CUDA：struct的共享数据成员和该struct的引用成员具有不同的地址，值

Question

接下来是问题：使用CUDA 1.1计算gpu，我试图为每个线程维护一组（可能不同数量，这里固定为4）索引，这是我作为struct var成员保留的引用。我的问题是获取对结构的引用然后在访问成员数组时导致不正确的结果：我初始化成员数组值为0，当我使用原始struct var读取数组val时，我得到正确的值（0），但是当我使用struct var的引用读取它时，我得到了垃圾（-8193）。即使使用类而不是结构，也会发生这种情况。

为什么tmp低于！= 0 ??

c ++不是我的主要语言，所以这可能是一个概念问题，或者它可能是在cuda工作的怪癖

struct DataIdx {
    int numFeats;
    int* featIdx;
};
extern __shared__ int sharedData[];

__global__  void myFn(){
    int tidx = blockIdx.x * blockDim.x + threadIdx.x;

    DataIdx myIdx;  //instantiate the struct var in the context of the current thread
    myIdx.numFeats = 4;
    size_t idxArraySize = sizeof(int)*4;
    //get a reference to my array for this thread. Parallel Nsight debugger shows myIdx.featIdx address = 0x0000000000000000e0
    myIdx.featIdx = (int*)(&sharedData[tidx*idxArraySize]);  

    myIdx.featIdx[0] = 0x0;  //set first value to 0 
    int tmp = myIdx.featIdx[0];  // tmp is correctly eq to 0 in Nsight debugger -- As Expected!!
    tmp = 2*tmp;    antIdx.featIdx[0] = tmp; //ensure compiler doesn't elide out tmp

    DataIdx *tmpIdx = &myIdx;  //create a reference to my struct var
    tmp = tmpIdx.featIdx[0];   // expected 0, but tmp = -8193 in debugger !! why?  debugger shows address of tmpIdx.featIdx = __devicea__ address=8
    tmpIdx.featIdx[0] = 0x0;
    tmp = tmpIdx.featIdx[0]; // tmp = -1; cant even read what we just set

    //forcing the same reference as myIdx.featIdx, still gives a problem! debugger shows address of tmpIdx.featIdx = __devicea__ address=8
    tmpIdx->featIdx =  (int*)(&sharedData[tidx*idxArraySize]); 
    tmp = tmpIdx.featIdx[0]; //tmp = -8193!! why != 0?

    DataIdx tmpIdxAlias = myIdx;
    tmp = tmpIdx.featIdx[0]; //aliasing the original var gives correct results, tmp=0


     myIdx.featIdx[0] = 0x0;
     mySubfn(&myIdx); //this is a problem because it happens when passing the struct by reference to subfns
     mySubfn2(myIdx);
}
__device__ mySubfn(struct DataIdx *myIdx){
  int tmp = myIdx->featIdx[0]; //tmp == -8193!! should be 0
}
__device__ mySubfn2(struct DataIdx &myIdx){
  int tmp = myIdx.featIdx[0]; //tmp == -8193!! should be 0
}