CLBlast/samples/dtrsm.cpp

121 lines
4.9 KiB
C++

// =================================================================================================
// 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 DTRSM routine. It is a stand-alone example, but it does
// require the Khronos C++ OpenCL API header file (downloaded by CMake). The example uses C++
// features, but CLBlast can also be used using the regular C-style OpenCL API.
//
// 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 <vector>
#define CL_USE_DEPRECATED_OPENCL_1_1_APIS // to disable deprecation warnings
#define CL_USE_DEPRECATED_OPENCL_1_2_APIS // to disable deprecation warnings
// Includes the C++ OpenCL API. If not yet available, it can be found here:
// https://raw.githubusercontent.com/KhronosGroup/OpenCL-CLHPP/main/include/CL/opencl.hpp
#define CL_HPP_TARGET_OPENCL_VERSION 120
#define CL_HPP_MINIMUM_OPENCL_VERSION 120
#define CL_TARGET_OPENCL_VERSION 120
#include "opencl.hpp"
// Includes the CLBlast library
#include <clblast.h>
// =================================================================================================
// Example use of the double-precision Xtrsm routine DTRSM, solving A*X = alpha*B, storing the
// result in the memory of matrix B. Uses row-major storage (C-style).
int main() {
// OpenCL platform/device settings
const auto platform_id = 0;
const auto device_id = 0;
// Example TRSM arguments
const size_t m = 4;
const size_t n = 3;
const double alpha = 1.0;
const auto a_ld = m;
const auto b_ld = n;
// Initializes the OpenCL platform
auto platforms = std::vector<cl::Platform>();
cl::Platform::get(&platforms);
if (platforms.size() == 0 || platform_id >= platforms.size()) { return 1; }
auto platform = platforms[platform_id];
// Initializes the OpenCL device
auto devices = std::vector<cl::Device>();
platform.getDevices(CL_DEVICE_TYPE_ALL, &devices);
if (devices.size() == 0 || device_id >= devices.size()) { return 1; }
auto device = devices[device_id];
// Creates the OpenCL context, queue, and an event
auto device_as_vector = std::vector<cl::Device>{device};
auto context = cl::Context(device_as_vector);
auto queue = cl::CommandQueue(context, device);
auto event = cl_event{nullptr};
// Populate host matrices with some example data
auto host_a = std::vector<double>({1.0, 2.0, 1.0, -2.0,
0.0, -1.0, -2.0, 0.0,
0.0, 0.0, 1.0, 1.0,
0.0, 0.0, 0.0, -1.0});
auto host_b = std::vector<double>({-1.0, -1.0, 3.0,
1.0, -3.0, 2.0,
1.0, 1.0, -1.0,
4.0, -1.0, -2.0});
// Expected result:
// 8 -5 2
// -11 3 4
// 5 0 -3
// -4 1 2
// Copy the matrices to the device
auto device_a = cl::Buffer(context, CL_MEM_READ_WRITE, host_a.size()*sizeof(double));
auto device_b = cl::Buffer(context, CL_MEM_READ_WRITE, host_b.size()*sizeof(double));
queue.enqueueWriteBuffer(device_a, CL_TRUE, 0, host_a.size()*sizeof(double), host_a.data());
queue.enqueueWriteBuffer(device_b, CL_TRUE, 0, host_b.size()*sizeof(double), host_b.data());
// Call the DTRSM routine. Note that the type of alpha and beta (double) determine the precision.
auto queue_plain = queue();
auto status = clblast::Trsm(clblast::Layout::kRowMajor, clblast::Side::kLeft,
clblast::Triangle::kUpper, clblast::Transpose::kNo,
clblast::Diagonal::kNonUnit,
m, n,
alpha,
device_a(), 0, a_ld,
device_b(), 0, b_ld,
&queue_plain, &event);
// Retrieves the results
if (status == clblast::StatusCode::kSuccess) {
clWaitForEvents(1, &event);
clReleaseEvent(event);
}
queue.enqueueReadBuffer(device_b, CL_TRUE, 0, host_b.size()*sizeof(double), host_b.data());
// Example completed. See "clblast.h" for status codes (0 -> success).
printf("Completed TRSM with status %d and results:\n", static_cast<int>(status));
for (auto i = size_t{0}; i < m; ++i) {
for (auto j = size_t{0}; j < n; ++j) {
printf("%3.0f ", host_b[i * b_ld + j]);
}
printf("\n");
}
return 0;
}
// =================================================================================================