smooth_l1_loss_op.h

#ifndef SMOOTH_L1_LOSS_OP_H_
#define SMOOTH_L1_LOSS_OP_H_

#include "caffe2/core/context.h"
#include "caffe2/core/logging.h"
#include "caffe2/core/operator.h"
#include "caffe2/utils/math.h"

namespace caffe2 {

template <typename T, class Context>
class SmoothL1LossOp final : public Operator<Context> {
 public:
  SmoothL1LossOp(const OperatorDef& operator_def, Workspace* ws)
      : Operator<Context>(operator_def, ws),
        beta_(this->template GetSingleArgument<float>("beta", 1.)),
        scale_(this->template GetSingleArgument<float>("scale", 1.)) {
    CAFFE_ENFORCE(beta_ > 0);
    CAFFE_ENFORCE(scale_ >= 0);
  }
  USE_OPERATOR_CONTEXT_FUNCTIONS;

  bool RunOnDevice() override {
    // No CPU implementation for now
    CAFFE_NOT_IMPLEMENTED;
  }

 protected:
  float beta_; // Transition point from L1 to L2 loss
  float scale_; // Scale the loss by scale_
  Tensor buff_{Context::GetDeviceType()}; // Buffer for element-wise differences
};

template <typename T, class Context>
class SmoothL1LossGradientOp final : public Operator<Context> {
 public:
  SmoothL1LossGradientOp(const OperatorDef& def, Workspace* ws)
      : Operator<Context>(def, ws),
        beta_(this->template GetSingleArgument<float>("beta", 1.)),
        scale_(this->template GetSingleArgument<float>("scale", 1.)) {
    CAFFE_ENFORCE(beta_ > 0);
    CAFFE_ENFORCE(scale_ >= 0);
  }
  USE_OPERATOR_CONTEXT_FUNCTIONS;

  bool RunOnDevice() override {
    // No CPU implementation for now
    CAFFE_NOT_IMPLEMENTED;
  }

 protected:
  float beta_; // Transition point from L1 to L2 loss
  float scale_; // Scale the loss by scale_
  Tensor buff_{Context::GetDeviceType()}; // Buffer for element-wise differences
};

} // namespace caffe2

#endif // SMOOTH_L1_LOSS_OP_H_