chapter5_2_add_block copy.cu

#include <cuda_runtime.h>
#include <device_launch_parameters.h>
#include <stdio.h>
#define N (33*1024)

__global__ void add(int* a, int* b, int* c) {
	int tid = threadIdx.x+blockIdx.x*blockDim.x;
	while (tid < N) {
		c[tid] = a[tid] + b[tid];
		tid += blockDim.x * gridDim.x;
	}
	
}
int main() {
	int a[N], b[N], c[N];
	for (int i = 0; i < N; i++) {
		a[i] = i;
		b[i] = i * i;
	}
	int* dev_a, * dev_b, * dev_c;
	cudaMalloc((void**)&dev_a, sizeof(int) * N);
	cudaMalloc((void**)&dev_b, sizeof(int) * N);
	cudaMalloc((void**)&dev_c, sizeof(int) * N);
	cudaMemcpy(dev_a, a, sizeof(int) * N, cudaMemcpyHostToDevice);
	cudaMemcpy(dev_b, b, sizeof(int) * N, cudaMemcpyHostToDevice);
	add << <256, 256 >> > (dev_a, dev_b, dev_c);
	cudaMemcpy(c, dev_c, sizeof(int) * N, cudaMemcpyDeviceToHost);
	for (int i = 0; i < N; i++) {
		printf("%d + %d = %d\n", a[i], b[i], c[i]);
	}
	cudaFree(dev_a);
	cudaFree(dev_b);
	cudaFree(dev_c);
}