DPCT1008

Intel® DPC++ Compatibility Tool Developer Guide and Reference

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ID 768918

Date 6/24/2024

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Public

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DPCT1008

Message

<function name> function is not defined in SYCL. This is a hardware-specific feature. Consult with your hardware vendor to find a replacement.

Detailed Help

The clock function call was not replaced, because it is not defined in SYCL*. Replace this hardware-specific feature with the one offered by your hardware vendor.

Suggestions to Fix

Consult with your hardware vendor to find a replacement.

For example, this original CUDA* code:

__global__ void k(clock_t *timer) {
  int tid = threadIdx.x;
  if (tid == 0)
    timer[0] = clock();

  // workload

  __syncthreads();
  if (tid == 0)
    timer[1] = clock();
}

int main() {
  clock_t *dtimer = NULL;
  cudaMalloc((void **)&dtimer, sizeof(clock_t) * 2);
  clock_t timer[2];
  k<<<1, 128>>>(dtimer);
  cudaMemcpy(timer, dtimer, sizeof(clock_t) * 2, cudaMemcpyDeviceToHost);
  cudaFree(dtimer);
  long double time = timer[1] - timer[0];
  return 0;
}

results in the following migrated SYCL code:

#include <sycl/sycl.hpp>
#include <dpct/dpct.hpp>
#include <time.h>
void k(clock_t *timer, sycl::nd_item<3> item_ct1) {
  int tid = item_ct1.get_local_id(2);
  if (tid == 0)
    /*
    DPCT1008:1: clock function is not defined in SYCL. This is a
    hardware-specific feature. Consult with your hardware vendor to find a
    replacement.
    */
    timer[0] = clock();// clock() is used to measure the kernel runtime

  // workload

  item_ct1.barrier();
  if (tid == 0)
    /*
             DPCT1008:2: clock function is not defined in SYCL. This is a
             hardware-specific feature. Consult with your hardware vendor to find a
     replacement.
    */
    timer[1] = clock();
}

int main() {
  dpct::device_ext &dev_ct1 = dpct::get_current_device();
  sycl::queue &q_ct1 = dev_ct1.default_queue();
  clock_t *dtimer = NULL;
  dtimer = sycl::malloc_device<clock_t>(2, q_ct1);
  clock_t timer[2];
  q_ct1.parallel_for(
      sycl::nd_range<3>(sycl::range<3>(1, 1, 128), sycl::range<3>(1, 1, 128)),
      [=](sycl::nd_item<3> item_ct1) {
        k(dtimer, item_ct1);
      });
  q_ct1.memcpy(timer, dtimer, sizeof(clock_t) * 2).wait();
  sycl::free(dtimer, q_ct1);
  long double time = timer[1] - timer[0];
  return 0;
}

which is rewritten to:

#define DPCT_PROFILING_ENABLED
#include <sycl/sycl.hpp>
#include <dpct/dpct.hpp>
#include <time.h>
void k(sycl::nd_item<3> item_ct1) {
  // workload
}

int main() {
  dpct::device_ext &dev_ct1 = dpct::get_current_device();
  sycl::queue &q_ct1 = dev_ct1.default_queue();
  dpct::event_ptr start;
  dpct::event_ptr end;
  start = new sycl::event();
  end = new sycl::event();
  *start = q_ct1.ext_oneapi_submit_barrier();
  q_ct1.parallel_for(
      sycl::nd_range<3>(sycl::range<3>(1, 1, 128), sycl::range<3>(1, 1, 128)),
      [=](sycl::nd_item<3> item_ct1) {
        k(item_ct1);
      });
  *end = q_ct1.ext_oneapi_submit_barrier();
  end->wait_and_throw();
  long double time =
      (end->get_profiling_info<sycl::info::event_profiling::command_end>() -
       start
           ->get_profiling_info<sycl::info::event_profiling::command_start>()) /
      1000000.0f;  return 0;
}

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Intel® DPC++ Compatibility Tool Developer Guide and Reference

DPCT1008

Message

Detailed Help

Suggestions to Fix