Share via

unsupported_feature exception of C++ AMP

  • Article

This blog post assumes you have read the introduction to C++ AMP exceptions.

An instance of the unsupported_feature exception type is thrown on invoking a parallel_for_each/ allocating an object on an accelerator which doesn’t support certain features needed for the execution to proceed.The table below lists the common scenarios that result in unsupported_feature exception.

Scenario

Exception Message

Code Snippet

Texture object creation on CPU accelerator

Feature not supported on cpu_accelerator

accelerator a(accelerator::cpu_accelerator);

accelerator_view av = a.default_view;

concurrency::extent<1> ext(1024);

try

{

   texture<int,1> texInt(ext,av);

}

catch(unsupported_feature& ex)

{

   std::cout<< ex.what() << std::endl;

}

Texture object creation with invalid combination of bits_per_channel and short-vector type

The combination of the short vector type and bits-per-scalar-element for the texture is not supported.

accelerator a;

accelerator_view av = a.default_view;

concurrency::extent<1> ext(1024);

try

{

   texture<float,1> texInt(ext,8,av);

}

catch(unsupported_feature& ex)

{

   std::cout<< ex.what() << std::endl;

}

Read and write operations on textures not having bits-per-channel of value 32

Both read and write are detected on a texture with bits-per-scalar-element not equal to 32.

try

{

   concurrency::extent<1> ext(10);

   texture<int, 1> tex(ext, 16);

  parallel_for_each(tex.extent, [&](index<1> idx) restrict(amp)

   {

        auto value = tex[idx] + 1;

        tex.set(idx, value);

    });

}

catch(unsupported_feature& ex)

{

   std::cout<< ex.what() << std::endl;

}

 

My next blog post covers out_of_memory exception.