Why can't I create a kernel (CL_INVALID_PROGRAM_EXECUTABLE) after successfully compiling an OpenCL program?

Question

In the following program, I compile a kernel for the first device on the first platform:

const char* kernel_source_code = R"(
__kernel void vectorAdd(
    __global float       * __restrict C,
    __global float const * __restrict A,
    __global float const * __restrict B,
    unsigned long length)
{
  int i = get_global_id(0);
  if (i < length)
    C[i] = A[i] + B[i];
}
)";

cl_int status;
cl_platform platform_id;
status = clGetPlatformIDs(1, &platform_id, nullptr);
ensure_success(status);

cl_device device_id;
status = clGetDeviceIDs(platform_id, CL_DEVICE_TYPE_DEFAULT, 1, &device_id, nullptr);
ensure_success(status);

cl_context context_id = clCreateContext(nullptr, 1, &device_id, nullptr, nullptr, &status);
ensure_success(status);

size_t length = strlen(kernel_source_code);
cl_program program_id = clCreateProgramWithSource(context_id, 1, &kernel_source_code, &length, &status);
ensure_success(status);

status = clCompileProgram(
    program_id,
    1, &device_id, // single device
    "", // no special options
    0, nullptr, nullptr, // num headers, header sources, header names
    nullptr, nullptr // no callback
    );
ensure_success(status);

cl_kernel kernel = clCreateKernel(program_id, "vectorAdd", &status);
ensure_success(status);

but - the last API call, the kernel creation, fails with CL_INVALID_PROGRAM_EXECUTABLE, which means "there is no successfully built executable for [the] program".

Why am I getting this failure, if my compilation has succeeded?

einpoklum · Accepted Answer · 2025-06-02 22:14:49Z

0

The OpenCL documentation doesn't clarify this, but - it's not enough that your compiled program has "binaries", you need it to have linked "binaries", i.e. you have to link your program before you can get any kernels. After your clCompileProgram() call, add:

cl_program linked = clLinkProgram(context_id,
  1, &device_id, // devices,
  "", // No link options
  1, &program_id,
  nullptr, nullptr, // no callback
  &status);
ensure_success(status);

Now you can create your kernel (that is, create it using the linked variable, not the program_id.

Alternatively you could use clBuildKernel().

edited Jun 2 at 22:14

answered Jun 2 at 19:10

einpoklum

137k86 gold badges445 silver badges913 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Why can't I create a kernel (CL_INVALID_PROGRAM_EXECUTABLE) after successfully compiling an OpenCL program?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related