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
@@ -0,0 +1,133 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// <experimental/simd>
+//
+// [simd.traits]
+// template <class T> struct is_simd;
+// template <class T> inline constexpr bool is_simd_v = is_simd<T>::value;
+
+#include <cstdint>
+#include <experimental/simd>
+#include "test_macros.h"
+
+using namespace std::experimental::parallelism_v2;
+
+struct UserType {};
+
+static_assert( is_simd<native_simd<int8_t>>::value, "");
+static_assert( is_simd<native_simd<int16_t>>::value, "");
+static_assert( is_simd<native_simd<int32_t>>::value, "");
+static_assert( is_simd<native_simd<int64_t>>::value, "");
+static_assert( is_simd<native_simd<uint8_t>>::value, "");
+static_assert( is_simd<native_simd<uint16_t>>::value, "");
+static_assert( is_simd<native_simd<uint32_t>>::value, "");
+static_assert( is_simd<native_simd<uint64_t>>::value, "");
+static_assert( is_simd<native_simd<float>>::value, "");
+static_assert( is_simd<native_simd<double>>::value, "");
+
+static_assert( is_simd<fixed_size_simd<int8_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<int16_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<int32_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<int64_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint8_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint16_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint32_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint64_t, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<float, 1>>::value, "");
+static_assert( is_simd<fixed_size_simd<double, 1>>::value, "");
+
+static_assert( is_simd<fixed_size_simd<int8_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<int16_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<int32_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<int64_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint8_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint16_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint32_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint64_t, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<float, 3>>::value, "");
+static_assert( is_simd<fixed_size_simd<double, 3>>::value, "");
+
+static_assert( is_simd<fixed_size_simd<int8_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<int16_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<int32_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<int64_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint8_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint16_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint32_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<uint64_t, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<float, 32>>::value, "");
+static_assert( is_simd<fixed_size_simd<double, 32>>::value, "");
+
+static_assert(!is_simd<void>::value, "");
+static_assert(!is_simd<int>::value, "");
+static_assert(!is_simd<float>::value, "");
+static_assert(!is_simd<simd_mask<int>>::value, "");
+static_assert(!is_simd<simd_mask<float>>::value, "");
+static_assert(!is_simd<UserType>::value, "");
+
+#if TEST_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) &&        \
+    !defined(_LIBCPP_HAS_NO_INLINE_VARIABLES)
+
+static_assert( is_simd_v<native_simd<int8_t>>, "");
+static_assert( is_simd_v<native_simd<int16_t>>, "");
+static_assert( is_simd_v<native_simd<int32_t>>, "");
+static_assert( is_simd_v<native_simd<int64_t>>, "");
+static_assert( is_simd_v<native_simd<uint8_t>>, "");
+static_assert( is_simd_v<native_simd<uint16_t>>, "");
+static_assert( is_simd_v<native_simd<uint32_t>>, "");
+static_assert( is_simd_v<native_simd<uint64_t>>, "");
+static_assert( is_simd_v<native_simd<float>>, "");
+static_assert( is_simd_v<native_simd<double>>, "");
+
+static_assert( is_simd_v<fixed_size_simd<int8_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<int16_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<int32_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<int64_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint8_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint16_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint32_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint64_t, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<float, 1>>, "");
+static_assert( is_simd_v<fixed_size_simd<double, 1>>, "");
+
+static_assert( is_simd_v<fixed_size_simd<int8_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<int16_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<int32_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<int64_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint8_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint16_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint32_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint64_t, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<float, 3>>, "");
+static_assert( is_simd_v<fixed_size_simd<double, 3>>, "");
+
+static_assert( is_simd_v<fixed_size_simd<int8_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<int16_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<int32_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<int64_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint8_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint16_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint32_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<uint64_t, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<float, 32>>, "");
+static_assert( is_simd_v<fixed_size_simd<double, 32>>, "");
+
+static_assert(!is_simd_v<void>, "");
+static_assert(!is_simd_v<int>, "");
+static_assert(!is_simd_v<float>, "");
+static_assert(!is_simd_v<simd_mask<int>>, "");
+static_assert(!is_simd_v<simd_mask<float>>, "");
+static_assert(!is_simd_v<UserType>, "");
+
+#endif
+
+int main() {}
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
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// <experimental/simd>
+//
+// [simd.traits]
+// 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;
+
+#include <cstdint>
+#include <experimental/simd>
+#include "test_macros.h"
+
+using namespace std::experimental::parallelism_v2;
+
+struct UserType {};
+
+static_assert( is_simd_flag_type<element_aligned_tag>::value, "");
+static_assert( is_simd_flag_type<vector_aligned_tag>::value, "");
+static_assert( is_simd_flag_type<overaligned_tag<16>>::value, "");
+static_assert( is_simd_flag_type<overaligned_tag<32>>::value, "");
+
+static_assert(!is_simd_flag_type<void>::value, "");
+static_assert(!is_simd_flag_type<int>::value, "");
+static_assert(!is_simd_flag_type<float>::value, "");
+static_assert(!is_simd_flag_type<UserType>::value, "");
+static_assert(!is_simd_flag_type<simd<int8_t>>::value, "");
+static_assert(!is_simd_flag_type<simd_mask<int8_t>>::value, "");
+
+#if TEST_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) &&        \
+    !defined(_LIBCPP_HAS_NO_INLINE_VARIABLES)
+
+static_assert( is_simd_flag_type_v<element_aligned_tag>, "");
+static_assert( is_simd_flag_type_v<vector_aligned_tag>, "");
+static_assert( is_simd_flag_type_v<overaligned_tag<16>>, "");
+static_assert( is_simd_flag_type_v<overaligned_tag<32>>, "");
+
+static_assert(!is_simd_flag_type_v<void>, "");
+static_assert(!is_simd_flag_type_v<int>, "");
+static_assert(!is_simd_flag_type_v<float>, "");
+static_assert(!is_simd_flag_type_v<UserType>, "");
+static_assert(!is_simd_flag_type_v<simd<int8_t>>, "");
+static_assert(!is_simd_flag_type_v<simd_mask<int8_t>>, "");
+
+#endif
+
+int main() {}
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
@@ -0,0 +1,133 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// <experimental/simd>
+//
+// [simd.traits]
+// template <class T> struct is_simd_mask;
+// template <class T> inline constexpr bool is_simd_mask_v = is_simd_mask<T>::value;
+
+#include <cstdint>
+#include <experimental/simd>
+#include "test_macros.h"
+
+using namespace std::experimental::parallelism_v2;
+
+struct UserType {};
+
+static_assert( is_simd_mask<native_simd_mask<int8_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<int16_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<int32_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<int64_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<uint8_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<uint16_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<uint32_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<uint64_t>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<float>>::value, "");
+static_assert( is_simd_mask<native_simd_mask<double>>::value, "");
+
+static_assert( is_simd_mask<fixed_size_simd_mask<int8_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int16_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int32_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int64_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint8_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint16_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint32_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint64_t, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<float, 1>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<double, 1>>::value, "");
+
+static_assert( is_simd_mask<fixed_size_simd_mask<int8_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int16_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int32_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int64_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint8_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint16_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint32_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint64_t, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<float, 3>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<double, 3>>::value, "");
+
+static_assert( is_simd_mask<fixed_size_simd_mask<int8_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int16_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int32_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<int64_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint8_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint16_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint32_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<uint64_t, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<float, 32>>::value, "");
+static_assert( is_simd_mask<fixed_size_simd_mask<double, 32>>::value, "");
+
+static_assert(!is_simd_mask<void>::value, "");
+static_assert(!is_simd_mask<int>::value, "");
+static_assert(!is_simd_mask<float>::value, "");
+static_assert(!is_simd_mask<simd<int>>::value, "");
+static_assert(!is_simd_mask<simd<float>>::value, "");
+static_assert(!is_simd_mask<UserType>::value, "");
+
+#if TEST_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) &&        \
+    !defined(_LIBCPP_HAS_NO_INLINE_VARIABLES)
+
+static_assert( is_simd_mask_v<native_simd_mask<int8_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<int16_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<int32_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<int64_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<uint8_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<uint16_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<uint32_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<uint64_t>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<float>>, "");
+static_assert( is_simd_mask_v<native_simd_mask<double>>, "");
+
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int8_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int16_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int32_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int64_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint8_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint16_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint32_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint64_t, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<float, 1>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<double, 1>>, "");
+
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int8_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int16_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int32_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int64_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint8_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint16_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint32_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint64_t, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<float, 3>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<double, 3>>, "");
+
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int8_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int16_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int32_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<int64_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint8_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint16_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint32_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<uint64_t, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<float, 32>>, "");
+static_assert( is_simd_mask_v<fixed_size_simd_mask<double, 32>>, "");
+
+static_assert(!is_simd_mask_v<void>, "");
+static_assert(!is_simd_mask_v<int>, "");
+static_assert(!is_simd_mask_v<float>, "");
+static_assert(!is_simd_mask_v<simd<int>>, "");
+static_assert(!is_simd_mask_v<simd<float>>, "");
+static_assert(!is_simd_mask_v<UserType>, "");
+
+#endif
+
+int main() {}