is_device_copyable.asciidoc

Test plan for is_device_copyable

This is a test plan for is_device_copyable type trait described in SYCL 2020 sections 4.12.3. is_device_copyable type trait

1. Testing scope

1.1. Device coverage

All of the tests described below are performed only on the default device that is selected on the CTS command line.

1.2. Types coverage

All of the tests described below are performed using typename T which satisfies the requriments of a device copyable type:

• The application defines the trait is_device_copyable_v<T> to true;

• Type T has at least one eligible copy constructor, move constructor, copy assignment operator, or move assignment operator;

• Each eligible copy constructor, move constructor, copy assignment operator, and move assignment operator is public;

• When doing an inter-device transfer of an object of type T, the effect of each eligible copy constructor, move constructor, copy assignment operator, and move assignment operator is the same as a bitwise copy of the object;

• Type T has a public non-deleted destructor;

• The destructor has no effect when executed on the device.

Define a new class of type T with public default constructor, destructor, copy constructor, copy assignment operator and several public members:

class T {
  public:
    T() = default;
    ~T() = default;

    T(int, float, char);
    T(const T&);
    T& operator=(const T&);
    bool operator==(const T&, const T&);

    int a;
    float b;
    char c;
};

2. Tests

2.1. Cpp17UnaryTrait requirements.

is_device_copyable must meet the Cpp17UnaryTrait requirements:

• DefaultConstructible and CopyConstructible. Verify that:

  • std::is_default_constructible_v<is_device_copyable<T>> == true;

  • std::is_copy_constructible_v<is_device_copyable<T>> == true.

• Takes one template type parameter (additional template parameters are optional and allowed). Verify that: std::is_constructible_v<is_device_copyable<T>> == true.

• Publicly and unambiguously derived from a specialization of integral_constant, known as its base characteristic. Verify that
  std::is_base_of_v<std::integral_constant<bool, true>, is_device_copyable<T>> == true.

• The member names of the base characteristic (std::integral_constant<bool, true>) are not hidden and are unambiguously available. Verify that:

  • std::integral_constant<bool, true>::value_type and is_device_copyable<T>::value_type are the same type;

  • std::integral_constant<bool, true>::type and is_device_copyable<T>::type are the same type;

  • Operators std::integral_constant<bool, true>::value_type() and `is_device_copyable<T>::value_type() have the same return type;

  • std::integral_constant<bool, true>::operator() and is_device_copyable<T>::operator() return the same value.

2.2. Specialization for user defined class

Add a specialization for T:

template<>
struct is_device_copyable<T> : std::true_type {}

• Verify that is_device_copyable<T>::value == true;

• Check data transmission:

  • Create an object of type T on the host and pass it to the kernel via a buffer. Validate in the kernel that the object has the expected value.

  • Create an object of type T in the kernel and return it to the host via a buffer. Validate on the host that the object has the expected value.