template <class _Tp, class SimdAbi = ex::simd_abi::scalar>
+  void operator()() {
+    static_assert(ex::simd_size<_Tp, SimdAbi>::value == 1);
+  };
+};
+struct CheckSimdSizeVScalar {
+  template <class _Tp, class SimdAbi = ex::simd_abi::scalar>
+  void operator()() {
+    static_assert(ex::simd_size_v<_Tp, SimdAbi> == 1);
+  };
+};
+struct CheckSimdSizeCompatible {
+  template <class _Tp, class SimdAbi = ex::simd_abi::compatible<_Tp>>
+  void operator()() {
+    static_assert(ex::simd_size<_Tp, SimdAbi>::value == 16 / sizeof(_Tp));
+  };
+};
+struct CheckSimdSizeVCompatible {
+  template <class _Tp, class SimdAbi = ex::simd_abi::compatible<_Tp>>
+  void operator()() {
+    static_assert(ex::simd_size_v<_Tp, SimdAbi> == 16 / sizeof(_Tp));
+  };
+};
+
+struct CheckSimdSizeNative {
+  template <class _Tp, class SimdAbi = ex::simd_abi::native<_Tp>>
+  void operator()() {
+    static_assert(ex::simd_size<_Tp, SimdAbi>::value == _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES / sizeof(_Tp));
+  };
+};
+struct CheckSimdSizeVNative {
+  template <class _Tp, class SimdAbi = ex::simd_abi::native<_Tp>>
+  void operator()() {
+    static_assert(ex::simd_size_v<_Tp, SimdAbi> == _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES / sizeof(_Tp));
+  };
+};
+
+template <class F, std::size_t _Np, class _Tp>
+void test_simd_abi() {}
+template <class F, std::size_t _Np, class _Tp, class SimdAbi, class... SimdAbis>
+void test_simd_abi() {
+  if constexpr (std::is_same<F, CheckSimdSizeDeduce>::value || std::is_same<F, CheckSimdSizeVDeduce>::value ||
+                std::is_same<F, CheckSimdSizeFixedSize>::value || std::is_same<F, CheckSimdSizeVFixedSize>::value) {
+    F{}.template operator()<_Tp, _Np>();
+  } else {
+    F{}.template operator()<_Tp>();
+  }
+  test_simd_abi<F, _Np, _Tp, SimdAbis...>();
+}
+
+int main(int, char**) {
+  test_all_simd_abi<CheckSimdSizeDeduce>();
+  test_all_simd_abi<CheckSimdSizeVDeduce>();
+
+  test_all_simd_abi<CheckSimdSizeFixedSize>();
+  test_all_simd_abi<CheckSimdSizeVFixedSize>();
+
+  test_all_simd_abi<CheckSimdSizeScalar>();
+  test_all_simd_abi<CheckSimdSizeVScalar>();
+
+  test_all_simd_abi<CheckSimdSizeCompatible>();
+  test_all_simd_abi<CheckSimdSizeVCompatible>();
+
+  test_all_simd_abi<CheckSimdSizeNative>();
+  test_all_simd_abi<CheckSimdSizeVNative>();
+
+  return 0;
+}
diff --git a/libcxx/test/std/experimental/simd/test_utils.h b/libcxx/test/std/experimental/simd/test_utils.h
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/experimental/simd/test_utils.h
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 TEST_UTIL_H
+#define TEST_UTIL_H
+
+#include <cassert>
+#include <experimental/simd>
+
+namespace ex = std::experimental::parallelism_v2;
+
+template <class F, std::size_t _Np, class _Tp, class SimdAbi, class... SimdAbis>
+void test_simd_abi();
+
+template <class F, class _Tp, std::size_t... _Np>
+void test_all_simd_abi(std::integer_sequence<std::size_t, _Np...>) {
+  using namespace ex;
+
+  (test_simd_abi<F,
+                 _Np + 1,
+                 _Tp,
+                 simd_abi::native<_Tp>,
+                 simd_abi::fixed_size<_Np + 1>,
+                 simd_abi::scalar,
+                 simd_abi::compatible<_Tp>,
+                 simd_abi::deduce_t<_Tp, _Np + 1>>(),
+   ...);
+}
+
+template <class F>
+void test_all_simd_abi() {
+  constexpr auto integer_seq_from_make_integer = std::make_integer_sequence<size_t, 31>();
+  test_all_simd_abi<F, long double>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, double>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, float>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, long long>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, unsigned long long>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, long>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, unsigned long>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, int>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, unsigned int>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, short>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, unsigned short>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, wchar_t>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, signed char>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, unsigned char>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, char32_t>(integer_seq_from_make_integer);
+  test_all_simd_abi<F, char16_t>(integer_seq_from_make_integer);
+}
+#endif // TEST_UTIL_H