Added SGEMM example using the C API

1 files changed, 108 insertions, 0 deletions

diff --git a/samples/sgemm.c b/samples/sgemm.c
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+++ b/samples/sgemm.c
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+
+// =================================================================================================
+// 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 SGEMM 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 <stdio.h>
+#include <string.h>
+
+// Includes the CLBlast library (C interface)
+#include <clblast_c.h>
+
+// =================================================================================================
+
+// Example use of the single-precision routine SGEMM
+int main(void) {
+
+  // OpenCL platform/device settings
+  const size_t platform_id = 0;
+  const size_t device_id = 0;
+
+  // Example SGEMM arguments
+  const size_t m = 128;
+  const size_t n = 64;
+  const size_t k = 512;
+  const float alpha = 0.7f;
+  const float beta = 1.0f;
+  const size_t a_ld = k;
+  const size_t b_ld = n;
+  const size_t c_ld = n;
+
+  // 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 (note: example for GPU devices only)
+  cl_uint num_devices;
+  clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, 0, NULL, &num_devices);
+  cl_device_id* devices = (cl_device_id*)malloc(num_devices*sizeof(cl_device_id));
+  clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, 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 matrices with some example data
+  float* host_a = (float*)malloc(sizeof(float)*m*k);
+  float* host_b = (float*)malloc(sizeof(float)*n*k);
+  float* host_c = (float*)malloc(sizeof(float)*m*n);
+  for (size_t i=0; i<m*k; ++i) { host_a[i] = 12.193f; }
+  for (size_t i=0; i<n*k; ++i) { host_b[i] = -8.199f; }
+  for (size_t i=0; i<m*n; ++i) { host_c[i] = 0.0f; }
+
+  // Copy the matrices to the device
+  cl_mem device_a = clCreateBuffer(context, CL_MEM_READ_WRITE, m*k*sizeof(float), NULL, NULL);
+  cl_mem device_b = clCreateBuffer(context, CL_MEM_READ_WRITE, n*k*sizeof(float), NULL, NULL);
+  cl_mem device_c = clCreateBuffer(context, CL_MEM_READ_WRITE, m*n*sizeof(float), NULL, NULL);
+  clEnqueueWriteBuffer(queue, device_a, CL_TRUE, 0, m*k*sizeof(float), host_a, 0, NULL, NULL);
+  clEnqueueWriteBuffer(queue, device_b, CL_TRUE, 0, n*k*sizeof(float), host_b, 0, NULL, NULL);
+  clEnqueueWriteBuffer(queue, device_c, CL_TRUE, 0, m*n*sizeof(float), host_c, 0, NULL, NULL);
+
+  // Call the SGEMM routine.
+  StatusCode status = CLBlastSgemm(kRowMajor, kNo, kNo,
+                                   m, n, k,
+                                   alpha,
+                                   device_a, 0, a_ld,
+                                   device_b, 0, b_ld,
+                                   beta,
+                                   device_c, 0, c_ld,
+                                   &queue, &event);
+
+  // Wait for completion
+  clWaitForEvents(1, &event);
+
+  // Example completed. See "clblast_c.h" for status codes (0 -> success).
+  printf("Completed with status %d\n", status);
+
+  // Clean-up
+  free(platforms);
+  free(devices);
+  free(host_a);
+  free(host_b);
+  free(host_c);
+  clReleaseMemObject(device_a);
+  clReleaseMemObject(device_b);
+  clReleaseMemObject(device_c);
+  clReleaseCommandQueue(queue);
+  clReleaseContext(context);
+  return 0;
+}
+
+// =================================================================================================