//填充随机数
static void fill_random_value(std::vector<float>& vec_data)
{std::uniform_real_distribution<float> distribution(std::numeric_limits<float>::min(),std::numeric_limits<float>::max());std::default_random_engine generator;std::generate(vec_data.begin(), vec_data.end(), [&]() { return distribution(generator); });
}
//判断两个vector是否相等
static bool is_equals_vector(const std::vector<float>& vec_a,const std::vector<float>& vec_b)
{if (vec_a.size() != vec_b.size()){return false;}for (size_t i = 0; i < vec_a.size(); i++){if (vec_a[i] != vec_b[i]){return false;}}return true;
}
//正常的vector相乘 （注意：需要关闭编译器的自动向量化优化）
static void normal_vector_mul(const std::vector<float>& vec_a,const std::vector<float>& vec_b,std::vector<float>& vec_result)
{assert(vec_a.size() == vec_b.size());assert(vec_a.size() == vec_result.size());//compiler may optimized auto tree vectorize (test this diabled -ftree-vectorize)for (size_t i = 0; i < vec_result.size();i++){vec_result[i] = vec_a[i] * vec_b[i];}
}
//NRON优化的vector相乘
static void neon_vector_mul(const std::vector<float>& vec_a,const std::vector<float>& vec_b,std::vector<float>& vec_result)
{assert(vec_a.size() == vec_b.size());assert(vec_a.size() == vec_result.size());int i = 0;//neon processfor (; i < (int)vec_result.size() - 3 ; i+=4){const auto data_a = vld1q_f32(&vec_a[i]);const auto data_b = vld1q_f32(&vec_b[i]);float* dst_ptr = &vec_result[i];const auto data_res = vmulq_f32(data_a, data_b);vst1q_f32(dst_ptr, data_res);}//normal processfor (; i < (int)vec_result.size(); i++){vec_result[i] = vec_a[i] * vec_b[i];}
}
//测试函数
//FuncCostTimeHelper是一个计算时间消耗的helper类
static int test_neon()
{const int test_round = 1000;const int data_len = 10000;std::vector<float> vec_a(data_len);std::vector<float> vec_b(data_len);std::vector<float> vec_result(data_len);std::vector<float> vec_result2(data_len);//fill random value in vecA & vecBfill_random_value(vec_a);fill_random_value(vec_b);//check the result is same{normal_vector_mul(vec_a, vec_b, vec_result);neon_vector_mul(vec_a, vec_b, vec_result2);if (!is_equals_vector(vec_result,vec_result2)){std::cerr << "result vector is not equals!" << std::endl;return -1;}}//test normal_vector_mul{FuncCostTimeHelper time_helper("normal_vector_mul");for (int i = 0; i < test_round;i++){normal_vector_mul(vec_a, vec_b, vec_result);}}//test neon_vector_mul{FuncCostTimeHelper time_helper("neon_vector_mul");for (int i = 0; i < test_round; i++){neon_vector_mul(vec_a, vec_b, vec_result2);}}return 0;
}int main(int, char*[])
{return test_neon();
}