solution.cpp

/*
 SYCL Academy (c)

 SYCL Academy is licensed under a Creative Commons
 Attribution-ShareAlike 4.0 International License.

 You should have received a copy of the license along with this
 work.  If not, see <http://creativecommons.org/licenses/by-sa/4.0/>.
*/

#include "../helpers.hpp"
#include <sycl/sycl.hpp>

class kernel_a_1;
class kernel_b_1;
class kernel_a_2;
class kernel_b_2;

int usm_selector(const sycl::device& dev) {
  if (dev.has(sycl::aspect::usm_device_allocations)) {
    if (dev.has(sycl::aspect::gpu))
      return 2;
    return 1;
  }
  return -1;
}

void test_buffer() {
  constexpr size_t dataSize = 1024;

  float in[dataSize], out[dataSize];
  for (int i = 0; i < dataSize; ++i) {
    in[i] = static_cast<float>(i);
    out[i] = 0.0f;
  }

  try {
    auto gpuQueue = sycl::queue { sycl::gpu_selector_v };

    auto bufIn = sycl::buffer { in, sycl::range { dataSize } };
    auto bufInt = sycl::buffer<float> { sycl::range { dataSize } };
    auto bufOut = sycl::buffer<float> { sycl::range { dataSize } };

    bufIn.set_final_data(nullptr);
    bufOut.set_final_data(out);

    gpuQueue.submit([&](sycl::handler& cgh) {
      sycl::accessor accIn { bufIn, cgh, sycl::read_only };
      sycl::accessor accOut { bufInt, cgh, sycl::write_only };

      cgh.parallel_for<kernel_a_1>(
          sycl::range { dataSize },
          [=](sycl::id<1> idx) { accOut[idx] = accIn[idx] * 8.0f; });
    });

    gpuQueue.submit([&](sycl::handler& cgh) {
      sycl::accessor accIn { bufInt, cgh, sycl::read_only };
      sycl::accessor accOut { bufOut, cgh, sycl::write_only };

      cgh.parallel_for<kernel_b_1>(
          sycl::range { dataSize },
          [=](sycl::id<1> idx) { accOut[idx] = accIn[idx] / 2.0f; });
    });

    gpuQueue.wait_and_throw();
  } catch (const sycl::exception& e) {
    std::cout << "Exception caught: " << e.what() << std::endl;
  }

  for (int i = 0; i < dataSize; ++i) {
    SYCLACADEMY_ASSERT(out[i] == i * 4.0f);
  }
}

void test_usm() {
  constexpr size_t dataSize = 1024;

  float in[dataSize], out[dataSize];
  for (int i = 0; i < dataSize; ++i) {
    in[i] = static_cast<float>(i);
    out[i] = 0.0f;
  }

  try {
    auto usmQueue = sycl::queue { usm_selector };

    auto devicePtrIn = sycl::malloc_device<float>(dataSize, usmQueue);
    auto devicePtrInt = sycl::malloc_device<float>(dataSize, usmQueue);
    auto devicePtrOut = sycl::malloc_device<float>(dataSize, usmQueue);

    auto e1 = usmQueue.memcpy(devicePtrIn, in, sizeof(float) * dataSize);

    auto e2 = usmQueue.parallel_for<kernel_a_2>(
        sycl::range { dataSize }, e1, [=](sycl::id<1> idx) {
          auto globalId = idx[0];
          devicePtrInt[globalId] = devicePtrIn[globalId] * 8.0f;
        });

    auto e3 = usmQueue.parallel_for<kernel_b_2>(
        sycl::range { dataSize }, e2, [=](sycl::id<1> idx) {
          auto globalId = idx[0];
          devicePtrOut[globalId] = devicePtrInt[globalId] / 2.0f;
        });

    usmQueue
        .submit([&](sycl::handler& cgh) {
          cgh.depends_on(e3);
          cgh.memcpy(out, devicePtrOut, sizeof(float) * dataSize);
        })
        .wait();

    sycl::free(devicePtrIn, usmQueue);
    sycl::free(devicePtrInt, usmQueue);
    sycl::free(devicePtrOut, usmQueue);

    usmQueue.throw_asynchronous();
  } catch (const sycl::exception& e) {
    std::cout << "Exception caught: " << e.what() << std::endl;
  }

  for (int i = 0; i < dataSize; ++i) {
    SYCLACADEMY_ASSERT(out[i] == i * 4.0f);
  }
}

int main() {
  test_usm();
  test_buffer();
}