pytorch/caffe2/operators/relu_n_op.cc
Jerry Zhang aebf3b47ae Remove template parameter from Tensor (#9939)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9939

Pull Request resolved: https://github.com/facebookresearch/weakly-supervised-action-detection/pull/13

Pull Request resolved: https://github.com/pytorch/translate/pull/166

Pull Request resolved: https://github.com/pytorch/pytorch/pull/9125

Closes https://github.com/pytorch/pytorch/pull/9125

Use inheritance for polymorphism, and remove template parameter
This is to change the templating in call sites, the core implementations will change later

Before Caffe2 Tensor class was compile-time fixed to bind to a particular device/context. With this change, we're making it a runtime property (stored inside the tensor), but preserve the same semantics. For example, one has to specify device type in order to create a Tensor - there are no uninitialized tensors. More specifically the changes are:

1. We added an extra argument *DeviceType* to most of the constructors of the tensor, e.g. (Tensor(DeviceType type)),
2. Semantics of constructor Tensor(const Tensor<SrcContext>& src, ContextForCopy* context); is changed, in this constructor, the second context is passed in to enable us to call the templated Copy function, it could be in a different context as source and target previously, now we'll enforce that the context should have same device type as src, if it is provided.
3. To preserve 'get-or-construct' semantics of Blob, we added specialized getter Blob::GetMutableTensor that verifies both that Blob contains a Tensor and that it's of a correct type
4. Specifically, Tensor type is not default-constructible any more (as we don't have unknown device tensors) and thus some of the code handling STL containers needs to change

Note: Some changes are postponed just to keep this diff a bit smaller. Please see `TODO`s.

Reviewed By: ezyang, houseroad

Differential Revision: D9024330

fbshipit-source-id: e0b8295d2dc6ebe2963383ded5af799ad17164ba
2018-07-27 10:56:39 -07:00

108 lines
2.7 KiB
C++

#include "caffe2/operators/relu_n_op.h"
#include <algorithm>
#include <functional>
#include <string>
#include "caffe2/utils/eigen_utils.h"
namespace caffe2 {
template <>
template <typename T>
bool ReluNFunctor<CPUContext>::
operator()(const int N, const T* X, T* Y, CPUContext* /* context */) const {
EigenVectorMap<T>(Y, N) =
ConstEigenVectorMap<T>(X, N).cwiseMax(T(0)).cwiseMin(T(n));
return true;
}
template <>
template <typename T>
bool ReluNGradientFunctor<CPUContext>::Forward(
const std::vector<int>& Y_dims,
const std::vector<int>& /* dY_dims */,
const T* Y,
const T* dY,
T* dX,
CPUContext* /* context */) const {
const int size = std::accumulate(
Y_dims.cbegin(), Y_dims.cend(), 1, std::multiplies<int>());
ConstEigenVectorArrayMap<T> Y_arr(Y, size);
EigenVectorArrayMap<T>(dX, size) =
(Y_arr > T(0) && Y_arr < T(n))
.select(ConstEigenVectorArrayMap<T>(dY, size), T(0));
return true;
}
namespace {
OpSchema::Cost CostInferenceForReluN(
const OperatorDef& def,
const vector<TensorShape>& in) {
struct OpSchema::Cost cost = PointwiseCostInference<2>(def, in);
cost.params_bytes = 0;
return cost;
}
} // namespace
REGISTER_CPU_OPERATOR(
ReluN,
UnaryElementwiseWithArgsOp<
TensorTypes<float>,
CPUContext,
ReluNFunctor<CPUContext>>);
REGISTER_CPU_OPERATOR(
ReluNGradient,
BinaryElementwiseWithArgsOp<
TensorTypes<float>,
CPUContext,
ReluNGradientFunctor<CPUContext>>);
// Input: X, output: Y
OPERATOR_SCHEMA(ReluN)
.NumInputs(1)
.NumOutputs(1)
.Arg("n", "the cap of output")
.AllowInplace({{0, 0}})
.CostInferenceFunction(CostInferenceForReluN)
.IdenticalTypeAndShape()
.SetDoc(R"DOC(
Relu takes one input data (Tensor) and produces one output data
(Tensor) where the rectified linear function, y = min(max(0, x), n),
is applied to the tensor elementwise.
)DOC")
.Input(0, "X", "1D input tensor")
.Output(0, "Y", "1D input tensor");
// Input: Y, dY, output: dX
OPERATOR_SCHEMA(ReluNGradient)
.NumInputs(2)
.NumOutputs(1)
.Arg("n", "the cap of forward op output")
.AllowInplace({{1, 0}})
.SetDoc(R"DOC(
ReluGradient takes both Y and dY and uses this to update dX according to the
chain rule and derivatives of the rectified linear function.
)DOC");
namespace {
class GetReluNGradient : public GradientMakerBase {
using GradientMakerBase::GradientMakerBase;
std::vector<OperatorDef> GetGradientDefs() override {
return SingleGradientDef(
def_.type() + "Gradient",
"",
std::vector<std::string>{O(0), GO(0)},
std::vector<std::string>{GI(0)});
}
};
} // namespace
REGISTER_GRADIENT(ReluN, GetReluNGradient);
} // namespace caffe2