chapter4_2.cu

#include <iostream>
#include <cuda_runtime.h>
#include <device_launch_parameters.h>
#define N 100
__global__ void add(int* a, int* b, int* c) {
	int tid = blockIdx.x;
	if (tid < N) {
		c[tid] = a[tid] + b[tid];
	}
}
int main() {
	int a[N], b[N], c[N];
	int* dev_a, * dev_b, * dev_c;
	cudaMalloc((void**)&dev_a, N * sizeof(int));
	cudaMalloc((void**)&dev_b, N * sizeof(int));
	cudaMalloc((void**)&dev_c, N * sizeof(int));
	for (int i = 0; i < N; i++) {
		a[i] = -i;
		b[i] = i * i;
	}
	cudaMemcpy(dev_a, a, N * sizeof(int),cudaMemcpyHostToDevice);
	cudaMemcpy(dev_b, b, N * sizeof(int), cudaMemcpyHostToDevice);
	add << <N, 1 >> > (dev_a, dev_b, dev_c);
	cudaMemcpy(c, dev_c, N * sizeof(int), 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);
}