tidl_api/src/ocl_device.cpp

   1 /******************************************************************************
   2  * Copyright (c) 2017-2018  Texas Instruments Incorporated - http://www.ti.com/
   3  *   All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *     * Redistributions of source code must retain the above copyright
   8  *       notice, this list of conditions and the following disclaimer.
   9  *     * Redistributions in binary form must reproduce the above copyright
  10  *       notice, this list of conditions and the following disclaimer in the
  11  *       documentation and/or other materials provided with the distribution.
  12  *     * Neither the name of Texas Instruments Incorporated nor the
  13  *       names of its contributors may be used to endorse or promote products
  14  *       derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  26  * THE POSSIBILITY OF SUCH DAMAGE.
  27  *****************************************************************************/
  28
  29
  30 #include <cstdlib>
  31 #include <cassert>
  32 using std::size_t;
  33
  34 #include <iostream>
  35
  36 #include "ocl_device.h"
  37 #include "ocl_util.h"
  38 #include "trace.h"
  39 #include "../dsp/ocl_wrapper.dsp_h"
  40
  41 using namespace tidl;
  42
  43 static const char* error2string(cl_int err);
  44 static void        errorCheck(cl_int ret, int line);
  45
  46 Device::Device(cl_device_type t, const DeviceIds& ids):
  47                 device_type_m(t), device_ids_m(ids)
  48 {
  49     TRACE::print("\tOCL Device: %s created\n",
  50               device_type_m == CL_DEVICE_TYPE_ACCELERATOR ? "DSP" :
  51               device_type_m == CL_DEVICE_TYPE_CUSTOM ? "EVE" : "Unknown");
  52
  53     for (int i = 0; i < MAX_DEVICES; i++)
  54         queue_m[i] = nullptr;
  55
  56 }
  57
  58 DspDevice::DspDevice(const DeviceIds& ids, const std::string &binary_filename):
  59               Device(CL_DEVICE_TYPE_ACCELERATOR, ids)
  60 {
  61     cl_uint num_devices_found;
  62     cl_device_id device_ids[MAX_DEVICES];
  63
  64     cl_int errcode = clGetDeviceIDs(0,               // platform
  65                              device_type_m,          // device_type
  66                              MAX_DEVICES,            // num_entries
  67                              device_ids,             // devices
  68                              &num_devices_found);    // num_devices
  69     errorCheck(errcode, __LINE__);
  70
  71     if (num_devices_found != 1)
  72         throw Exception("OpenCL DSP device not found",
  73                         __FILE__, __FUNCTION__, __LINE__);
  74
  75     cl_int num_compute_units;
  76     errcode = clGetDeviceInfo(device_ids[0],
  77                               CL_DEVICE_MAX_COMPUTE_UNITS,
  78                               sizeof(num_compute_units),
  79                               &num_compute_units,
  80                               nullptr);
  81
  82     if (num_compute_units == 1)
  83     {
  84         context_m = clCreateContextFromType(0,              // properties
  85                                             device_type_m,  // device_type
  86                                             0,              // pfn_notify
  87                                             0,              // user_data
  88                                             &errcode);
  89         errorCheck(errcode, __LINE__);
  90
  91         // Queue 0 on device 0
  92         queue_m[0] = clCreateCommandQueue(context_m,
  93                                           device_ids[0],
  94                                           CL_QUEUE_PROFILING_ENABLE,
  95                                           &errcode);
  96         errorCheck(errcode, __LINE__);
  97         BuildProgramFromBinary(binary_filename, device_ids, 1);
  98     }
  99     else
 100     {
 101         const cl_uint NUM_SUB_DEVICES = 2;
 102
 103         // Create 2 sub-device's, each consisting of a C66x DSP
 104         cl_device_partition_property properties[3] =
 105                                         { CL_DEVICE_PARTITION_EQUALLY, 1, 0 };
 106
 107         // Query the number of sub-devices that can be created
 108         cl_uint n_sub_devices = 0;
 109         errcode = clCreateSubDevices(device_ids[0],      // in_device
 110                                      properties,         // properties
 111                                      0,                  // num_devices
 112                                      NULL,               // out_devices
 113                                      &n_sub_devices);    // num_devices_ret
 114         errorCheck(errcode, __LINE__);
 115
 116         assert(n_sub_devices == NUM_SUB_DEVICES);
 117
 118         // Create the sub-devices
 119         cl_device_id sub_devices[NUM_SUB_DEVICES] = {0, 0};
 120         errcode = clCreateSubDevices(device_ids[0],        // in_device
 121                                      properties,           // properties
 122                                      n_sub_devices,        // num_devices
 123                                      sub_devices,          // out_devices
 124                                      nullptr);             // num_devices_ret
 125         errorCheck(errcode, __LINE__);
 126
 127         // Create a context containing the sub-devices
 128         context_m = clCreateContext(NULL,               // properties
 129                                     NUM_SUB_DEVICES,    // num_devices
 130                                     sub_devices,        // devices
 131                                     NULL,               // pfn_notify
 132                                     NULL,               // user_data
 133                                     &errcode);          // errcode_ret
 134         errorCheck(errcode, __LINE__);
 135
 136         // Create queues to each sub-device
 137         for (auto id : device_ids_m)
 138         {
 139             int index = static_cast<int>(id);
 140             queue_m[index] = clCreateCommandQueue(context_m,
 141                                           sub_devices[index],
 142                                           CL_QUEUE_PROFILING_ENABLE,
 143                                           &errcode);
 144             errorCheck(errcode, __LINE__);
 145         }
 146
 147         BuildProgramFromBinary(binary_filename, sub_devices, NUM_SUB_DEVICES);
 148     }
 149
 150     errcode = clGetDeviceInfo(device_ids[0],
 151                                 CL_DEVICE_MAX_CLOCK_FREQUENCY,
 152                                 sizeof(freq_in_mhz_m),
 153                                 &freq_in_mhz_m,
 154                                 nullptr);
 155     errorCheck(errcode, __LINE__);
 156 }
 157
 158
 159 EveDevice::EveDevice(const DeviceIds& ids, const std::string &kernel_names):
 160             Device(CL_DEVICE_TYPE_CUSTOM, ids)
 161 {
 162     cl_uint num_devices_found;
 163     cl_device_id all_device_ids[MAX_DEVICES];
 164
 165     // Find all the OpenCL devices available of the given type
 166     cl_int errcode = clGetDeviceIDs(0,              // platform
 167                              device_type_m,         // device_type
 168                              MAX_DEVICES,           // num_entries
 169                              all_device_ids,        // devices
 170                              &num_devices_found);   // num_devices
 171     errorCheck(errcode, __LINE__);
 172
 173     assert (num_devices_found >= device_ids_m.size());
 174
 175     context_m = clCreateContextFromType(0,              // properties
 176                                         device_type_m,  // device_type
 177                                         0,              // pfn_notify
 178                                         0,              // user_data
 179                                         &errcode);
 180     errorCheck(errcode, __LINE__);
 181
 182
 183     // Create command queues to OpenCL devices specified by the
 184     // device_ids_m set.
 185     for (auto id : device_ids_m)
 186     {
 187         int index = static_cast<int>(id);
 188         queue_m[index] = clCreateCommandQueue(context_m,
 189                                       all_device_ids[index],
 190                                       CL_QUEUE_PROFILING_ENABLE|
 191                                       CL_QUEUE_OUT_OF_ORDER_EXEC_MODE_ENABLE,
 192                                       &errcode);
 193         errorCheck(errcode, __LINE__);
 194     }
 195
 196     BuildProgramFromBinary(kernel_names, all_device_ids, device_ids_m.size());
 197
 198     errcode = clGetDeviceInfo(all_device_ids[0],
 199                                 CL_DEVICE_MAX_CLOCK_FREQUENCY,
 200                                 sizeof(freq_in_mhz_m),
 201                                 &freq_in_mhz_m,
 202                                 nullptr);
 203     errorCheck(errcode, __LINE__);
 204 }
 205
 206
 207 bool DspDevice::BuildProgramFromBinary(const std::string &BFN,
 208                                        cl_device_id device_ids[],
 209                                        int num_devices)
 210 {
 211     size_t bin_len = ocl_wrapper_dsp_bin_len;
 212
 213     assert (bin_len != 0);
 214
 215     // Casting to make ocl_read_binary work with clCreateProgramWithBinary
 216     const unsigned char *bin_arrc = reinterpret_cast <const unsigned char *>
 217                                     (ocl_wrapper_dsp_bin);
 218
 219     size_t lengths[num_devices];
 220     for (int i=0; i < num_devices; i++) lengths[i] = bin_len;
 221
 222     const unsigned char* binaries[num_devices];
 223     for (int i=0; i < num_devices; i++) binaries[i] = bin_arrc;
 224
 225     cl_int err;
 226     program_m = clCreateProgramWithBinary(context_m,
 227                                           num_devices,
 228                                           device_ids,          // device_list
 229                                           lengths,
 230                                           binaries,
 231                                           0,                   // binary_status
 232                                           &err);
 233     errorCheck(err, __LINE__);
 234
 235     const char *options = "";
 236     err = clBuildProgram(program_m, num_devices, device_ids, options, 0, 0);
 237     errorCheck(err, __LINE__);
 238
 239     return true;
 240 }
 241
 242 bool EveDevice::BuildProgramFromBinary(const std::string& kernel_names,
 243                                        cl_device_id device_ids[],
 244                                        int num_devices)
 245 {
 246     cl_int err;
 247     cl_device_id executor_device_ids[MAX_DEVICES];
 248
 249     int i = 0;
 250     for (auto id : device_ids_m)
 251         executor_device_ids[i++] = device_ids[static_cast<int>(id)];
 252
 253     program_m = clCreateProgramWithBuiltInKernels(context_m,
 254                                           num_devices,
 255                                           executor_device_ids,  // device_list
 256                                           kernel_names.c_str(),
 257                                           &err);
 258     errorCheck(err, __LINE__);
 259
 260     return true;
 261 }
 262
 263 Kernel::Kernel(Device* device, const std::string& name,
 264                const KernelArgs& args, uint8_t device_index):
 265            name_m(name), device_m(device), device_index_m(device_index)
 266 {
 267     TRACE::print("Creating kernel %s\n", name.c_str());
 268     cl_int err;
 269     kernel_m = clCreateKernel(device_m->program_m, name_m.c_str(), &err);
 270     errorCheck(err, __LINE__);
 271
 272     for (int i=0; i < tidl::internal::NUM_CONTEXTS; i++)
 273         event_m[i] = nullptr;
 274
 275     int arg_index = 0;
 276     for (const auto& arg : args)
 277     {
 278         if (!arg.isLocal())
 279         {
 280             if (arg.kind() == DeviceArgInfo::Kind::BUFFER)
 281             {
 282                 cl_mem buffer = device_m->CreateBuffer(arg);
 283
 284                 clSetKernelArg(kernel_m, arg_index, sizeof(cl_mem), &buffer);
 285                 TRACE::print("  Arg[%d]: %p\n", arg_index, buffer);
 286
 287                 if (buffer)
 288                     buffers_m.push_back(buffer);
 289             }
 290             else if (arg.kind() == DeviceArgInfo::Kind::SCALAR)
 291             {
 292                 clSetKernelArg(kernel_m, arg_index, arg.size(), arg.ptr());
 293                 TRACE::print("  Arg[%d]: %p\n", arg_index, arg.ptr());
 294             }
 295             else
 296             {
 297                 assert ("DeviceArgInfo kind not supported");
 298             }
 299         }
 300         else
 301         {
 302             clSetKernelArg(kernel_m, arg_index, arg.size(), NULL);
 303             TRACE::print("  Arg[%d]: local, %d\n", arg_index, arg.size());
 304         }
 305         arg_index++;
 306
 307     }
 308 }
 309
 310 bool Kernel::UpdateScalarArg(uint32_t index, size_t size, const void *value)
 311 {
 312     cl_int ret = clSetKernelArg(kernel_m, index, size, value);
 313     return ret == CL_SUCCESS;
 314 }
 315
 316 Kernel& Kernel::RunAsync(uint32_t context_idx)
 317 {
 318     // Execute kernel
 319     TRACE::print("\tKernel: device %d executing %s, context %d\n",
 320                  device_index_m, name_m.c_str(), context_idx);
 321     cl_int ret = clEnqueueTask(device_m->queue_m[device_index_m],
 322                                kernel_m, 0, 0, &event_m[context_idx]);
 323     errorCheck(ret, __LINE__);
 324
 325     return *this;
 326 }
 327
 328 bool Kernel::Wait(uint32_t context_idx)
 329 {
 330     // Wait called without a corresponding RunAsync
 331     if (event_m[context_idx] == nullptr)
 332         return false;
 333
 334     TRACE::print("\tKernel: waiting context %d...\n", context_idx);
 335     cl_int ret = clWaitForEvents(1, &event_m[context_idx]);
 336     errorCheck(ret, __LINE__);
 337
 338     ret = clReleaseEvent(event_m[context_idx]);
 339     errorCheck(ret, __LINE__);
 340     event_m[context_idx] = nullptr;
 341
 342     TRACE::print("\tKernel: finished execution\n");
 343
 344     return true;
 345 }
 346
 347 extern void CallbackWrapper(void *user_data) __attribute__((weak));
 348
 349 static
 350 void EventCallback(cl_event event, cl_int exec_status, void *user_data)
 351 {
 352     if (exec_status != CL_SUCCESS || user_data == nullptr)  return;
 353     if (CallbackWrapper)  CallbackWrapper(user_data);
 354 }
 355
 356 bool Kernel::AddCallback(void *user_data, uint32_t context_idx)
 357 {
 358     if (event_m[context_idx] == nullptr)
 359         return false;
 360
 361     return clSetEventCallback(event_m[context_idx], CL_COMPLETE, EventCallback,
 362                               user_data) == CL_SUCCESS;
 363 }
 364
 365 Kernel::~Kernel()
 366 {
 367     for (auto b : buffers_m)
 368         device_m->ReleaseBuffer(b);
 369
 370     clReleaseKernel(kernel_m);
 371 }
 372
 373 cl_mem Device::CreateBuffer(const DeviceArgInfo &Arg)
 374 {
 375     size_t  size     = Arg.size();
 376     void   *host_ptr = Arg.ptr();
 377
 378     if (host_ptr == nullptr)
 379     {
 380         TRACE::print("\tOCL Create B:%p\n", nullptr);
 381         return nullptr;
 382     }
 383
 384     bool hostPtrInCMEM = __is_in_malloced_region(host_ptr);
 385
 386     // Conservative till we have sufficient information.
 387     cl_mem_flags flag = CL_MEM_READ_WRITE;
 388
 389     if (hostPtrInCMEM) flag |= (cl_mem_flags)CL_MEM_USE_HOST_PTR;
 390     else               flag |= (cl_mem_flags)CL_MEM_COPY_HOST_PTR;
 391
 392     cl_int       errcode;
 393     cl_mem buffer = clCreateBuffer(context_m,
 394                                    flag,
 395                                    size,
 396                                    host_ptr,
 397                                    &errcode);
 398     errorCheck(errcode, __LINE__);
 399
 400     TRACE::print("\tOCL Create B:%p\n", buffer);
 401
 402     return buffer;
 403 }
 404
 405 void Device::ReleaseBuffer(cl_mem M)
 406 {
 407     TRACE::print("\tOCL Release B:%p\n", M);
 408     clReleaseMemObject(M);
 409 }
 410
 411 /// Release resources associated with an OpenCL device
 412 Device::~Device()
 413 {
 414     TRACE::print("\tOCL Device: deleted\n");
 415     for (unsigned int i = 0; i < device_ids_m.size(); i++)
 416     {
 417         clFinish(queue_m[i]);
 418         clReleaseCommandQueue (queue_m[i]);
 419     }
 420
 421     clReleaseProgram      (program_m);
 422     clReleaseContext      (context_m);
 423 }
 424
 425 void errorCheck(cl_int ret, int line)
 426 {
 427     if (ret != CL_SUCCESS)
 428     {
 429         std::cerr << "ERROR: [ Line: " << line << "] " << error2string(ret) << std::endl;
 430         exit(ret);
 431     }
 432 }
 433
 434 /// Convert OpenCL error codes to a string
 435 const char* error2string(cl_int err)
 436 {
 437     switch(err)
 438     {
 439          case   0: return "CL_SUCCESS";
 440          case  -1: return "CL_DEVICE_NOT_FOUND";
 441          case  -2: return "CL_DEVICE_NOT_AVAILABLE";
 442          case  -3: return "CL_COMPILER_NOT_AVAILABLE";
 443          case  -4: return "CL_MEM_OBJECT_ALLOCATION_FAILURE";
 444          case  -5: return "CL_OUT_OF_RESOURCES";
 445          case  -6: return "CL_OUT_OF_HOST_MEMORY";
 446          case  -7: return "CL_PROFILING_INFO_NOT_AVAILABLE";
 447          case  -8: return "CL_MEM_COPY_OVERLAP";
 448          case  -9: return "CL_IMAGE_FORMAT_MISMATCH";
 449          case -10: return "CL_IMAGE_FORMAT_NOT_SUPPORTED";
 450          case -11: return "CL_BUILD_PROGRAM_FAILURE";
 451          case -12: return "CL_MAP_FAILURE";
 452
 453          case -30: return "CL_INVALID_VALUE";
 454          case -31: return "CL_INVALID_DEVICE_TYPE";
 455          case -32: return "CL_INVALID_PLATFORM";
 456          case -33: return "CL_INVALID_DEVICE";
 457          case -34: return "CL_INVALID_CONTEXT";
 458          case -35: return "CL_INVALID_QUEUE_PROPERTIES";
 459          case -36: return "CL_INVALID_COMMAND_QUEUE";
 460          case -37: return "CL_INVALID_HOST_PTR";
 461          case -38: return "CL_INVALID_MEM_OBJECT";
 462          case -39: return "CL_INVALID_IMAGE_FORMAT_DESCRIPTOR";
 463          case -40: return "CL_INVALID_IMAGE_SIZE";
 464          case -41: return "CL_INVALID_SAMPLER";
 465          case -42: return "CL_INVALID_BINARY";
 466          case -43: return "CL_INVALID_BUILD_OPTIONS";
 467          case -44: return "CL_INVALID_PROGRAM";
 468          case -45: return "CL_INVALID_PROGRAM_EXECUTABLE";
 469          case -46: return "CL_INVALID_KERNEL_NAME";
 470          case -47: return "CL_INVALID_KERNEL_DEFINITION";
 471          case -48: return "CL_INVALID_KERNEL";
 472          case -49: return "CL_INVALID_ARG_INDEX";
 473          case -50: return "CL_INVALID_ARG_VALUE";
 474          case -51: return "CL_INVALID_ARG_SIZE";
 475          case -52: return "CL_INVALID_KERNEL_ARGS";
 476          case -53: return "CL_INVALID_WORK_DIMENSION";
 477          case -54: return "CL_INVALID_WORK_GROUP_SIZE";
 478          case -55: return "CL_INVALID_WORK_ITEM_SIZE";
 479          case -56: return "CL_INVALID_GLOBAL_OFFSET";
 480          case -57: return "CL_INVALID_EVENT_WAIT_LIST";
 481          case -58: return "CL_INVALID_EVENT";
 482          case -59: return "CL_INVALID_OPERATION";
 483          case -60: return "CL_INVALID_GL_OBJECT";
 484          case -61: return "CL_INVALID_BUFFER_SIZE";
 485          case -62: return "CL_INVALID_MIP_LEVEL";
 486          case -63: return "CL_INVALID_GLOBAL_WORK_SIZE";
 487          default: return "Unknown OpenCL error";
 488     }
 489 }
 490
 491 Device::Ptr Device::Create(DeviceType core_type, const DeviceIds& ids,
 492                            const std::string& name)
 493 {
 494     Device::Ptr p(nullptr);
 495     if (core_type == DeviceType::DSP)
 496         p.reset(new DspDevice(ids, name));
 497     else if (core_type == DeviceType::EVE)
 498         p.reset(new EveDevice(ids, name));
 499
 500     return p;
 501 }
 502
 503 // Minimum version of OpenCL required for this version of TIDL API
 504 #define MIN_OCL_VERSION "01.01.17.00"
 505 static bool CheckOpenCLVersion(cl_platform_id id)
 506 {
 507     cl_int err;
 508     size_t length;
 509     err = clGetPlatformInfo(id, CL_PLATFORM_VERSION, 0, nullptr, &length);
 510     if (err != CL_SUCCESS) return false;
 511
 512     std::unique_ptr<char> version(new char[length]);
 513     err = clGetPlatformInfo(id, CL_PLATFORM_VERSION, length, version.get(),
 514                             nullptr);
 515     if (err != CL_SUCCESS) return false;
 516
 517     std::string v(version.get());
 518
 519     if (v.substr(v.find("01."), sizeof(MIN_OCL_VERSION)) >= MIN_OCL_VERSION)
 520         return true;
 521
 522     std::cerr << "TIDL API Error: OpenCL " << MIN_OCL_VERSION
 523               << " or higher required." << std::endl;
 524
 525     return false;
 526 }
 527
 528 static bool PlatformIsAM57()
 529 {
 530     cl_platform_id id;
 531     cl_int err;
 532
 533     err = clGetPlatformIDs(1, &id, nullptr);
 534     if (err != CL_SUCCESS) return false;
 535
 536     if (!CheckOpenCLVersion(id))
 537        return false;
 538
 539     // Check if the device name is AM57
 540     size_t length;
 541     err = clGetPlatformInfo(id, CL_PLATFORM_NAME, 0, nullptr, &length);
 542     if (err != CL_SUCCESS) return false;
 543
 544     std::unique_ptr<char> name(new char[length]);
 545
 546     err = clGetPlatformInfo(id, CL_PLATFORM_NAME, length, name.get(), nullptr);
 547     if (err != CL_SUCCESS) return false;
 548
 549     std::string platform_name(name.get());
 550
 551     if (platform_name.find("AM57") == std::string::npos)
 552         return false;
 553
 554     return true;
 555 }
 556
 557 // TI DL is supported on AM57x - EVE or C66x devices
 558 uint32_t Device::GetNumDevices(DeviceType device_type)
 559 {
 560     if (!PlatformIsAM57()) return 0;
 561
 562     // Convert DeviceType to OpenCL device type
 563     cl_device_type t = (device_type == DeviceType::EVE) ?
 564                                     CL_DEVICE_TYPE_CUSTOM :
 565                                     CL_DEVICE_TYPE_ACCELERATOR;
 566
 567     // Find all the OpenCL devices available
 568     cl_uint num_devices_found;
 569     cl_device_id all_device_ids[MAX_DEVICES];
 570
 571     cl_int errcode = clGetDeviceIDs(0,                   // platform
 572                                     t,                   // device_type
 573                                     MAX_DEVICES,         // num_entries
 574                                     all_device_ids,      // devices
 575                                     &num_devices_found); // num_devices
 576
 577
 578     if (errcode != CL_SUCCESS)            return 0;
 579     if (num_devices_found == 0)           return 0;
 580
 581     // DSP, return the number of compute units since we maintain a
 582     // queue to each compute unit (i.e. C66x DSP)
 583     if (t == CL_DEVICE_TYPE_ACCELERATOR)
 584     {
 585         cl_int num_compute_units;
 586         errcode = clGetDeviceInfo(all_device_ids[0],
 587                                 CL_DEVICE_MAX_COMPUTE_UNITS,
 588                                 sizeof(num_compute_units),
 589                                 &num_compute_units,
 590                                 nullptr);
 591         if (errcode != CL_SUCCESS)
 592             return 0;
 593
 594         return num_compute_units;
 595     }
 596
 597     // EVE, return the number of devices since each EVE is a device
 598     return num_devices_found;
 599 }