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aclnnNLLLoss

接口原型

每个算子有两段接口,必须先调用“aclnnXxxGetWorkspaceSize”接口获取入参并根据计算流程计算所需workspace大小,再调用“aclnnXxx”接口执行计算。两段式接口如下:

  • 第一段接口:aclnnStatus aclnnNLLLossGetWorkspaceSize(const aclTensor *self, const aclTensor *target, const aclTensor *weight, int64_t reduction, int64_t ignoreIndex, aclTensor *out, aclTensor *totalWeightOut, uint64_t *workspaceSize, aclOpExecutor **executor)
  • 第二段接口:aclnnStatus aclnnNLLLoss(void *workspace, uint64_t workspaceSize, aclOpExecutor *executor, aclrtStream stream)

功能描述

  • 算子功能:计算负对数似然损失值。
  • 计算公式:
    • 当reduction为none时,公式如下,

    • 当reduction不为none时,公式如下:

    其中输入张量为x,真实标签为y,每个类别的缩放权重为w,N是batch size。

aclnnNLLLossGetWorkspaceSize

  • 接口定义:

    aclnnStatus aclnnNLLLossGetWorkspaceSize(const aclTensor *self, const aclTensor *target, const aclTensor *weight, int64_t reduction, int64_t ignoreIndex, aclTensor *out, aclTensor *totalWeightOut, uint64_t *workspaceSize, aclOpExecutor **executor)

  • 参数说明:
    • self(aclTensor*, 计算输入): 公式中的输入self,shape为(N,C)或者(C),其中N表示batch size,C表示类别数。数据类型支持FLOAT、FLOAT16、BFLOAT16(仅Atlas A2训练系列产品支持),支持非连续的Tensor, 数据格式支持ND。
    • target(aclTensor*, 计算输入): 公式中的输入target,表示真实标签,shape为(N) 或者(),其中每个元素的取值范围是[0, C-1]。数据类型支持INT64、UINT8、INT32 ,支持非连续的Tensor, 数据格式支持ND。
    • weight(aclTensor*, 计算输入): 公式中的输入weight,表示每个类别的缩放权重,shape为(C)。数据类型支持FLOAT、FLOAT16、BFLOAT16(仅Atlas A2训练系列产品支持),支持非连续的Tensor,数据格式支持ND。
    • reduction(int64_t, 计算输入): 公式中的reduction,指定要应用到输出的缩减。支持3种枚举值:当取值为0,即为"none",表示不应用减少;当取值为1,即为"mean",表示输出的总和将除以输出中的元素数;当取值为2,即为"sum", 表示输出将被求和。
    • ignoreIndex(int64_t, 计算输入): 公式中的ignoreIndex,指定一个被忽略且不影响输入梯度的目标值。
    • out(aclTensor*, 计算输出): 公式中的out,shape为(N, )或者(),数据格式支持ND。
    • totalWeightOut(aclTensor*, 计算输出): 公式中的totalWeightOut,shape为()。数据格式支持ND。
    • workspaceSize(uint64_t*, 出参):返回用户需要在Device侧申请的workspace大小
    • executor(aclOpExecutor**, 出参):返回op执行器,包含了算子计算流程。
  • 返回值:

    返回aclnnStatus状态码,具体参见aclnn返回码

    第一段接口完成入参校验,出现以下场景时报错:

    • 返回161001(ACLNN_ERR_PARAM_NULLPTR):传入的self、target、weight、out、totalWeightOut为空指针。
    • 返回161002(ACLNN_ERR_PARAM_INVALID):
      • self、target、weight的数据类型不在支持的范围内。
      • self、weight的数据类型不一致。
      • self、weight、out、totalWeightOut的shape不正确。
      • reduction值不在0~2范围之内。

aclnnNLLLoss

  • 接口定义:

    aclnnStatus aclnnNLLLoss(void *workspace, uint64_t workspaceSize, aclOpExecutor *executor, aclrtStream stream)

  • 参数说明:
    • workspace:在Device侧申请的workspace内存起址。
    • workspaceSize:在Device侧申请的workspace大小,由第一段接口aclnnNLLLossGetWorkspaceSize获取。
    • executor:op执行器,包含了算子计算流程。
    • stream:指定执行任务的AscendCL stream流。
  • 返回值:

    返回aclnnStatus状态码,具体参见aclnn返回码

调用示例

#include <iostream>
#include <vector>
#include "acl/acl.h"
#include "aclnnop/aclnn_nll_loss.h"

#define CHECK_RET(cond, return_expr) \
  do {                               \
    if (!(cond)) {                   \
      return_expr;                   \
    }                                \
  } while (0)

#define LOG_PRINT(message, ...)     \
  do {                              \
    printf(message, ##__VA_ARGS__); \
  } while (0)

int64_t GetShapeSize(const std::vector<int64_t>& shape) {
  int64_t shape_size = 1;
  for (auto i : shape) {
    shape_size *= i;
  }
  return shape_size;
}

int Init(int32_t deviceId, aclrtContext* context, aclrtStream* stream) {
  // 固定写法,AscendCL初始化
  auto ret = aclInit(nullptr);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclInit failed. ERROR: %d\n", ret); return ret);
  ret = aclrtSetDevice(deviceId);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclrtSetDevice failed. ERROR: %d\n", ret); return ret);
  ret = aclrtCreateContext(context, deviceId);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclrtCreateContext failed. ERROR: %d\n", ret); return ret);
  ret = aclrtSetCurrentContext(*context);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclrtSetCurrentContext failed. ERROR: %d\n", ret); return ret);
  ret = aclrtCreateStream(stream);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclrtCreateStream failed. ERROR: %d\n", ret); return ret);
  return 0;
}

template <typename T>
int CreateAclTensor(const std::vector<T>& hostData, const std::vector<int64_t>& shape, void** deviceAddr,
                    aclDataType dataType, aclTensor** tensor) {
  auto size = GetShapeSize(shape) * sizeof(T);
  // 调用aclrtMalloc申请device侧内存
  auto ret = aclrtMalloc(deviceAddr, size, ACL_MEM_MALLOC_HUGE_FIRST);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclrtMalloc failed. ERROR: %d\n", ret); return ret);

  // 调用aclrtMemcpy将Host侧数据拷贝到device侧内存上
  ret = aclrtMemcpy(*deviceAddr, size, hostData.data(), size, ACL_MEMCPY_HOST_TO_DEVICE);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclrtMemcpy failed. ERROR: %d\n", ret); return ret);

  // 计算连续tensor的strides
  std::vector<int64_t> strides(shape.size(), 1);
  for (int64_t i = shape.size() - 2; i >= 0; i--) {
    strides[i] = shape[i + 1] * strides[i + 1];
  }

  // 调用aclCreateTensor接口创建aclTensor
  *tensor = aclCreateTensor(shape.data(), shape.size(), dataType, strides.data(), 0, aclFormat::ACL_FORMAT_ND,
                            shape.data(), shape.size(), *deviceAddr);
  return 0;
}

int main() {
  // 1. device/context/stream初始化, 参考AscendCL对外接口列表
  // 根据自己的实际device填写deviceId
  int32_t deviceId = 0;
  aclrtContext context;
  aclrtStream stream;
  auto ret = Init(deviceId, &context, &stream);
  // check根据自己的需要处理
  CHECK_RET(ret == 0, LOG_PRINT("Init acl failed. ERROR: %d\n", ret); return ret);

  // 2. 构造输入与输出,需要根据API的接口自定义构造
  std::vector<int64_t> selfShape = {2, 3};
  std::vector<int64_t> targetShape = {2};
  std::vector<int64_t> weightShape = {3};
  std::vector<int64_t> outShape = {2};
  std::vector<int64_t> totalWeightOutShape = {1};

  void* selfDeviceAddr = nullptr;
  void* targetDeviceAddr = nullptr;
  void* weightDeviceAddr = nullptr;
  void* outDeviceAddr = nullptr;
  void* totalWeightOutDeviceAddr = nullptr;
  aclTensor* self = nullptr;
  aclTensor* target = nullptr;
  aclTensor* weight = nullptr;
  aclTensor* out = nullptr;
  aclTensor* totalWeightOut = nullptr;

  std::vector<float> selfHostData = {0, 1, 2, 3, 4, 5};
  std::vector<int32_t> targetHostData = {0, 2};
  std::vector<float> weightHostData = {1.1, 1.2, 1.3};
  std::vector<float> outHostData = {0, 0};
  std::vector<float> totalWeightOutHostData = {0};
  int64_t reduction = 0;
  int64_t ignoreIndex = -100;

  // 创建self aclTensor
  ret = CreateAclTensor(selfHostData, selfShape, &selfDeviceAddr, aclDataType::ACL_FLOAT, &self);
  CHECK_RET(ret == ACL_SUCCESS, return ret);
  // 创建target aclTensor
  ret = CreateAclTensor(targetHostData, targetShape, &targetDeviceAddr, aclDataType::ACL_INT32, &target);
  CHECK_RET(ret == ACL_SUCCESS, return ret);
  // 创建weight aclScalar
  ret = CreateAclTensor(weightHostData, weightShape, &weightDeviceAddr, aclDataType::ACL_FLOAT, &weight);
  CHECK_RET(ret == ACL_SUCCESS, return ret);
  // 创建out aclTensor
  ret = CreateAclTensor(outHostData, outShape, &outDeviceAddr, aclDataType::ACL_FLOAT, &out);
  CHECK_RET(ret == ACL_SUCCESS, return ret);
  // 创建totalWeightOut aclTensor
  ret = CreateAclTensor(totalWeightOutHostData, totalWeightOutShape, &totalWeightOutDeviceAddr, aclDataType::ACL_FLOAT,
                        &totalWeightOut);
  CHECK_RET(ret == ACL_SUCCESS, return ret);

  // 3. 调用CANN算子库API
  uint64_t workspaceSize = 0;
  aclOpExecutor* executor;
  // 调用aclnnNLLLoss第一段接口
  ret = aclnnNLLLossGetWorkspaceSize(self, target, weight, reduction, ignoreIndex, out, totalWeightOut, &workspaceSize,&executor);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclnnNLLLossGetWorkspaceSize failed. ERROR: %d\n", ret); return ret);
  // 根据第一段接口计算出的workspaceSize申请device内存
  void* workspaceAddr = nullptr;
  if (workspaceSize > 0) {
    ret = aclrtMalloc(&workspaceAddr, workspaceSize, ACL_MEM_MALLOC_HUGE_FIRST);
    CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("allocate workspace failed. ERROR: %d\n", ret); return ret;);
  }
  // 调用aclnnNLLLoss第二段接口
  ret = aclnnNLLLoss(workspaceAddr, workspaceSize, executor, stream);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclnnNLLLoss failed. ERROR: %d\n", ret); return ret);

  // 4.(固定写法)同步等待任务执行结束
  ret = aclrtSynchronizeStream(stream);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("aclrtSynchronizeStream failed. ERROR: %d\n", ret); return ret);

  // 5.. 获取输出的值,将device侧内存上的结果拷贝至Host侧
  auto size = GetShapeSize(outShape);
  std::vector<float> resultData(size, 0);
  ret = aclrtMemcpy(resultData.data(), resultData.size() * sizeof(resultData[0]), outDeviceAddr, size * sizeof(float),ACL_MEMCPY_DEVICE_TO_HOST);
  CHECK_RET(ret == ACL_SUCCESS, LOG_PRINT("copy result from device to host failed. ERROR: %d\n", ret); return ret);
  for (int64_t i = 0; i < size; i++) {
    LOG_PRINT("result[%ld] is: %f\n", i, resultData[i]);
  }

  // 6.释放aclTensor和aclScalar
  aclDestroyTensor(self);
  aclDestroyTensor(target);
  aclDestroyTensor(weight);
  aclDestroyTensor(out);
  return 0;
}