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Diffstat (limited to 'samples/sasum.c')
-rw-r--r-- | samples/sasum.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/samples/sasum.c b/samples/sasum.c new file mode 100644 index 00000000..3b20d301 --- /dev/null +++ b/samples/sasum.c @@ -0,0 +1,96 @@ + +// ================================================================================================= +// This file is part of the CLBlast project. The project is licensed under Apache Version 2.0. This +// project loosely follows the Google C++ styleguide and uses a tab-size of two spaces and a max- +// width of 100 characters per line. +// +// Author(s): +// Cedric Nugteren <www.cedricnugteren.nl> +// +// This file demonstrates the use of the SASUM routine. It is pure C99 and demonstrates the use of +// the C API to the CLBlast library. +// +// Note that this example is meant for illustration purposes only. CLBlast provides other programs +// for performance benchmarking ('client_xxxxx') and for correctness testing ('test_xxxxx'). +// +// ================================================================================================= + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +// Includes the CLBlast library (C interface) +#include <clblast_c.h> + +// ================================================================================================= + +// Example use of the single-precision routine SASUM +int main(void) { + + // OpenCL platform/device settings + const size_t platform_id = 0; + const size_t device_id = 0; + + // Example SASUM arguments + const size_t n = 1000; + const float input_value = -1.5f; + + // Initializes the OpenCL platform + cl_uint num_platforms; + clGetPlatformIDs(0, NULL, &num_platforms); + cl_platform_id* platforms = (cl_platform_id*)malloc(num_platforms*sizeof(cl_platform_id)); + clGetPlatformIDs(num_platforms, platforms, NULL); + cl_platform_id platform = platforms[platform_id]; + + // Initializes the OpenCL device + cl_uint num_devices; + clGetDeviceIDs(platform, CL_DEVICE_TYPE_ALL, 0, NULL, &num_devices); + cl_device_id* devices = (cl_device_id*)malloc(num_devices*sizeof(cl_device_id)); + clGetDeviceIDs(platform, CL_DEVICE_TYPE_ALL, num_devices, devices, NULL); + cl_device_id device = devices[device_id]; + + // Creates the OpenCL context, queue, and an event + cl_context context = clCreateContext(NULL, 1, &device, NULL, NULL, NULL); + cl_command_queue queue = clCreateCommandQueue(context, device, 0, NULL); + cl_event event = NULL; + + // Populate host data structures with some example data + float* host_input = (float*)malloc(sizeof(float)*n); + float* host_output = (float*)malloc(sizeof(float)*1); + for (size_t i=0; i<n; ++i) { host_input[i] = input_value; } + for (size_t i=0; i<1; ++i) { host_output[i] = 0.0f; } + + // Copy the data-structures to the device + cl_mem device_input = clCreateBuffer(context, CL_MEM_READ_WRITE, n*sizeof(float), NULL, NULL); + cl_mem device_output = clCreateBuffer(context, CL_MEM_READ_WRITE, 1*sizeof(float), NULL, NULL); + clEnqueueWriteBuffer(queue, device_input, CL_TRUE, 0, n*sizeof(float), host_input, 0, NULL, NULL); + clEnqueueWriteBuffer(queue, device_output, CL_TRUE, 0, 1*sizeof(float), host_output, 0, NULL, NULL); + + // Call the SASUM routine. + StatusCode status = CLBlastSasum(n, + device_output, 0, + device_input, 0, 1, + &queue, &event); + + // Wait for completion + clWaitForEvents(1, &event); + + // Copies the result back to the host + clEnqueueReadBuffer(queue, device_output, CL_TRUE, 0, 1*sizeof(float), host_output, 0, NULL, NULL); + + // Example completed. See "clblast_c.h" for status codes (0 -> success). + printf("Completed SASUM with status %d: %d * |%.1lf| = %.1lf\n", status, n, input_value, host_output[0]); + + // Clean-up + free(platforms); + free(devices); + free(host_input); + free(host_output); + clReleaseMemObject(device_input); + clReleaseMemObject(device_output); + clReleaseCommandQueue(queue); + clReleaseContext(context); + return 0; +} + +// ================================================================================================= |