好了，问题来了：
使用CUDA 1.1计算GPU，我试图为每个线程维护一组索引（可能数量不同，这里固定为4个），我将其作为结构变量的成员保留。
我的问题是，当访问成员数组时，获取对结构体的引用会导致错误的结果：我用0初始化成员数组值，当我使用原始结构变量读取数组值时，我得到正确的值（0），但当我使用对结构变量的引用读取它时，我得到垃圾（-8193）。即使使用class而不是struct，也会发生这种情况。
为什么tmp小于/不等于0？
C++不是我的主要语言，所以这可能是一个概念问题，也可能是在CUDA中工作的一个怪癖。

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
}