CUDA第一个程序优化二（有线程块）

#include <stdio.h>
#include <cuda_runtime.h>
#include<stdlib.h>
#define TOTAL_NUM 50000
#define Thread_num 500
#define Block_num 20
bool CUDA_initial(void)
{
 int i;
 int device_count;
 if( cudaGetDeviceCount(&device_count) )
 {
  printf(" There is zero device beyond 1.0/n");
  return false;
 }
 else
  printf("There is %d device beyond 1.0/n",device_count);
 for(i=0;i<device_count;i++)
 {
  struct cudaDeviceProp device_prop;
  if(cudaGetDeviceProperties(&device_prop,i)==cudaSuccess)
  {
   printf("device properties is :/n"
      "/t device name is %s/n"
      "/t totalGlobalMem is %d/n"
      "/t sharedMemPerBlock is %d/n"
      "/t regsPerBlock is %d/n"
      "/t warpSize is %d/n"
      "/t memPitch is %d/n"
      "/t maxThreadsPerBlock is %d/n"
      "/t maxThreadsDim [3] is %d X %d X %d/n"
      "/t maxGridSize [3] is %d X %d X %d/n"
      "/t totalConstMem is %d/n"
      "/t device version is major %d ,minor %d/n"
      "/t clockRate is %d/n"
      "/t textureAlignment is %d/n"
      "/t deviceOverlap is %d/n"
      "/t multiProcessorCount is %d/n",
      device_prop.name,
      device_prop.totalGlobalMem,
      device_prop.sharedMemPerBlock,
      device_prop.regsPerBlock,
      device_prop.warpSize,
      device_prop.memPitch,
      device_prop.maxThreadsPerBlock,
      device_prop.maxThreadsDim[0],device_prop.maxThreadsDim[1],device_prop.maxThreadsDim[2],
      device_prop.maxGridSize[0],device_prop.maxGridSize[1],device_prop.maxGridSize[2],
      device_prop.totalConstMem,
      device_prop.major,device_prop.minor,
      device_prop.clockRate,
      device_prop.textureAlignment,
      device_prop.deviceOverlap,
      device_prop.multiProcessorCount);
   break;
  }
 }
 
 if(i==device_count)
 {
  printf("Get the propertites of device occurred error/n");
  return false;
 }

 if(cudaSetDevice(i)==cudaErrorInvalidDevice)
 {
  printf("Set Device occurred error/n");
  return false;
 }

 return true;
}

void generate_num(int *num,int data_num)
{
 int i;
 for(i=0;i<data_num;i++)
 {
  *(num+i)=rand()%10;
 }
}

/*********************************time test*************************************/
 class TimeCounter{
                protected :
                        clock_t startp,endp;
                public :
                        TimeCounter():startp(-1),endp(-1){}
                        void start(){//设置计时起点
                        #ifdef __CUDACC__
                                cudaThreadSynchronize();
                        #endif
                                startp=clock();
                        }
                        void stop(){//设置计时终点
                                if(-1==startp){
                                        perror("you must set start point at first");
                                }else{
                                #ifdef __CUDACC__
                                        cudaThreadSynchronize();
                                #endif
                                        endp=clock();
                                }
                        }
                        virtual long getTimeDiff()=0;//返回时间差滴答数
                        virtual void printTimeDiff()=0;//打印出时间差
        };
        class MillisecondCounter:public TimeCounter{
                public :
                    long getTimeDiff(){

                                 if(-1==endp){
                                        perror("you must set stop point before invoke this function");
                                        exit(1);
                                }else{
                                        return 1.0f*(endp-startp)/CLOCKS_PER_SEC*1000;
                                }
                        }
                        void printTimeDiff(){
                                long temp=getTimeDiff();
                                printf("use time :%ldms/n",temp);
                        }
        };
#ifdef __CUDACC__
class MicrosecondCounter:public TimeCounter{
                public:
                        long getTimeDiff(){
                                if(-1==endp){
                                        printf("please set start point or end point/n");
                                        exit(1);
                                }else{
                                return 1.0f*(endp-startp)/CLOCKS_PER_SEC*1000000;
                                }
                        }
                        void printTimeDiff(){
                                long temp=getTimeDiff();
                                printf("use time:%ld us/n",temp);
                        }
        };
#endif
/****************time test end ************************/

 

__global__ void square_sum(int *num,int num_of_num,int *result,clock_t *time)
{
 int i;
 int sum=0;
 const int thread_idx=threadIdx.x;
 const int block_idx=blockIdx.x;
 extern __shared__  int sum_in_thread[];
 clock_t start;
 if((thread_idx==0)&&(block_idx==0)) start=clock();

 sum_in_thread[thread_idx]=0;
 for(i=block_idx*Thread_num+thread_idx;i<TOTAL_NUM;i +=Thread_num*Block_num)
  sum_in_thread[thread_idx]+=num[i]*num[i];
 __syncthreads();

 if(thread_idx==0)
 {
  for(i=1;i<Thread_num;i++)
  {
   sum_in_thread[0]+=sum_in_thread[i];
  }
  *(result+block_idx)=sum_in_thread[0];
 }
 
 if((thread_idx==0)&&(block_idx==0)) *time=clock()-start;
}

int main()
{
 int i;
 MicrosecondCounter mc;
    TimeCounter& tc = mc;
 if(CUDA_initial()==true)
  printf("CUDA initial successed!/n");
 int num_str[TOTAL_NUM];
 generate_num(num_str,TOTAL_NUM);
 int *gpudata;
    int *result;
 clock_t *time;
 cudaMalloc((void **)&gpudata,sizeof(int)*TOTAL_NUM);
 cudaMalloc((void **)&result,sizeof(int)*Block_num);
 cudaMalloc((void **)&time,sizeof(clock_t));

 cudaMemcpy((void *)gpudata,num_str,sizeof(int)*TOTAL_NUM,cudaMemcpyHostToDevice);
 
 square_sum<<<Block_num,Thread_num,Thread_num*sizeof(int)>>>(gpudata,TOTAL_NUM,result,time);

//这里一定要分配共享存储器的大小

 int result_in_GPU=0;
 clock_t time_used;
 int sum_GPU[Block_num];
 cudaMemcpy((void *)&time_used,time,sizeof(clock_t),cudaMemcpyDeviceToHost);
 cudaMemcpy((void *)sum_GPU,result,sizeof(int)*Block_num,cudaMemcpyDeviceToHost);
 for(i=0;i<Block_num;i++)
  result_in_GPU+=sum_GPU[i];
 printf("In GPU result is %d/n",result_in_GPU);
 printf("In GPU time used is %d/n",time_used);

 int result_in_CPU=0;
 
 for(i=0;i<TOTAL_NUM;i++)
 {
  result_in_CPU+=num_str[i]*num_str[i];
 }
 printf("In CPU result is %d/n",result_in_CPU);
 cudaFree(gpudata);
 cudaFree(result);
 cudaFree(time);
 return 0;
}