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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 with the C++ CUDA API of CLBlast.
//
// 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 <cstdio>
#include <chrono>
#include <vector>
// Includes the CUDA driver API
#include <cuda.h>
// Includes the CLBlast library
#include <clblast_cuda.h>
// =================================================================================================
// Example use of the single-precision Xgemm routine SGEMM
int main() {
// CUDA device selection
const auto 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 auto a_ld = k;
const auto b_ld = n;
const auto c_ld = n;
// Initializes the OpenCL device
cuInit(0);
CUdevice device;
cuDeviceGet(&device, device_id);
// Creates the OpenCL context and stream
CUcontext context;
cuCtxCreate(&context, 0, device);
CUstream stream;
cuStreamCreate(&stream, CU_STREAM_NON_BLOCKING);
// Populate host matrices with some example data
auto host_a = std::vector<float>(m*k);
auto host_b = std::vector<float>(n*k);
auto host_c = std::vector<float>(m*n);
for (auto &item: host_a) { item = 12.193f; }
for (auto &item: host_b) { item = -8.199f; }
for (auto &item: host_c) { item = 0.0f; }
// Copy the matrices to the device
CUdeviceptr device_a;
CUdeviceptr device_b;
CUdeviceptr device_c;
cuMemAlloc(&device_a, host_a.size()*sizeof(float));
cuMemAlloc(&device_b, host_b.size()*sizeof(float));
cuMemAlloc(&device_c, host_c.size()*sizeof(float));
cuMemcpyHtoDAsync(device_a, host_a.data(), host_a.size()*sizeof(float), stream);
cuMemcpyHtoDAsync(device_b, host_b.data(), host_b.size()*sizeof(float), stream);
cuMemcpyHtoDAsync(device_c, host_c.data(), host_c.size()*sizeof(float), stream);
// Start the timer
auto start_time = std::chrono::steady_clock::now();
// Call the SGEMM routine. Note that the type of alpha and beta (float) determine the precision.
auto status = clblast::Gemm(clblast::Layout::kRowMajor,
clblast::Transpose::kNo, clblast::Transpose::kNo,
m, n, k,
alpha,
device_a, 0, a_ld,
device_b, 0, b_ld,
beta,
device_c, 0, c_ld,
context, device);
cuStreamSynchronize(stream);
// Record the execution time
auto elapsed_time = std::chrono::steady_clock::now() - start_time;
auto time_ms = std::chrono::duration<double,std::milli>(elapsed_time).count();
// Example completed. See "clblast_cuda.h" for status codes (0 -> success).
printf("Completed SGEMM in %.3lf ms with status %d\n", time_ms, static_cast<int>(status));
// Clean-up
cuMemFree(device_a);
cuMemFree(device_b);
cuMemFree(device_c);
cuStreamDestroy(stream);
return 0;
}
// =================================================================================================
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