bmcv_batch_topk

计算每个 db 中最大或最小的k个数，并返回index。

接口形式：

bm_status_t bmcv_batch_topk(
         bm_handle_t     handle,
         bm_device_mem_t src_data_addr,
         bm_device_mem_t src_index_addr,
         bm_device_mem_t dst_data_addr,
         bm_device_mem_t dst_index_addr,
         bm_device_mem_t buffer_addr,
         bool            src_index_valid,
         int             k,
         int             batch,
         int *           per_batch_cnt,
         bool            same_batch_cnt,
         int             src_batch_stride,
         bool            descending);

参数说明：

• bm_handle_t handle

  输入参数。 bm_handle 句柄。

• bm_device_mem_t src_data_addr

  输入参数。input_data的设备地址信息。

• bm_device_mem_t src_index_addr

  输入参数。input_index的设备地址信息，当src_index_valid为true时，设置该参数。

• bm_device_mem_t dst_data_addr

  输出参数。output_data设备地址信息。

• bm_device_mem_t dst_index_addr

  输出参数。output_index设备信息

• bm_device_mem_t buffer_addr

  输入参数。缓冲区设备地址信息

• bool src_index_valid

  输入参数。如果为true， 则使用src_index，否则使用自动生成的index。

• int k

  输入参数。k的值。

• int batch

  输入参数。batch数量。

• int * per_batch_cnt

  输入参数。每个batch的数据数量。

• bool same_batch_cnt

  输入参数。判断每个batch数据是否相同。

• int src_batch_stride

  输入参数。两个batch之间的距离。

• bool descending

  输入参数。升序或者降序

返回值说明：

• BM_SUCCESS: 成功

• 其他:失败

格式支持：

该接口目前仅支持float32类型数据。

代码示例：

int batch_num = 100000;
int k = batch_num / 10;
int descending = rand() % 2;
int batch = rand() % 20 + 1;
int batch_stride = batch_num;
bool bottom_index_valid = true;

bm_handle_t handle;
bm_status_t ret = bm_dev_request(&handle, 0);
if (ret != BM_SUCCESS) {
    std::cout << "Create bm handle failed. ret = " << ret << std::endl;
    exit(-1);
}

float* bottom_data = new float[batch * batch_stride * sizeof(float)];
int* bottom_index = new int[batch * batch_stride];
float* top_data = new float[batch * batch_stride * sizeof(float)];
int* top_index = new int[batch * batch_stride];
float* top_data_ref = new float[batch * k * sizeof(float)];
int* top_index_ref = new int[batch * k];
float* buffer = new float[3 * batch_stride * sizeof(float)];

for(int i = 0; i < batch; i++){
    for(int j = 0; j < batch_num; j++){
        bottom_data[i * batch_stride + j] = rand() % 10000 * 1.0f;
        bottom_index[i * batch_stride + j] = i * batch_stride + j;
    }
}

bm_status_t ret = bmcv_batch_topk( handle,
                                   bm_mem_from_system((void*)bottom_data),
                                   bm_mem_from_system((void*)bottom_index),
                                   bm_mem_from_system((void*)top_data),
                                   bm_mem_from_system((void*)top_index),
                                   bm_mem_from_system((void*)buffer),
                                   bottom_index_valid,
                                   k,
                                   batch,
                                   &batch_num,
                                   true,
                                   batch_stride,
                                   descending);

if(ret == BM_SUCCESS){
    int data_cmp = -1;
    int index_cmp = -1;
    data_cmp = array_cmp( (float*)top_data_ref,
                          (float*)top_data,
                          batch * k,
                          "topk data",
                          0);
    index_cmp = array_cmp( (float*)top_index_ref,
                           (float*)top_index,
                           batch * k,
                           "topk index",
                           0);
    if (data_cmp == 0 && index_cmp == 0) {
        printf("Compare success for topk data and index!\n");
    } else {
        printf("Compare failed for topk data and index!\n");
        exit(-1);
    }
} else {
    printf("Compare failed for topk data and index!\n");
    exit(-1);
}
delete [] bottom_data;
delete [] bottom_index;
delete [] top_data;
delete [] top_data_ref;
delete [] top_index;
delete [] top_index_ref;
bm_dev_free(handle);