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#include <stdio.h>
#include <stdlib.h>
#include <CL/cl.h>
const char * program_src =
"#define __global __attribute__((address_space(1)))\n"
"__kernel\n"
"void pi(__global float * out) \n"
"{\n"
" out[0] = 3.14159f;\n"
"}\n";
int main(int argc, char ** argv)
{
cl_int error;
cl_uint total_platforms;
cl_platform_id platform_id;
cl_uint total_gpu_devices;
cl_device_id device_id;
cl_context context;
cl_command_queue command_queue;
cl_program program;
cl_kernel kernel;
cl_mem out_buffer;
float out_value = 0.0;
size_t global_work_size = 1;
error = clGetPlatformIDs(
1, /* Max number of platform IDs to return */
&platform_id, /* Pointer to platform_id */
&total_platforms); /* Total number of platforms
* found on the system */
if (error != CL_SUCCESS) {
fprintf(stderr, "clGetPlatformIDs() failed: %s\n", clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "There are %u platforms.\n", total_platforms);
error = clGetDeviceIDs(platform_id,
CL_DEVICE_TYPE_GPU,
1,
&device_id,
&total_gpu_devices);
if (error != CL_SUCCESS) {
fprintf(stderr, "clGetDeviceIDs() failed: %s\n", clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "There are %u GPU devices.\n", total_gpu_devices);
context = clCreateContext(NULL, /* Properties */
1, /* Number of devices */
&device_id, /* Device pointer */
NULL, /* Callback for reporting errors */
NULL, /* User data to pass to error callback */
&error); /* Error code */
if (error != CL_SUCCESS) {
fprintf(stderr, "clCreateContext() failed: %s\n", clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clCreateContext() succeeded.\n");
command_queue = clCreateCommandQueue(context,
device_id,
0, /* Command queue properties */
&error); /* Error code */
if (error != CL_SUCCESS) {
fprintf(stderr, "clCreateCommandQueue() failed: %s\n",
clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clCreateCommandQueue() succeeded.\n");
program = clCreateProgramWithSource(context,
1, /* Number of strings */
&program_src,
NULL, /* String lengths, 0 means all the
* strings are NULL terminated. */
&error);
if (error != CL_SUCCESS) {
fprintf(stderr, "clCreateProgramWithSource() failed: %s\n",
clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clCreateProgramWithSource() suceeded.\n");
error = clBuildProgram(program,
1, /* Number of devices */
&device_id,
NULL, /* options */
NULL, /* callback function when compile is complete */
NULL); /* user data for callback */
if (error != CL_SUCCESS) {
char build_str[10000];
error = clGetProgramBuildInfo(program,
device_id,
CL_PROGRAM_BUILD_LOG,
10000, /* Size of output string */
build_str, /* pointer to write the log to */
NULL); /* Number of bytes written to the log */
if (error != CL_SUCCESS) {
fprintf(stderr, "clGetProgramBuildInfo() failed: %s\n",
clUtilErrorString(error));
} else {
fprintf(stderr, "Build Log: \n%s\n\n", build_str);
}
return EXIT_FAILURE;
}
fprintf(stderr, "clBuildProgram() suceeded.\n");
kernel = clCreateKernel(program, "pi", &error);
if (error != CL_SUCCESS) {
fprintf(stderr, "clCreateKernel() failed: %s\n", clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clCreateKernel() suceeded.\n");
out_buffer = clCreateBuffer(context,
CL_MEM_WRITE_ONLY, /* Flags */
sizeof(float), /* Size of buffer */
NULL, /* Pointer to the data */
&error); /* error code */
if (error != CL_SUCCESS) {
fprintf(stderr, "clCreateBuffer() failed: %s\n", clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clCreateBuffer() succeeded.\n");
error = clSetKernelArg(kernel,
0, /* Arg index */
sizeof(cl_mem),
&out_buffer);
if (error != CL_SUCCESS) {
fprintf(stderr, "clSetKernelArg failed: %s\n", clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clSetKernelArg() succeeded.\n");
error = clEnqueueNDRangeKernel(command_queue,
kernel,
1, /* Number of dimensions */
NULL, /* Global work offset */
&global_work_size,
&global_work_size, /* local work size */
0, /* Events in wait list */
NULL, /* Wait list */
NULL); /* Event object for this event */
if (error != CL_SUCCESS) {
fprintf(stderr, "clEnqueueNDRangeKernel() failed: %s\n",
clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clEnqueueNDRangeKernel() suceeded.\n");
error = clEnqueueReadBuffer(command_queue,
out_buffer,
CL_TRUE, /* TRUE means it is a blocking read. */
0, /* Buffer offset to read from. */
sizeof(float), /* Bytes to read */
&out_value, /* Pointer to store the data */
0, /* Events in wait list */
NULL, /* Wait list */
NULL); /* Event object */
if (error != CL_SUCCESS) {
fprintf(stderr, "clEnqueueReadBuffer() failed: %s\n",
clUtilErrorString(error));
return EXIT_FAILURE;
}
fprintf(stderr, "clEnqueueReadBuffer() suceeded.\n");
fprintf(stderr, "pi = %f\n", out_value);
return EXIT_SUCCESS;
}
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