+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include <assert.h>
+#include "cutil_inline.h"
+
+const int nbThreadsPerBloc=256;
+
+__global__
+void addition(int size, int *d_C, int *d_A, int *d_B) {
+ int tid = blockIdx.x * blockDim.x + threadIdx.x;
+ if(tid<size) {
+ d_C[tid]=d_A[tid]+d_B[tid];
+ }
+}
+
+
+int main( int argc, char** argv)
+{
+
+ if(argc!=2) {
+ printf("usage: ex1 nb_components\n");
+ exit(0);
+ }
+
+
+
+ int size=atoi(argv[1]);
+
+ int i;
+ int *h_arrayA=(int*)malloc(size*sizeof(int));
+ int *h_arrayB=(int*)malloc(size*sizeof(int));
+ int *h_arrayC=(int*)malloc(size*sizeof(int));
+ int *h_arrayCgpu=(int*)malloc(size*sizeof(int));
+ int *d_arrayA, *d_arrayB, *d_arrayC;
+
+
+ cudaMalloc((void**)&d_arrayA,size*sizeof(int));
+ cudaMalloc((void**)&d_arrayB,size*sizeof(int));
+ cudaMalloc((void**)&d_arrayC,size*sizeof(int));
+
+ for(i=0;i<size;i++) {
+ h_arrayA[i]=i;
+ h_arrayB[i]=2*i;
+ }
+
+
+ unsigned int timer_cpu = 0;
+ cutilCheckError(cutCreateTimer(&timer_cpu));
+ cutilCheckError(cutStartTimer(timer_cpu));
+ for(i=0;i<size;i++) {
+ h_arrayC[i]=h_arrayA[i]+h_arrayB[i];
+ }
+ cutilCheckError(cutStopTimer(timer_cpu));
+ printf("CPU processing time : %f (ms) \n", cutGetTimerValue(timer_cpu));
+ cutDeleteTimer(timer_cpu);
+
+
+ unsigned int timer_gpu = 0;
+ cutilCheckError(cutCreateTimer(&timer_gpu));
+ cutilCheckError(cutStartTimer(timer_gpu));
+ cudaMemcpy(d_arrayA,h_arrayA, size * sizeof(int), cudaMemcpyHostToDevice);
+ cudaMemcpy(d_arrayB,h_arrayB, size * sizeof(int), cudaMemcpyHostToDevice);
+
+
+
+
+ int nbBlocs=(size+nbThreadsPerBloc-1)/nbThreadsPerBloc;
+
+ addition<<<nbBlocs,nbThreadsPerBloc>>>(size,d_arrayC,d_arrayA,d_arrayB);
+
+ cudaMemcpy(h_arrayCgpu,d_arrayC, size * sizeof(int), cudaMemcpyDeviceToHost);
+
+ cutilCheckError(cutStopTimer(timer_gpu));
+ printf("GPU processing time : %f (ms) \n", cutGetTimerValue(timer_gpu));
+ cutDeleteTimer(timer_gpu);
+
+ for(i=0;i<size;i++)
+ assert(h_arrayC[i]==h_arrayCgpu[i]);
+
+ cudaFree(d_arrayA);
+ cudaFree(d_arrayB);
+ cudaFree(d_arrayC);
+ free(h_arrayA);
+ free(h_arrayB);
+ free(h_arrayC);
+
+
+ return 0;
+
+}
