我正在尝试使用以前工作过的 NVIDIA 卡在 Ubuntu 上编译一个 openCL 程序,
#include <CL/cl.h>
#include <iostream>
#include <vector>
using namespace std;
int main() {
cl_platform_id platform;
cl_device_id device;
cl_context context;
cl_command_queue command_queue;
cl_int error;
if(clGetPlatformIDs(1, &platform, NULL) != CL_SUCCESS) {
cout << "platform error" << endl;
}
if(clGetDeviceIDs(platform, CL_DEVICE_TYPE_GPU, 1, &device, NULL) != CL_SUCCESS) {
cout << "device error" << endl;
}
context = clCreateContext(NULL, 1, &device, NULL, NULL, &error);
if(error != CL_SUCCESS) {
cout << "context error" << endl;
}
command_queue = clCreateCommandQueue(context, device, 0, &error);
if(error != CL_SUCCESS) {
cout << "command queue error" << endl;
}
return 0;
}
我是这样编译的,
g++ -I/usr/local/cuda/include -L/usr/lib/nvidia-current -lOpenCL opencl.cpp
我得到了这个结果
/tmp/ccAdS9ig.o: In function `main':
opencl.cpp:(.text+0x1a): undefined reference to `clGetPlatformIDs'
opencl.cpp:(.text+0x3d): undefined reference to `clGetDeviceIDs'
opencl.cpp:(.text+0x65): undefined reference to `clCreateContext'
opencl.cpp:(.text+0x85): undefined reference to `clCreateCommandQueue'
collect2: ld returned 1 exit status
但是 nm -D/usr/lib/nvidia-current/libOpenCL.so
告诉我 libOpenCL.so 至少包含 clGetPlatformIDs
0000000000002400 T clGetKernelWorkGroupInfo
0000000000002140 T clGetMemObjectInfo
0000000000002e80 T clGetPlatformIDs
0000000000002de0 T clGetPlatformInfo
0000000000002310 T clGetProgramBuildInfo
00000000000022f0 T clGetProgramInfo
00000000000021f0 T clGetSamplerInfo
我是不是错过了什么。
最佳答案
链接时,库和源文件的顺序会有所不同。例如对于您的情况,
g++ -I/usr/local/cuda/include -L/usr/lib/nvidia-current -lOpenCL opencl.cpp
OpenCL 库中定义的函数可能不会被加载,因为在它们之前没有任何东西要求查找。但是,如果您使用,
g++ opencl.cpp -I/usr/local/cuda/include -L/usr/lib/nvidia-current -lOpenCL
那么任何对函数的请求都会在 OpenCL 库中找到并被加载。
https://stackoverflow.com/questions/7783345/