GPU/CUDA程序初体验 向量加法
https://www.cnblogs.com/xudong-bupt/p/3461163.html
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#include <stdio.h>#include<cuda_runtime.h>//__global__声明的函数，告诉编译器这段代码交由CPU调用，由GPU执行__global__ void add(const int *dev_a,const int *dev_b,int *dev_c){ int i=threadIdx.x; dev_c[i]=dev_a[i]+dev_b[i];}int main(void){ //申请主机内存，并进行初始化 int host_a[512],host_b[512],host_c[512]; for(int i=0;i<512;i++) { host_a[i]=i; host_b[i]=i<<1; } //定义cudaError，默认为cudaSuccess(0) cudaError_t err = cudaSuccess; //申请GPU存储空间 int *dev_a,*dev_b,*dev_c; err=cudaMalloc((void **)&dev_a, sizeof(int)*512); err=cudaMalloc((void **)&dev_b, sizeof(int)*512); err=cudaMalloc((void **)&dev_c, sizeof(int)*512); if(err!=cudaSuccess) { printf("the cudaMalloc on GPU is failed"); return 1; } printf("SUCCESS"); //将要计算的数据使用cudaMemcpy传送到GPU cudaMemcpy(dev_a,host_a,sizeof(host_a),cudaMemcpyHostToDevice); cudaMemcpy(dev_b,host_b,sizeof(host_b),cudaMemcpyHostToDevice); //调用核函数在GPU上执行。数据较少，之使用一个Block，含有512个线程 add<<<1,512>>>(dev_a,dev_b,dev_c); cudaMemcpy(&host_c,dev_c,sizeof(host_c),cudaMemcpyDeviceToHost); for(int i=0;i<512;i++) printf("host_a[%d] + host_b[%d] = %d + %d = %d\n",i,i,host_a[i],host_b[i],host_c[i]); cudaFree(dev_a);//释放GPU内存 cudaFree(dev_b);//释放GPU内存 cudaFree(dev_c);//释放GPU内存 return 0 ;} |
