如何在cuda内核函数中产生随机数（host端调用，device端产生）

最近，须要在kernel函数中调用浮点型的随机数。因而上网搜了下相关资料，一种方式是本身手动写一个随机数的__device__函数，而后在调用的时候调用这个函数。另外一种，原来cuda在toolkit中给出了实现方式。

 

首先要用到三个函数：

curandCreateGenerator(&gen,CURAND_RNG_PSEUDO_DEFAULT);

指定触发器为gen，随机方式为CURAND_RNG_PSEUDO_DEFAULT

curandSetPseudoRandomGeneratorSeed(gen,1234ULL);

指定种子为1234ULL(不一样的种子产生的随机数列是不同的)

curandGenerateUniform(gen,devData,n);

根据触发器gen，输出目标指针为devData，规模大小为n

/* * This program uses the host CURAND API to generate 100 * pseudorandom floats. */ #include <stdio.h> #include <stdlib.h> #include <cuda.h> #include <curand.h>

#define CUDA_CALL(x) do { if((x)!=cudaSuccess) { \ printf("Error at %s:%d\n",__FILE__,__LINE__);\ return EXIT_FAILURE;}} while(0) #define CURAND_CALL(x) do { if((x)!=CURAND_STATUS_SUCCESS) { \ printf("Error at %s:%d\n",__FILE__,__LINE__);\ return EXIT_FAILURE;}} while(0) int main(int argc, char *argv[]) { size_t n = 100; size_t i; curandGenerator_t gen; float *devData, *hostData; /* Allocate n floats on host */ hostData = (float *)calloc(n, sizeof(float)); /* Allocate n floats on device */ CUDA_CALL(cudaMalloc((void **)&devData, n*sizeof(float))); /* Create pseudo-random number generator */ CURAND_CALL(curandCreateGenerator(&gen, CURAND_RNG_PSEUDO_DEFAULT)); /* Set seed */ CURAND_CALL(curandSetPseudoRandomGeneratorSeed(gen, 1234ULL)); /* Generate n floats on device */ CURAND_CALL(curandGenerateUniform(gen, devData, n)); /* Copy device memory to host */ CUDA_CALL(cudaMemcpy(hostData, devData, n * sizeof(float), cudaMemcpyDeviceToHost)); /* Show result */
    for(i = 0; i < n; i++) { printf("%1.4f ", hostData[i]); } printf("\n"); /* Cleanup */ CURAND_CALL(curandDestroyGenerator(gen)); CUDA_CALL(cudaFree(devData)); free(hostData); return EXIT_SUCCESS; }

样例输出后，产生的结果为：（待补）