如何获得唯一标识符

如果block只有一维
blockDim.x表示block的总数，
blockIdx.x 表示当前是第几个block

  1. #include<stdio.h>
  2. __global__ void cuda_hello(void)
  3. {
  4.     int bid = blockIdx.x;
  5.     int tid = threadIdx.x;
  6.     int idx = bid*blockDim.x+tid;
  7.     printf("idx:[%d], bid:[%d], tid:[%d] Hello World from GPU!\n",idx,bid, tid);
  8. }
  10. int main() 
  11. {
  12.     int numOfBlocks = 5;
  13.     int numOfThreads = 3;
  14.     cuda_hello<<<numOfBlocks , numOfThreads>>>();
  15.     cudaDeviceReset();
  16.     return 0;
  17. }
  1. #include<stdio.h>
  2. __global__ void narcissistic_and_four_leaf_rose_numbers_gpu(void)
  3. {
  4.     // ToDo
  5.    int bid = blockIdx.x;
  6.    int tid = threadIdx.x;
  7.    int idx = bid*blockDim.x+tid;
  8.    if (idx>=100&&idx<10000){
  9.       int tho, hun, ten, ind,i;
  10.       i = idx;
  11.       tho = i/1000;
  12.       hun = i/100;
  13.       ten = (i-hun*100)/10;
  14.       ind = i%10;
  15.       if(tho>0)
  16.       {
  17.           hun=(i-tho*1000)/100;
  18.           ten=(i-tho*1000-hun*100)/10;
  19.           ind=i%10;
  20.           if(i==tho*tho*tho*tho + hun*hun*hun*hun + ten*ten*ten*ten + ind*ind*ind*ind)
  21.           {
  22.               printf("%d  ", i);
  23.           }
  24.       }
  25.       else
  26.       {
  27.           if(i==hun*hun*hun + ten*ten*ten + ind*ind*ind)
  28.           {
  29.               printf("%d  ", i);
  30.           }
  31.       }
  32.    }
  33. }
  35. void narcissistic_and_four_leaf_rose_numbers_cpu(int x1, int x2)
  36. {
  37.     int tho, hun, ten, ind;
  38.     for(int i=x1; i<x2; i++)
  39.     {
  40.         tho = i/1000;
  41.         hun = i/100;
  42.         ten = (i-hun*100)/10;
  43.         ind = i%10;
  44.         if(tho>0)
  45.         {
  46.             hun=(i-tho*1000)/100;
  47.             ten=(i-tho*1000-hun*100)/10;
  48.             ind=i%10;
  49.             if(i==tho*tho*tho*tho + hun*hun*hun*hun + ten*ten*ten*ten + ind*ind*ind*ind)
  50.             {
  51.                 printf("%d  ", i);
  52.             }
  53.         }
  54.         else
  55.         {
  56.             if(i==hun*hun*hun + ten*ten*ten + ind*ind*ind)
  57.             {
  58.                 printf("%d  ", i);
  59.             }
  60.         }
  61.     }
  62. }
  64. int main() 
  65. {
  66.     int numLowerBound = 100;
  67.     int numUpperBound = 10000;
  68.     printf("Narcissistic and four-leaf rose numbers from %d to %d (CPU version):\n", numLowerBound, numUpperBound);
  69.     narcissistic_and_four_leaf_rose_numbers_cpu(numLowerBound, numUpperBound);
  70.     printf("\nNarcissistic and four-leaf rose numbers from %d to %d (GPU version):\n", numLowerBound, numUpperBound);
  71.     // ToDo (Tip: call the function narcissistic_and_four_leaf_rose_numbers_gpu)
  72.     narcissistic_and_four_leaf_rose_numbers_gpu<<<10,1024>>>();
  73.     cudaDeviceReset();
  74.     return 0;
  75. }