如何分离CUDA code成多个文件 [英] How to separate CUDA code into multiple files

问题描述

我想分开的CUDA程序分为两个独立的.CU文件努力边缘接近用C写一个真正的应用程序++。我有一个简单的小程序是：

I am trying separate a CUDA program into two separate .cu files in effort to edge closer to writing a real app in C++. I have a simple little program that:

分配的主机和设备上的存储器中。结果，
初始化主机阵列一系列数字。
主机阵列复制到设备阵列
发现该阵列中的所有元素的使用设备内核的方
复制装置阵列回主机阵列
打印结果

Allocates a memory on the host and the device.
Initializes the host array to a series of numbers. Copies the host array to a device array Finds the square of all the elements in the array using a device kernel Copies the device array back to the host array Prints the results

如果我把它们都放在一个.CU文件，并运行这个伟大的工程。当我把它分成两个独立的文件我开始得到链接错误。像所有我最近的问题，我知道这是小东西，但它是什么？

This works great if I put it all in one .cu file and run it. When I split it into two separate files I start getting linking errors. Like all my recent questions, I know this is something small, but what is it?

KernelSupport.cu

KernelSupport.cu

#ifndef _KERNEL_SUPPORT_
#define _KERNEL_SUPPORT_

#include <iostream>
#include <MyKernel.cu>

int main( int argc, char** argv) 
{
    int* hostArray;
    int* deviceArray;
    const int arrayLength = 16;
    const unsigned int memSize = sizeof(int) * arrayLength;

    hostArray = (int*)malloc(memSize);
    cudaMalloc((void**) &deviceArray, memSize);

    std::cout << "Before device\n";
    for(int i=0;i<arrayLength;i++)
    {
        hostArray[i] = i+1;
        std::cout << hostArray[i] << "\n";
    }
    std::cout << "\n";

    cudaMemcpy(deviceArray, hostArray, memSize, cudaMemcpyHostToDevice);
    TestDevice <<< 4, 4 >>> (deviceArray);
    cudaMemcpy(hostArray, deviceArray, memSize, cudaMemcpyDeviceToHost);

    std::cout << "After device\n";
    for(int i=0;i<arrayLength;i++)
    {
        std::cout << hostArray[i] << "\n";
    }

    cudaFree(deviceArray);
    free(hostArray);

    std::cout << "Done\n";
}

#endif

MyKernel.cu

MyKernel.cu

#ifndef _MY_KERNEL_
#define _MY_KERNEL_

__global__ void TestDevice(int *deviceArray)
{
    int idx = blockIdx.x*blockDim.x + threadIdx.x;
    deviceArray[idx] = deviceArray[idx]*deviceArray[idx];
}


#endif

生成日志：

1>------ Build started: Project: CUDASandbox, Configuration: Debug x64 ------
1>Compiling with CUDA Build Rule...
1>"C:\CUDA\bin64\nvcc.exe"    -arch sm_10 -ccbin "C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\bin"    -Xcompiler "/EHsc /W3 /nologo /O2 /Zi   /MT  "  -maxrregcount=32  --compile -o "x64\Debug\KernelSupport.cu.obj" "d:\Stuff\Programming\Visual Studio 2008\Projects\CUDASandbox\CUDASandbox\KernelSupport.cu" 
1>KernelSupport.cu
1>tmpxft_000016f4_00000000-3_KernelSupport.cudafe1.gpu
1>tmpxft_000016f4_00000000-8_KernelSupport.cudafe2.gpu
1>tmpxft_000016f4_00000000-3_KernelSupport.cudafe1.cpp
1>tmpxft_000016f4_00000000-12_KernelSupport.ii
1>Linking...
1>KernelSupport.cu.obj : error LNK2005: __device_stub__Z10TestDevicePi already defined in MyKernel.cu.obj
1>KernelSupport.cu.obj : error LNK2005: "void __cdecl TestDevice__entry(int *)" (?TestDevice__entry@@YAXPEAH@Z) already defined in MyKernel.cu.obj
1>D:\Stuff\Programming\Visual Studio 2008\Projects\CUDASandbox\x64\Debug\CUDASandbox.exe : fatal error LNK1169: one or more multiply defined symbols found
1>Build log was saved at "file://d:\Stuff\Programming\Visual Studio 2008\Projects\CUDASandbox\CUDASandbox\x64\Debug\BuildLog.htm"
1>CUDASandbox - 3 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

我在Windows 7 64位运行Visual Studio 2008。

I am running Visual Studio 2008 on Windows 7 64bit.

编辑：

我想我需要详细阐述了这点。最终的结果我找了这里是有像Main.cpp的使用 INT的main（）事件正常的C ++应用程序，并有东西从那里运行。在某些码在我的.cpp code点我希望能够引用CUDA位。所以我的想法（和纠正我，如果这里有一个更标准约定）是我会把CUDA内核code到他们的.CU文件，然后有一个配套文件.CU将采取谈话的护理设备和调用内核函数，什么不是。

I think I need to elaborate on this a little bit. The end result I am looking for here is to have a normal C++ application with something like Main.cpp with the int main() event and have things run from there. At certains point in my .cpp code I want to be able to reference CUDA bits. So my thinking (and correct me if there a more standard convention here) is that I will put the CUDA Kernel code into their on .cu files, and then have a supporting .cu file that will take care of talking to the device and calling kernel functions and what not.

推荐答案

您包括 mykernel.cu 在 kernelsupport.cu ，当您尝试编译链接看到mykernel.cu两次。你必须创建定义为TestDevice头和包括替代。

You are including mykernel.cu in kernelsupport.cu, when you try to link the compiler sees mykernel.cu twice. You'll have to create a header defining TestDevice and include that instead.

再评论：

像这样的东西应该工作

// MyKernel.h
#ifndef mykernel_h
#define mykernel_h
__global__ void TestDevice(int* devicearray);
#endif

和则包括文件改为

//KernelSupport.cu
#ifndef _KERNEL_SUPPORT_
#define _KERNEL_SUPPORT_

#include <iostream>
#include <MyKernel.h>
// ...

重新您的编辑

只要你在C code使用没有任何CUDA具体的东西头（ __内核__ ， __全球__ 等），你应该罚款链接C ++和CUDA code。

As long as the header you use in c++ code doesn't have any cuda specific stuff (__kernel__,__global__, etc) you should be fine linking c++ and cuda code.

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