我刚刚开始尝试使用OpenCL。我试图制作一个可以增加两个2-d数组的内核。我已经用向量完成了这个,但是在二维中我只得到第一行的结果。我尝试过实现我发现的一些解决方案,但是每一个解决方案都只是第一行。 执行中的图像: http://i.imgur.com/lJqSURV.png
这是我的主机文件:
#include "stdafx.h"
#include <CL/cl.hpp>
#include <vector>
#include <iostream>
#include "util.hpp" // utility library
#define __CL_ENABLE_EXCEPTIONS
#define ROWS (5)
#define COLUMNS (5)
#include "metrics.h"
/*Start main()*/
int main(void)
{
int A = 4;
/*Define the vectors for operands and result*/
float** h_x = new float*[ROWS];
float** h_y = new float*[ROWS];
float** h_s = new float*[ROWS];
for (int i = 0; i < ROWS; ++i){
h_x[i] = new float[COLUMNS];
}
for (int i = 0; i < ROWS; ++i){
h_y[i] = new float[COLUMNS];
}
for (int i = 0; i < ROWS; ++i){
h_s[i] = new float[COLUMNS];
}
// Fill vectors a and b with random float values
for (int i = 0; i < ROWS; i++)
{
for (int j = 0; j < COLUMNS; j++){
h_x[i][j] = rand() / (float)RAND_MAX;
h_y[i][j] = rand() / (float)RAND_MAX;
h_s[i][j] = 0.0;
}
}
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
// Get all platforms (drivers)
std::vector<cl::Platform> all_platforms;
cl::Platform::get(&all_platforms);
if (all_platforms.size() == 0){ // Check for issues
std::cout << " No platforms found. Check OpenCL installation!\n";
exit(1);
}
cl::Platform default_platform = all_platforms[0];
std::cout << "Using platform: " << default_platform.getInfo<CL_PLATFORM_NAME>() << "\n";
// Get default device of the default platform
std::vector<cl::Device> all_devices;
default_platform.getDevices(CL_DEVICE_TYPE_ALL, &all_devices);
if (all_devices.size() == 0){ // Check for issues
std::cout << " No devices found. Check OpenCL installation!\n";
exit(1);
}
cl::Device default_device = all_devices[0];
std::cout << "Using device: " << default_device.getInfo<CL_DEVICE_NAME>() << "\n";
// Create an OpenCL context
cl::Context context({ default_device });
cl::Program program(context, util::loadProgram("saxy_kernel.cl"), true);
if (program.build({ default_device }) != CL_SUCCESS){
std::cout << " Error building: " << program.getBuildInfo<CL_PROGRAM_BUILD_LOG>(default_device) << "\n";
getchar();
exit(1);
}
// create buffers on the device
cl::Buffer buffer_X(context, CL_MEM_READ_WRITE, sizeof(float)* ROWS*COLUMNS);
cl::Buffer buffer_Y(context, CL_MEM_READ_WRITE, sizeof(float)* ROWS*COLUMNS);
cl::Buffer buffer_S(context, CL_MEM_READ_WRITE, sizeof(float)* ROWS*COLUMNS);
cl::Buffer buffer_A(context, CL_MEM_READ_WRITE, sizeof(int));
//create queue to which we will push commands for the device.
cl::CommandQueue queue(context, default_device);
StartCounter();
//write arrays A and B to the device
queue.enqueueWriteBuffer(buffer_X, CL_TRUE, 0, sizeof(float)* ROWS*COLUMNS, &h_x[0][0]);
queue.enqueueWriteBuffer(buffer_Y, CL_TRUE, 0, sizeof(float)* ROWS*COLUMNS, &h_y[0][0]);
queue.enqueueWriteBuffer(buffer_A, CL_TRUE, 0, sizeof(int), &A);
//run the kernel
cl::Kernel kernel_add = cl::Kernel(program, "simple_add");
kernel_add.setArg(0, buffer_X);
kernel_add.setArg(1, buffer_Y);
kernel_add.setArg(2, buffer_S);
kernel_add.setArg(3, buffer_A);
queue.enqueueNDRangeKernel(kernel_add, cl::NullRange, cl::NDRange(5,5), cl::NullRange);
queue.finish();
//read result C from the device to array C
queue.enqueueReadBuffer(buffer_S, CL_TRUE, 0, sizeof(float)* ROWS * COLUMNS, &h_s[0][0]);
std::cout << "Kernel execution time: " << GetCounter() << "ms \n";
/*Print vectors*/
std::cout << "\nMatrix #1: \n";
for (int i = 0; i<ROWS; i++){
std::cout << "\n";
for (int j = 0; j<COLUMNS; j++){
std::cout << "" << h_x[i][j] << "\t ";
}
}
std::cout << "\n\nMatrix #2: \n";
for (int i = 0; i<ROWS; i++){
std::cout << "\n";
for (int j = 0; j<COLUMNS; j++){
std::cout << "" << h_y[i][j] << "\t ";
}
}
std::cout << "\n\nResult: \n";
for (int i = 0; i<ROWS; i++){
std::cout << "\n";
for (int j = 0; j<COLUMNS; j++){
std::cout << "" << h_s[i][j] << "\t ";
}
}
getchar();
return 0;
}
这里是内核:
__kernel void kernel simple_add(
__global float* X,
__global float* Y,
__global float* S,
__global int *A){
S[get_global_id(0)] = X[get_global_id(0)] * Y[get_global_id(0)];
/* Var defs
int k;
int i = get_global_id(0);
int j = get_global_id(1);
float tmp;
if ( (i < 5) && (j < 5))
{
tmp = 0.0;
for(k=0;k<5;k++)
tmp += X[i*5+k] * Y[k*5+j];
S[i*5+j] = tmp;
}*/
}
我确定我做的事情真的错误,但我无法找出它是什么。任何帮助将不胜感激。
答案 0 :(得分:1)
您的内核代码很好,就像您创建OpenCL缓冲区和启动内核一样。问题在于您的数据在主机上的表示方式,以及您如何将其复制到设备上。
您的OpenCL缓冲区是一维数组,这是必要的。然而,您的主机阵列是2D,这意味着相邻的行不是连续的(2D数组是一个指针数组)。
(最简单)修复方法是将主机上的存储线性化,以匹配设备的数据布局:
float* h_x = new float[ROWS*COLUMNS];
for (int i = 0; i < ROWS; ++i){
for (int j = 0; j < COLUMNS; ++j){
h_x[j + i*COLUMNS] = rand() / (float)RAND_MAX;;
}
}