最近，需要在kernel函数中调用浮点型的随机数。于是上网搜了下相关资料，一种方式是自己手动写一个随机数的__device__函数，然后在调用的时候调用这个函数。另一种，原来cuda在toolkit中给出了实现方式。
首先要用到三个函数：
代码语言：javascript复制curandCreateGenerator(&gen,CURAND_RNG_PSEUDO_DEFAULT); 指定触发器为gen，随机方式为CURAND_RNG_PSEUDO_DEFAULT
代码语言：javascript复制curandSetPseudoRandomGeneratorSeed(gen,1234ULL);指定种子为1234ULL(不同的种子产生的随机数列是不一样的)
代码语言：javascript复制curandGenerateUniform(gen,devData,n);根据触发器gen，输出目标指针为devData，规模大小为n
代码语言：javascript复制/*
* 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:%dn",__FILE__,__LINE__);
return EXIT_FAILURE;}} while(0)
#define CURAND_CALL(x) do { if((x)!=CURAND_STATUS_SUCCESS) {
printf("Error at %s:%dn",__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）
