[libc++] <experimental/simd> Add copy functions for class simd/simd_mask (#78935)

libcxx/docs/Status/ParallelismProjects.csv

@@ -24,6 +24,7 @@ Section,Description,Dependencies,Assignee,Complete
 | `[parallel.simd.class] <https://wg21.link/N4808>`_, "`simd generate constructor <https://reviews.llvm.org/D159442>`_", None, Yin Zhang, |Complete|
 | `[parallel.simd.class] <https://wg21.link/N4808>`_, "`simd load constructor <https://github.com/llvm/llvm-project/pull/76610>`_", None, Yin Zhang, |Complete|
 | `[parallel.simd.class] <https://wg21.link/N4808>`_, "`simd subscript operators <https://github.com/llvm/llvm-project/pull/68960>`_", None, Yin Zhang, |Complete|
+| `[parallel.simd.class] <https://wg21.link/N4808>`_, "`simd copy functions <https://github.com/llvm/llvm-project/pull/78935>`_", None, Yin Zhang, |Complete|
 | `[parallel.simd.class] <https://wg21.link/N4808>`_, "Class template simd implementation", None, Yin Zhang, |In Progress|
 | `[parallel.simd.nonmembers] <https://wg21.link/N4808>`_, "simd non-member operations", None, Yin Zhang, |In Progress|
 | `[parallel.simd.mask.class] <https://wg21.link/N4808>`_, "`Class template simd_mask declaration and alias <https://reviews.llvm.org/D144362>`_", [parallel.simd.abi], Yin Zhang, |Complete|
@@ -33,5 +34,6 @@ Section,Description,Dependencies,Assignee,Complete
 | `[parallel.simd.mask.class] <https://wg21.link/N4808>`_, "`simd_mask implicit type conversion constructor <https://github.com/llvm/llvm-project/pull/71132>`_", None, Yin Zhang, |Complete|
 | `[parallel.simd.mask.class] <https://wg21.link/N4808>`_, "`simd_mask load constructor <https://github.com/llvm/llvm-project/pull/76610>`_", None, Yin Zhang, |Complete|
 | `[parallel.simd.mask.class] <https://wg21.link/N4808>`_, "`simd_mask subscript operators <https://github.com/llvm/llvm-project/pull/68960>`_", None, Yin Zhang, |Complete|
+| `[parallel.simd.mask.class] <https://wg21.link/N4808>`_, "`simd_mask copy functions <https://github.com/llvm/llvm-project/pull/78935>`_", None, Yin Zhang, |Complete|
 | `[parallel.simd.mask.class] <https://wg21.link/N4808>`_, "Class template simd_mask implementation", None, Yin Zhang, |In Progress|
 | `[parallel.simd.mask.nonmembers] <https://wg21.link/N4808>`_, "simd_mask non-member operations", None, Yin Zhang, |In Progress|

libcxx/include/experimental/__simd/scalar.h

@@ -62,6 +62,11 @@ struct __simd_operations<_Tp, simd_abi::__scalar> {
   static _LIBCPP_HIDE_FROM_ABI void __load(_SimdStorage& __s, const _Up* __mem) noexcept {
     __s.__data = static_cast<_Tp>(__mem[0]);
   }
+
+  template <class _Up>
+  static _LIBCPP_HIDE_FROM_ABI void __store(_SimdStorage __s, _Up* __mem) noexcept {
+    *__mem = static_cast<_Up>(__s.__data);
+  }
 };
 
 template <class _Tp>
@@ -71,6 +76,8 @@ struct __mask_operations<_Tp, simd_abi::__scalar> {
   static _LIBCPP_HIDE_FROM_ABI _MaskStorage __broadcast(bool __v) noexcept { return {__v}; }
 
   static _LIBCPP_HIDE_FROM_ABI void __load(_MaskStorage& __s, const bool* __mem) noexcept { __s.__data = __mem[0]; }
+
+  static _LIBCPP_HIDE_FROM_ABI void __store(_MaskStorage __s, bool* __mem) noexcept { __mem[0] = __s.__data; }
 };
 
 } // namespace parallelism_v2

libcxx/include/experimental/__simd/simd.h

@@ -70,6 +70,17 @@ public:
     _Impl::__load(__s_, _Flags::template __apply<simd>(__mem));
   }
 
+  // copy functions
+  template <class _Up, class _Flags, enable_if_t<__is_vectorizable_v<_Up> && is_simd_flag_type_v<_Flags>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI void copy_from(const _Up* __mem, _Flags) {
+    _Impl::__load(__s_, _Flags::template __apply<simd>(__mem));
+  }
+
+  template <class _Up, class _Flags, enable_if_t<__is_vectorizable_v<_Up> && is_simd_flag_type_v<_Flags>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI void copy_to(_Up* __mem, _Flags) const {
+    _Impl::__store(__s_, _Flags::template __apply<simd>(__mem));
+  }
+
   // scalar access [simd.subscr]
   _LIBCPP_HIDE_FROM_ABI reference operator[](size_t __i) noexcept { return reference(__s_, __i); }
   _LIBCPP_HIDE_FROM_ABI value_type operator[](size_t __i) const noexcept { return __s_.__get(__i); }

libcxx/include/experimental/__simd/simd_mask.h

@@ -58,6 +58,17 @@ public:
     _Impl::__load(__s_, _Flags::template __apply<simd_mask>(__mem));
   }
 
+  // copy functions
+  template <class _Flags, enable_if_t<is_simd_flag_type_v<_Flags>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI void copy_from(const value_type* __mem, _Flags) {
+    _Impl::__load(__s_, _Flags::template __apply<simd_mask>(__mem));
+  }
+
+  template <class _Flags, enable_if_t<is_simd_flag_type_v<_Flags>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI void copy_to(value_type* __mem, _Flags) const {
+    _Impl::__store(__s_, _Flags::template __apply<simd_mask>(__mem));
+  }
+
   // scalar access [simd.mask.subscr]
   _LIBCPP_HIDE_FROM_ABI reference operator[](size_t __i) noexcept { return reference(__s_, __i); }
   _LIBCPP_HIDE_FROM_ABI value_type operator[](size_t __i) const noexcept { return __s_.__get(__i); }

libcxx/include/experimental/__simd/vec_ext.h

@@ -80,6 +80,12 @@ struct __simd_operations<_Tp, simd_abi::__vec_ext<_Np>> {
     for (size_t __i = 0; __i < _Np; __i++)
       __s.__data[__i] = static_cast<_Tp>(__mem[__i]);
   }
+
+  template <class _Up>
+  static _LIBCPP_HIDE_FROM_ABI void __store(_SimdStorage __s, _Up* __mem) noexcept {
+    for (size_t __i = 0; __i < _Np; __i++)
+      __mem[__i] = static_cast<_Up>(__s.__data[__i]);
+  }
 };
 
 template <class _Tp, int _Np>
@@ -99,6 +105,11 @@ struct __mask_operations<_Tp, simd_abi::__vec_ext<_Np>> {
     for (size_t __i = 0; __i < _Np; __i++)
       __s.__data[__i] = experimental::__set_all_bits<_Tp>(__mem[__i]);
   }
+
+  static _LIBCPP_HIDE_FROM_ABI void __store(_MaskStorage __s, bool* __mem) noexcept {
+    for (size_t __i = 0; __i < _Np; __i++)
+      __mem[__i] = static_cast<bool>(__s.__data[__i]);
+  }
 };
 
 } // namespace parallelism_v2

libcxx/test/std/experimental/simd/simd.class/simd_copy.pass.cpp

@@ -0,0 +1,173 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+
+// FIXME: Fatal error with following targets (remove XFAIL when fixed):
+//   Pass-by-value arguments with alignment greater than register width are not supported.
+// XFAIL: target=powerpc{{.*}}-ibm-aix7.2.5.7
+
+// <experimental/simd>
+//
+// [simd.class]
+// template<class U, class Flags> void copy_from(const U* mem, Flags);
+// template<class U, class Flags> void copy_to(U* mem, Flags) const;
+
+#include "../test_utils.h"
+
+namespace ex = std::experimental::parallelism_v2;
+
+template <class T, class SimdAbi, std::size_t array_size>
+struct ElementAlignedCopyFromHelper {
+  template <class U>
+  void operator()() const {
+    U buffer[array_size];
+    for (size_t i = 0; i < array_size; ++i)
+      buffer[i] = static_cast<U>(i);
+    ex::simd<T, SimdAbi> origin_simd;
+    origin_simd.copy_from(buffer, ex::element_aligned_tag());
+    assert_simd_values_equal(origin_simd, buffer);
+  }
+};
+
+template <class T, class SimdAbi, std::size_t array_size>
+struct VectorAlignedCopyFromHelper {
+  template <class U>
+  void operator()() const {
+    alignas(ex::memory_alignment_v<ex::simd<T, SimdAbi>, U>) U buffer[array_size];
+    for (size_t i = 0; i < array_size; ++i)
+      buffer[i] = static_cast<U>(i);
+    ex::simd<T, SimdAbi> origin_simd;
+    origin_simd.copy_from(buffer, ex::vector_aligned_tag());
+    assert_simd_values_equal(origin_simd, buffer);
+  }
+};
+
+template <class T, class SimdAbi, std::size_t array_size>
+struct OveralignedCopyFromHelper {
+  template <class U>
+  void operator()() const {
+    alignas(bit_ceil(sizeof(U) + 1)) U buffer[array_size];
+    for (size_t i = 0; i < array_size; ++i)
+      buffer[i] = static_cast<U>(i);
+    ex::simd<T, SimdAbi> origin_simd;
+    origin_simd.copy_from(buffer, ex::overaligned_tag<bit_ceil(sizeof(U) + 1)>());
+    assert_simd_values_equal(origin_simd, buffer);
+  }
+};
+
+template <class T, std::size_t>
+struct CheckSimdCopyFrom {
+  template <class SimdAbi>
+  void operator()() {
+    constexpr std::size_t array_size = ex::simd_size_v<T, SimdAbi>;
+
+    types::for_each(simd_test_types(), ElementAlignedCopyFromHelper<T, SimdAbi, array_size>());
+    types::for_each(simd_test_types(), VectorAlignedCopyFromHelper<T, SimdAbi, array_size>());
+    types::for_each(simd_test_types(), OveralignedCopyFromHelper<T, SimdAbi, array_size>());
+  }
+};
+
+template <class T, class SimdAbi, std::size_t array_size>
+struct ElementAlignedCopyToHelper {
+  template <class U>
+  void operator()() const {
+    U buffer[array_size];
+    ex::simd<T, SimdAbi> origin_simd([](T i) { return i; });
+    origin_simd.copy_to(buffer, ex::element_aligned_tag());
+    assert_simd_values_equal(origin_simd, buffer);
+  }
+};
+
+template <class T, class SimdAbi, std::size_t array_size>
+struct VectorAlignedCopyToHelper {
+  template <class U>
+  void operator()() const {
+    alignas(ex::memory_alignment_v<ex::simd<T, SimdAbi>, U>) U buffer[array_size];
+    ex::simd<T, SimdAbi> origin_simd([](T i) { return i; });
+    origin_simd.copy_to(buffer, ex::vector_aligned_tag());
+    assert_simd_values_equal(origin_simd, buffer);
+  }
+};
+
+template <class T, class SimdAbi, std::size_t array_size>
+struct OveralignedCopyToHelper {
+  template <class U>
+  void operator()() const {
+    alignas(bit_ceil(sizeof(U) + 1)) U buffer[array_size];
+    ex::simd<T, SimdAbi> origin_simd([](T i) { return i; });
+    origin_simd.copy_to(buffer, ex::overaligned_tag<bit_ceil(sizeof(U) + 1)>());
+    assert_simd_values_equal(origin_simd, buffer);
+  }
+};
+
+template <class T, std::size_t>
+struct CheckSimdCopyTo {
+  template <class SimdAbi>
+  void operator()() {
+    constexpr std::size_t array_size = ex::simd_size_v<T, SimdAbi>;
+
+    types::for_each(simd_test_types(), ElementAlignedCopyToHelper<T, SimdAbi, array_size>());
+    types::for_each(simd_test_types(), VectorAlignedCopyToHelper<T, SimdAbi, array_size>());
+    types::for_each(simd_test_types(), OveralignedCopyToHelper<T, SimdAbi, array_size>());
+  }
+};
+
+template <class U, class T, class Flags, class SimdAbi = ex::simd_abi::compatible<T>, class = void>
+struct has_copy_from : std::false_type {};
+
+template <class U, class T, class Flags, class SimdAbi>
+struct has_copy_from<U,
+                     T,
+                     Flags,
+                     SimdAbi,
+                     std::void_t<decltype(std::declval<ex::simd<T, SimdAbi>>().copy_from(
+                         std::declval<const U*>(), std::declval<Flags>()))>> : std::true_type {};
+
+template <class U, class T, class Flags, class SimdAbi = ex::simd_abi::compatible<T>, class = void>
+struct has_copy_to : std::false_type {};
+
+template <class U, class T, class Flags, class SimdAbi>
+struct has_copy_to<
+    U,
+    T,
+    Flags,
+    SimdAbi,
+    std::void_t<decltype(std::declval<ex::simd<T, SimdAbi>>().copy_to(std::declval<U*>(), std::declval<Flags>()))>>
+    : std::true_type {};
+
+template <class T, std::size_t>
+struct CheckSimdCopyTraits {
+  template <class SimdAbi>
+  void operator()() {
+    // These functions shall not participate in overload resolution unless
+    // is_simd_flag_type_v<Flags> is true, and
+    // U is a vectorizable type.
+    static_assert(has_copy_from<int, T, ex::element_aligned_tag, SimdAbi>::value);
+    static_assert(has_copy_to<int, T, ex::element_aligned_tag, SimdAbi>::value);
+
+    // is_simd_flag_type_v<Flags> is false
+    static_assert(!has_copy_from<int, T, T, SimdAbi>::value);
+    static_assert(!has_copy_to<int, T, T, SimdAbi>::value);
+    static_assert(!has_copy_from<int, T, SimdAbi, SimdAbi>::value);
+    static_assert(!has_copy_to<int, T, SimdAbi, SimdAbi>::value);
+
+    // U is not a vectorizable type.
+    static_assert(!has_copy_from<SimdAbi, T, ex::element_aligned_tag, SimdAbi>::value);
+    static_assert(!has_copy_to<SimdAbi, T, ex::element_aligned_tag, SimdAbi>::value);
+    static_assert(!has_copy_from<ex::element_aligned_tag, T, ex::element_aligned_tag, SimdAbi>::value);
+    static_assert(!has_copy_to<ex::element_aligned_tag, T, ex::element_aligned_tag, SimdAbi>::value);
+  }
+};
+
+int main(int, char**) {
+  test_all_simd_abi<CheckSimdCopyFrom>();
+  test_all_simd_abi<CheckSimdCopyTo>();
+  test_all_simd_abi<CheckSimdCopyTraits>();
+  return 0;
+}

libcxx/test/std/experimental/simd/simd.mask.class/simd_mask_copy.pass.cpp

@@ -0,0 +1,127 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 Flags> void copy_from(const value_type* mem, Flags);
+// template<class Flags> void copy_to(value_type* mem, Flags);
+
+#include "../test_utils.h"
+
+namespace ex = std::experimental::parallelism_v2;
+
+template <class T, std::size_t>
+struct CheckSimdMaskCopyFrom {
+  template <class SimdAbi>
+  void operator()() {
+    constexpr std::size_t array_size = ex::simd_size_v<T, SimdAbi>;
+
+    // element aligned tag
+    constexpr std::size_t element_alignas_size = alignof(bool);
+    alignas(element_alignas_size) bool element_buffer[array_size];
+    for (size_t i = 0; i < array_size; ++i)
+      element_buffer[i] = static_cast<bool>(i % 2);
+    ex::simd_mask<T, SimdAbi> element_mask;
+    element_mask.copy_from(element_buffer, ex::element_aligned_tag());
+    assert_simd_mask_values_equal(element_mask, element_buffer);
+
+    // vector aligned tag
+    constexpr std::size_t vector_alignas_size = ex::memory_alignment_v<ex::simd_mask<T, SimdAbi>>;
+    alignas(vector_alignas_size) bool vector_buffer[array_size];
+    for (size_t i = 0; i < array_size; ++i)
+      vector_buffer[i] = static_cast<bool>(i % 2);
+    ex::simd_mask<T, SimdAbi> vector_mask;
+    vector_mask.copy_from(vector_buffer, ex::vector_aligned_tag());
+    assert_simd_mask_values_equal(vector_mask, vector_buffer);
+
+    // overaligned tag
+    constexpr std::size_t over_alignas_size = bit_ceil(sizeof(bool) + 1);
+    alignas(over_alignas_size) bool overaligned_buffer[array_size];
+    for (size_t i = 0; i < array_size; ++i)
+      overaligned_buffer[i] = static_cast<bool>(i % 2);
+    ex::simd_mask<T, SimdAbi> overaligned_mask;
+    overaligned_mask.copy_from(overaligned_buffer, ex::overaligned_tag<over_alignas_size>());
+    assert_simd_mask_values_equal(overaligned_mask, overaligned_buffer);
+  }
+};
+
+template <class T, std::size_t>
+struct CheckSimdMaskCopyTo {
+  template <class SimdAbi>
+  void operator()() {
+    constexpr std::size_t array_size = ex::simd_size_v<T, SimdAbi>;
+
+    // element aligned tag
+    constexpr std::size_t element_alignas_size = alignof(bool);
+    alignas(element_alignas_size) bool element_buffer[array_size];
+    ex::simd_mask<T, SimdAbi> element_mask(true);
+    element_mask.copy_to(element_buffer, ex::element_aligned_tag());
+    assert_simd_mask_values_equal(element_mask, element_buffer);
+
+    // vector aligned tag
+    constexpr std::size_t vector_alignas_size = ex::memory_alignment_v<ex::simd_mask<T, SimdAbi>>;
+    alignas(vector_alignas_size) bool vector_buffer[array_size];
+    ex::simd_mask<T, SimdAbi> vector_mask(false);
+    vector_mask.copy_to(vector_buffer, ex::vector_aligned_tag());
+    assert_simd_mask_values_equal(vector_mask, vector_buffer);
+
+    // overaligned tag
+    constexpr std::size_t over_alignas_size = bit_ceil(sizeof(bool) + 1);
+    alignas(over_alignas_size) bool overaligned_buffer[array_size];
+    ex::simd_mask<T, SimdAbi> overaligned_mask(true);
+    overaligned_mask.copy_to(overaligned_buffer, ex::overaligned_tag<over_alignas_size>());
+    assert_simd_mask_values_equal(overaligned_mask, overaligned_buffer);
+  }
+};
+
+template <class T, class Flags, class SimdAbi = ex::simd_abi::compatible<T>, class = void>
+struct has_copy_from : std::false_type {};
+
+template <class T, class Flags, class SimdAbi>
+struct has_copy_from<T,
+                     Flags,
+                     SimdAbi,
+                     std::void_t<decltype(std::declval<ex::simd_mask<T, SimdAbi>>().copy_from(
+                         std::declval<const bool*>(), std::declval<Flags>()))>> : std::true_type {};
+
+template <class T, class Flags, class SimdAbi = ex::simd_abi::compatible<T>, class = void>
+struct has_copy_to : std::false_type {};
+
+template <class T, class Flags, class SimdAbi>
+struct has_copy_to<T,
+                   Flags,
+                   SimdAbi,
+                   std::void_t<decltype(std::declval<ex::simd_mask<T, SimdAbi>>().copy_to(
+                       std::declval<bool*>(), std::declval<Flags>()))>> : std::true_type {};
+
+template <class T, std::size_t>
+struct CheckSimdMaskCopyTraits {
+  template <class SimdAbi>
+  void operator()() {
+    // These functions shall not participate in overload resolution unless
+    // is_simd_flag_type_v<Flags> is true
+    static_assert(has_copy_from<T, ex::element_aligned_tag, SimdAbi>::value);
+    static_assert(has_copy_to<T, ex::element_aligned_tag, SimdAbi>::value);
+
+    // is_simd_flag_type_v<Flags> is false
+    static_assert(!has_copy_from<T, T, SimdAbi>::value);
+    static_assert(!has_copy_to<T, T, SimdAbi>::value);
+    static_assert(!has_copy_from<T, SimdAbi, SimdAbi>::value);
+    static_assert(!has_copy_to<T, SimdAbi, SimdAbi>::value);
+  }
+};
+
+int main(int, char**) {
+  test_all_simd_abi<CheckSimdMaskCopyFrom>();
+  test_all_simd_abi<CheckSimdMaskCopyTo>();
+  test_all_simd_abi<CheckSimdMaskCopyTraits>();
+  return 0;
+}