[libcxx-commits] [libcxx] [libc++] <experimental/simd> Add implicit type conversion constructor for class simd/simd_mask (PR #71132)

[via libcxx-commits]

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@@ -0,0 +1,90 @@
+//===----------------------------------------------------------------------===//
+//
+// 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(const simd<U, simd_abi::fixed_size<size()>>&) noexcept;
+
+#include "../test_utils.h"
+#include <experimental/simd>
+
+namespace ex = std::experimental::parallelism_v2;
+
+template <class T, class SimdAbi, std::size_t array_size>
+struct ConversionHelper {
+  const std::array<T, array_size>& expected_value;
+
+  ConversionHelper(const std::array<T, array_size>& value) : expected_value(value) {}
+
+  template <class U>
+  void operator()() const {
+    if constexpr (!std::is_same_v<U, T> && std::is_same_v<SimdAbi, ex::simd_abi::fixed_size<array_size>> &&
+                  is_non_narrowing_convertible_v<U, T>) {
+      static_assert(noexcept(ex::simd<T, SimdAbi>(ex::simd<U, SimdAbi>{})));
+      ex::simd<U, SimdAbi> origin_simd([](U i) { return i; });
+      ex::simd<T, SimdAbi> simd_from_implicit_conversion(origin_simd);
+      assert_simd_values_equal<array_size>(simd_from_implicit_conversion, expected_value);
+    }
+  }
+};
+
+template <class T, std::size_t>
+struct CheckConversionSimdCtor {
+  template <class SimdAbi>
+  void operator()() {
+    constexpr std::size_t array_size = ex::simd_size_v<T, SimdAbi>;
+    std::array<T, array_size> expected_value;
+    for (size_t i = 0; i < array_size; ++i)
+      expected_value[i] = static_cast<T>(i);
+
+    types::for_each(arithmetic_no_bool_types(), ConversionHelper<T, SimdAbi, array_size>(expected_value));
+  }
+};
+
+template <class U, class T, class SimdAbi = ex::simd_abi::compatible<T>, class = void>
+struct has_conversion_ctor : std::false_type {};
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joy2myself wrote:

Sorry, my previous understanding may not right. The new commit may be what you want.

https://github.com/llvm/llvm-project/pull/71132