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Host侧代码与说明

以vadd算子为例,计算时,可将两个类型为float的tensor逐元素相加,每个tensor包含64个元素,数据类型为float。

首先在Host侧给两个入参以及结果创建空间并赋初始值,其次在Device侧创建参数指针并分配空间,再将初始值拷贝到Device中就可以拉起Device侧的核函数,Device侧代码与说明包含了函数的具体实现。

Device执行结束后可以将结果从Device侧拷贝到Host侧并与CPU执行结果相对比,最后释放空间与数据流即可。
// Host侧文件:main.cce
// 直接通过<<<>>>异构调用语法调用Device侧kernel
#include "acl/acl.h"
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define NUM 64

// 向量初始化函数
void InitVector(float *vector, uint32_t len, float min_value, float max_value) {
    float range = max_value - min_value;
    
    for (uint32_t i = 0; i < len; i++) {
        float random_value = (float)rand() / (float)RAND_MAX;
        vector[i] = min_value + random_value * range;
    }
}

// 向量相加函数,用于在Host侧计算结果,后续和Device侧对比
void vector_add(float *a, float *b, float *result, uint32_t len) {
    for (uint32_t i = 0; i < len; i++) {
        result[i] = a[i] + b[i];
    }
}

// 判断两个向量是否相等函数,用于验证Device侧结果的正确性
bool are_vectors_equal(float *vec1, float *vec2, uint32_t len) {
    for (uint32_t i = 0; i < len; i++) {
        if (fabs(vec1[i] - vec2[i]) > 1) {
            return false;
        }
    }
    return true; 
}

extern "C" __global__ [aicore] void add_kernel(__gm__ uint8_t * __restrict tensor_a, __gm__ uint8_t * __restrict tensor_b, __gm__ uint8_t * __restrict tensor_c);

int main() {
    aclrtSetDevice(0);
    aclrtStream stream;
    aclrtCreateStream(&stream);

    // Host侧数据处理
    float tensor_a[NUM] = {1.0};
    float tensor_b[NUM] = {1.0};
    float tensor_c[NUM] = {0.0};
    InitVector((float *)tensor_a, NUM, -5, 5);
    InitVector((float *)tensor_b, NUM, -5, 5);
    InitVector((float *)tensor_c, NUM, -5, 5);

    // 计算Host侧的golden输出
    float golden[NUM] = {0.0};
    vector_add(tensor_a, tensor_b, golden, NUM);
    
    // 在Device上分配内存,aclrtMalloc分配的是原始字节内存,不包含任何类型信息,在Device侧核函数中需要以正确类型解释这些内存区域
    __gm__ uint8_t *tensor_aGm = nullptr;
    __gm__ uint8_t *tensor_bGm = nullptr;
    __gm__ void *tensor_aGm_void;
    aclrtMalloc(&tensor_aGm_void, sizeof(tensor_a), ACL_MEM_MALLOC_NORMAL_ONLY);
    tensor_aGm = reinterpret_cast<__gm__ unsigned char *>(tensor_aGm_void);
    __gm__ void *tensor_bGm_void;
    aclrtMalloc(&tensor_bGm_void, sizeof(tensor_b), ACL_MEM_MALLOC_NORMAL_ONLY);
    tensor_bGm = reinterpret_cast<__gm__ unsigned char *>(tensor_bGm_void);
    __gm__ uint8_t *tensor_cGm = nullptr;
    __gm__ void *tensor_cGm_void;
    aclrtMalloc(&tensor_cGm_void, sizeof(tensor_c), ACL_MEM_MALLOC_NORMAL_ONLY);
    tensor_cGm = reinterpret_cast<__gm__ unsigned char *>(tensor_cGm_void);

    // 将Host侧数据拷贝到Device侧
    aclrtMemcpyAsync((void *)tensor_aGm, sizeof(tensor_a), (float *)tensor_a, sizeof(tensor_a), ACL_MEMCPY_HOST_TO_DEVICE, stream);
    aclrtMemcpyAsync((void *)tensor_bGm, sizeof(tensor_b), (float *)tensor_b, sizeof(tensor_b), ACL_MEMCPY_HOST_TO_DEVICE, stream);
    aclrtMemcpyAsync((void *)tensor_cGm, sizeof(tensor_c), (void *)tensor_c, sizeof(tensor_c), ACL_MEMCPY_HOST_TO_DEVICE, stream);

    // 启动Device侧核函数
    add_kernel<<<1, nullptr, stream>>>(tensor_aGm, tensor_bGm, tensor_cGm);
    
    // 获取Device执行结果,并拷贝到Host
    aclrtMemcpyAsync((void *)tensor_c, sizeof(tensor_c), tensor_cGm,
                     sizeof(tensor_c), ACL_MEMCPY_DEVICE_TO_HOST, stream);
    aclrtSynchronizeStream(stream);

    // 打印Host侧计算的golden输出和Device侧计算的输出,将float转换为int类型便于观察
    for (int i = 0; i < NUM; i++) {
        printf("%4d", (int)golden[i]);      
    }
    printf("\n");
    for (int i = 0; i < NUM; i++) {
        printf("%4d", (int)tensor_c[i]);      
    }
    printf("\n");
    
    // 判断Device侧的计算结果是否正确
    bool equal1 = are_vectors_equal(golden, tensor_c, NUM);
    printf("Matrix golden and Matrix tensor_c are %s\n", equal1 ? "equal" : "not equal");

    // 释放数据空间以及数据流
    aclrtFree(tensor_aGm);
    aclrtFree(tensor_bGm);
    aclrtFree(tensor_cGm);
    aclrtDestroyStream(stream);
    aclrtResetDevice(0);
}