DPCT1022

Message

There is no exact match between the maxGridSize and the max_nd_range size. Verify the correctness of the code.

Detailed Help

There is no analogue of the maxGridSize in SYCL*. SYCL nd_ranges can have up to three dimensions, just like grids in CUDA*, but there is no maximum of nd_range size beyond the data type width, which is size_t. The SYCLomatic replaces the maxGridSize with the max_nd_range_size helper, which is initialized to the size_t width.

Suggestions to Fix

Verify the code correctness.

For example, this original CUDA code:

void foo() {
  cudaDeviceProp prop;
  cudaGetDeviceProperties(&prop, 0);
  if (prop.maxGridSize[0] >= TASK_SIZE) {
    // submit the task on one kernel
    ...
  } else {
    // split the task into multi kernels
    ...
  }
}

results in the following migrated SYCL code:

void foo() {
  dpct::device_info prop;
  dpct::dev_mgr::instance().get_device(0).get_device_info(prop);
  /*
  DPCT1022:0: There is no exact match between the maxGridSize and the
  max_nd_range size. Verify the correctness of the code.
  */
  if (prop.get_max_nd_range_size()[0] >= TASK_SIZE) {
    // submit the task on one kernel
    ...
  } else {
    // split the task into multi kernels
    ...
  }
}

which is rewritten to:

void foo() {
  // submit the task on one kernel
  ...
}