C++和CUDA:为什么代码每次返回不同的结果

更新：我发现了错误。由于我之前发布的代码非常复杂，我简化了它们，只在问题出现时保留部分。

if (number >= dim * num_points)
return;

但实际上，我只有num_points，我想使用num_point线程，所以正确的方法应该是

if (number >= num_points)
return;

谢谢大家的帮助。

我正在将一些C++代码从CPU重写到GPU。代码粘贴在下面。抱歉时间太长了，因为我认为用这种方式更容易发现问题。

在代码中，对于每个线程，我都需要一些矩阵格式的中间结果，所以我为这些中间结果分配设备内存，例如d_dir2、d_R、d_Stick、d_PStick。结果并不是我所期望的，所以为了调试，我尝试以这种方式输出一些中间结果R：

如果(k==0){结果[tmp_int1+i*dim+j]＝R[tmp_int1+i*dim+j]；}

以及以后在C++中，我打印结果。然而，我发现每次的结果都会给出不同的值。有时它给出正确答案R，有时，PStick的值，有时R和PStick组合，有时R与0的组合(结果在开始时初始化为0)。

我很困惑是什么引起了这个问题。知道吗？非常感谢：)

__global__ void stickvote(const int dim, const int num_points, const int gridx, float Sigma, float* input, float* dir2, float* R, float* Stick, float* PStick, float* results) {
float threshold = 4 * Sigma;
float c = (- 16 * log(0.1f) * (sqrt(Sigma) - 1)) / 3.1415926f / 3.1415926f;
int row = blockIdx.y * blockDim.y + threadIdx.y;
int col = blockIdx.x * blockDim.x + threadIdx.x;
int number = row * BLOCK_SIZE * gridx + col;
if (number >= dim * num_points)  //// The bug is here!
return;
}

extern "C" void KernelStickVote(int dim, int num_points, float Sigma, float* input, float* results) {
const int totalpoints = num_points;
const int totalpoints_input = (dim + 1)* (dim + 1) * num_points;
const int totalpoints_output = dim * dim * num_points;
size_t size_input = totalpoints_input * sizeof(float);
size_t size_output = totalpoints_output * sizeof(float);
float* d_input;
cutilSafeCall(cudaMalloc((void**)&d_input, size_input));
float* d_result;
cutilSafeCall(cudaMalloc((void**)&d_result, size_output));
// used to save dir, and calculate dir * dir'
float* d_dir2;
cutilSafeCall(cudaMalloc((void**)&d_dir2, dim * num_points * sizeof(float)));
// used to save R: dim * dim * N
float* d_R;
cutilSafeCall(cudaMalloc((void**)&d_R, size_output));
// used to save Stick: dim * dim * N
float* d_Stick;
cutilSafeCall(cudaMalloc((void**)&d_Stick, size_output));
// used to save Stick: dim * dim * N
float* d_PStick;
cutilSafeCall(cudaMalloc((void**)&d_PStick, size_output));
// Copy input data from host to device
cudaMemcpy(d_input, input, size_input, cudaMemcpyHostToDevice);
int totalblock = (totalpoints % BLOCKPOINTS==0 ? totalpoints/BLOCKPOINTS : (int(totalpoints/BLOCKPOINTS) + 1));
int gridx = (65535 < totalblock ? 65535 : totalblock);
int gridy = (totalblock % gridx == 0 ? totalblock/gridx : (int(totalblock/gridx)+1) );
dim3 dimBlock(BLOCK_SIZE, BLOCK_SIZE);
dim3 dimGrid(gridx, gridy);
stickvote<<<dimGrid, dimBlock>>>(dim, num_points, gridx, Sigma, d_input, d_dir2, d_R, d_Stick, d_PStick, d_result);
cudaMemcpy(results, d_result, size_output, cudaMemcpyDeviceToHost);
cudaFree(d_input);
cudaFree(d_result);
cudaFree(d_dir2);
cudaFree(d_R);
cudaFree(d_Stick);
cudaFree(d_PStick);
}