opencl.c

#pragma OPENCL EXTENSION cl_khr_icd : enable

#include <CL/cl.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define NUM_DATA 100

#define CL_CHECK(_expr)                                                         \
   do {                                                                         \
     cl_int _err = _expr;                                                       \
     if (_err == CL_SUCCESS)                                                    \
       break;                                                                   \
     fprintf(stderr, "OpenCL Error: '%s' returned %d!\n", #_expr, (int)_err);   \
     abort();                                                                   \
   } while (0)

#define CL_CHECK_ERR(_expr)                                                     \
   ({                                                                           \
     cl_int _err = CL_INVALID_VALUE;                                            \
     typeof(_expr) _ret = _expr;                                                \
     if (_err != CL_SUCCESS) {                                                  \
       fprintf(stderr, "OpenCL Error: '%s' returned %d!\n", #_expr, (int)_err); \
       abort();                                                                 \
     }                                                                          \
     _ret;                                                                      \
   })

void pfn_notify(const char *errinfo, const void *private_info, size_t cb, void *user_data)
{
fprintf(stderr, "OpenCL Error (via pfn_notify): %s\n", errinfo);
}

int main()
{
cl_platform_id platforms[100];
cl_uint platforms_n = 0;
//CL_CHECK(clIcdGetPlatformIDsKHR(100, platforms, &platforms_n));
CL_CHECK(clGetPlatformIDs(100, platforms, &platforms_n));

printf("=== %d OpenCL platform(s) found: ===\n", platforms_n);
for (int i=0; i<platforms_n; i++)
{
char buffer[10240];
printf("  -- %d --\n", i);
CL_CHECK(clGetPlatformInfo(platforms[i], CL_PLATFORM_PROFILE, 10240, buffer, NULL));
printf("  PROFILE = %s\n", buffer);
CL_CHECK(clGetPlatformInfo(platforms[i], CL_PLATFORM_VERSION, 10240, buffer, NULL));
printf("  VERSION = %s\n", buffer);
CL_CHECK(clGetPlatformInfo(platforms[i], CL_PLATFORM_NAME, 10240, buffer, NULL));
printf("  NAME = %s\n", buffer);
CL_CHECK(clGetPlatformInfo(platforms[i], CL_PLATFORM_VENDOR, 10240, buffer, NULL));
printf("  VENDOR = %s\n", buffer);
CL_CHECK(clGetPlatformInfo(platforms[i], CL_PLATFORM_EXTENSIONS, 10240, buffer, NULL));
printf("  EXTENSIONS = %s\n", buffer);
}

if (platforms_n == 0)
return 1;

cl_device_id devices[100];
cl_uint devices_n = 0;
// CL_CHECK(clGetDeviceIDs(NULL, CL_DEVICE_TYPE_ALL, 100, devices, &devices_n));
CL_CHECK(clGetDeviceIDs(platforms[0], CL_DEVICE_TYPE_GPU, 100, devices, &devices_n));


printf("=== %d OpenCL device(s) found on platform:\n", platforms_n);
for (int i=0; i<devices_n; i++)
{
char buffer[10240];
cl_uint buf_uint;
cl_ulong buf_ulong;
printf("  -- %d --\n", i);
CL_CHECK(clGetDeviceInfo(devices[i], CL_DEVICE_NAME, sizeof(buffer), buffer, NULL));
printf("  DEVICE_NAME = %s\n", buffer);
CL_CHECK(clGetDeviceInfo(devices[i], CL_DEVICE_VENDOR, sizeof(buffer), buffer, NULL));
printf("  DEVICE_VENDOR = %s\n", buffer);
CL_CHECK(clGetDeviceInfo(devices[i], CL_DEVICE_VERSION, sizeof(buffer), buffer, NULL));
printf("  DEVICE_VERSION = %s\n", buffer);
CL_CHECK(clGetDeviceInfo(devices[i], CL_DRIVER_VERSION, sizeof(buffer), buffer, NULL));
printf("  DRIVER_VERSION = %s\n", buffer);
CL_CHECK(clGetDeviceInfo(devices[i], CL_DEVICE_MAX_COMPUTE_UNITS, sizeof(buf_uint), &buf_uint, NULL));
printf("  DEVICE_MAX_COMPUTE_UNITS = %u\n", (unsigned int)buf_uint);
CL_CHECK(clGetDeviceInfo(devices[i], CL_DEVICE_MAX_CLOCK_FREQUENCY, sizeof(buf_uint), &buf_uint, NULL));
printf("  DEVICE_MAX_CLOCK_FREQUENCY = %u\n", (unsigned int)buf_uint);
CL_CHECK(clGetDeviceInfo(devices[i], CL_DEVICE_GLOBAL_MEM_SIZE, sizeof(buf_ulong), &buf_ulong, NULL));
printf("  DEVICE_GLOBAL_MEM_SIZE = %llu\n", (unsigned long long)buf_ulong);
}

if (devices_n == 0)
return 1;

cl_context context;
context = CL_CHECK_ERR(clCreateContext(NULL, 1, devices, &pfn_notify, NULL, &_err));

const char *program_source[] = {
"__kernel void simple_demo(__global int *src, __global int *dst, int factor)\n",
"{\n",
"int i = get_global_id(0);\n",
"src[i] = src[i] * factor;\n",
"}\n"
};

cl_program program;
program = CL_CHECK_ERR(clCreateProgramWithSource(context, sizeof(program_source)/sizeof(*program_source), program_source, NULL, &_err));
    if (clBuildProgram(program, 1, devices, "", NULL, NULL) != CL_SUCCESS) {
    char buffer[10240];
    clGetProgramBuildInfo(program, devices[0], CL_PROGRAM_BUILD_LOG, sizeof(buffer), buffer, NULL);
    fprintf(stderr, "CL Compilation failed:\n%s", buffer);
    abort();
    }
    CL_CHECK(clUnloadCompiler());

    int* a = (int *)malloc (sizeof (int)*NUM_DATA);
    int *c = (int*)malloc(sizeof (int)*NUM_DATA);
    int i;
	for (int i = 0; i < NUM_DATA; i++)
	{
    	a[i] = i;
    	c[i] = 0;
    }
    
    cl_mem input_buffer;
    input_buffer = CL_CHECK_ERR(clCreateBuffer(context, CL_MEM_READ_ONLY | CL_MEM_USE_HOST_PTR, sizeof(int)*NUM_DATA, a, &_err));

    cl_mem output_buffer;
    output_buffer = CL_CHECK_ERR(clCreateBuffer(context, CL_MEM_WRITE_ONLY | CL_MEM_USE_HOST_PTR, sizeof(int)*NUM_DATA, c, &_err));

    int factor = 2;

    cl_kernel kernel;
    kernel = CL_CHECK_ERR(clCreateKernel(program, "simple_demo", &_err));
    CL_CHECK(clSetKernelArg(kernel, 0, sizeof(input_buffer), &input_buffer));
    CL_CHECK(clSetKernelArg(kernel, 1, sizeof(output_buffer), &output_buffer));
    CL_CHECK(clSetKernelArg(kernel, 2, sizeof(factor), &factor));

    cl_command_queue queue;
     
    queue = CL_CHECK_ERR(clCreateCommandQueue(context, devices[0], 0, &_err));
    int *input_map = (int *)CL_CHECK_ERR(clEnqueueMapBuffer(queue, input_buffer, CL_TRUE,CL_MAP_READ | CL_MAP_WRITE, 0, sizeof(int)*NUM_DATA, 0, NULL, NULL, &_err));
    
    clEnqueueUnmapMemObject (queue, input_buffer, input_map, 0, NULL, NULL); 
    cl_event kernel_completion;
    size_t global_work_size[1] = { NUM_DATA };
    CL_CHECK(clEnqueueNDRangeKernel(queue, kernel, 1, NULL, global_work_size, NULL, 0, NULL, &kernel_completion));
    CL_CHECK(clWaitForEvents(1, &kernel_completion));
    CL_CHECK(clReleaseEvent(kernel_completion));
    
    input_map = (int *)CL_CHECK_ERR(clEnqueueMapBuffer(queue, input_buffer, CL_TRUE,CL_MAP_READ | CL_MAP_WRITE, 0, sizeof(int)*NUM_DATA, 0, NULL, NULL, &_err));
    clEnqueueUnmapMemObject(queue,input_buffer,input_map,0,NULL,NULL);        
    
    printf("Result:");
    for (int i=0; i<NUM_DATA; i++) {
    int data;
    //CL_CHECK(clEnqueueReadBuffer(queue, input_buffer, CL_TRUE, i*sizeof(int), sizeof(int), &a[i], 0, NULL, NULL));
    printf(" %d", a[i]);
    }
    printf("\n");

    clFinish (queue);
    CL_CHECK(clReleaseMemObject(input_buffer));
    CL_CHECK(clReleaseMemObject(output_buffer));

    CL_CHECK(clReleaseKernel(kernel));
    CL_CHECK(clReleaseProgram(program));
    CL_CHECK(clReleaseContext(context));

    return 0;
}