refine cross_entropy mem

test=develop

paddle/fluid/operators/cross_entropy2_op.cc

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/operators/cross_entropy2_op.h"
+#include <memory>
+#include <string>
+#include <unordered_map>
+
+namespace paddle {
+namespace operators {
+
+class CrossEntropyOp2 : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("X"), "Input(X) should be not null.");
+    PADDLE_ENFORCE(ctx->HasInput("Label"), "Input(Label) should be not null.");
+
+    PADDLE_ENFORCE(ctx->HasOutput("Y"), "Output(Y) should be not null.");
+    PADDLE_ENFORCE(ctx->HasOutput("XShape"),
+                   "Output(XShape) should be not null.");
+
+    auto x_dims = ctx->GetInputDim("X");
+    auto label_dims = ctx->GetInputDim("Label");
+    int rank = x_dims.size();
+    PADDLE_ENFORCE_EQ(rank, label_dims.size(),
+                      "Input(X) and Input(Label) shall have the same rank.");
+    bool check = true;
+    if ((!ctx->IsRuntime()) && (framework::product(x_dims) <= 0 ||
+                                framework::product(label_dims) <= 0)) {
+      check = false;
+    }
+    if (check) {
+      PADDLE_ENFORCE_EQ(framework::slice_ddim(x_dims, 0, rank - 1),
+                        framework::slice_ddim(label_dims, 0, rank - 1),
+                        "Input(X) and Input(Label) shall have the same shape "
+                        "except the last dimension.");
+    }
+
+    PADDLE_ENFORCE_EQ(label_dims[rank - 1], 1UL,
+                      "Last dimension of Input(Label) should be 1.");
+    auto y_dims = x_dims;
+    y_dims[rank - 1] = 1;
+    ctx->SetOutputDim("Y", y_dims);
+    ctx->ShareLoD("X", /*->*/ "Y");
+
+    auto x_dims_vec = framework::vectorize(x_dims);
+    x_dims_vec.push_back(0);
+    ctx->SetOutputDim("XShape", framework::make_ddim(x_dims_vec));
+    ctx->ShareLoD("X", /*->*/ "XShape");
+  }
+
+ protected:
+  // Explicitly set that the data type of computation kernel of cross_entropy
+  // is determined by its input "X".
+  framework::OpKernelType GetExpectedKernelType(
+      const framework::ExecutionContext& ctx) const override {
+    return framework::OpKernelType(ctx.Input<Tensor>("X")->type(),
+                                   ctx.device_context());
+  }
+};
+
+class CrossEntropyGradientOp2 : public framework::OperatorWithKernel {
+ public:
+  using framework::OperatorWithKernel::OperatorWithKernel;
+
+  void InferShape(framework::InferShapeContext* ctx) const override {
+    PADDLE_ENFORCE(ctx->HasInput("Label"), "Input(Label) should be not null.");
+    PADDLE_ENFORCE(ctx->HasInput("XShape"),
+                   "Input(XShape) should be not null.");
+    PADDLE_ENFORCE(ctx->HasInput("Y"), "Input(Y) should be not null.");
+
+    PADDLE_ENFORCE(ctx->HasInput(framework::GradVarName("Y")),
+                   "Input(Y@GRAD) shoudl be not null.");
+
+    PADDLE_ENFORCE(ctx->HasOutput(framework::GradVarName("X")),
+                   "Output(X@GRAD) should be not null.");
+
+    auto x_shapes = ctx->GetInputDim("XShape");
+    framework::DDim x_dims(x_shapes.Get(), x_shapes.size() - 1);
+    auto label_dims = ctx->GetInputDim("Label");
+    auto dy_dims = ctx->GetInputDim(framework::GradVarName("Y"));
+    int rank = x_dims.size();
+    PADDLE_ENFORCE_EQ(dy_dims.size(), rank,
+                      "Input(Y@Grad) and Input(X) should have the same rank.");
+    PADDLE_ENFORCE_EQ(label_dims.size(), rank,
+                      "Input(Label) and Input(X) should have the same rank.");
+
+    bool check = true;
+    if ((!ctx->IsRuntime()) && (framework::product(x_dims) <= 0 ||
+                                framework::product(label_dims) <= 0)) {
+      check = false;
+    }
+
+    if (check) {
+      PADDLE_ENFORCE_EQ(framework::slice_ddim(x_dims, 0, rank - 1),
+                        framework::slice_ddim(label_dims, 0, rank - 1),
+                        "The Input(X) and Input(Label) should have the same "
+                        "shape except the last dimension.");
+      PADDLE_ENFORCE_EQ(framework::slice_ddim(x_dims, 0, rank - 1),
+                        framework::slice_ddim(dy_dims, 0, rank - 1),
+                        "The Input(X) and Input(Y@Grad) should have the same "
+                        "shape except the last dimension.");
+    }
+    PADDLE_ENFORCE_EQ(dy_dims[rank - 1], 1,
+                      "The last dimension of Input(Y@Grad) should be 1.");
+    PADDLE_ENFORCE_EQ(label_dims[rank - 1], 1,
+                      "Last dimension of Input(Label) should be 1.");
+    ctx->SetOutputDim(framework::GradVarName("X"), x_dims);
+    ctx->ShareLoD("XShape", framework::GradVarName("X"));
+  }
+
+ protected:
+  // Explicitly set that the data type of computation kernel of cross_entropy
+  // is determined by its input "X".
+  framework::OpKernelType GetExpectedKernelType(
+      const framework::ExecutionContext& ctx) const override {
+    return framework::OpKernelType(
+        ctx.Input<Tensor>(framework::GradVarName("Y"))->type(),
+        ctx.device_context());
+  }
+};
+
+class CrossEntropyOpMaker2 : public framework::OpProtoAndCheckerMaker {
+ public:
+  void Make() override {
+    AddInput("X",
+             "(Tensor, default Tensor<float>), a tensor whose last dimension "
+             "size is equal to the number of classes. This input is a "
+             "probability computed by the previous operator, which is almost "
+             "always the result of a softmax operator.");
+    AddInput(
+        "Label",
+        "(Tensor), the tensor which represents the ground truth. It has the "
+        "same shape with 'X' except the last dimension. One hot Tensor.");
+    AddOutput("Y",
+              "(Tensor, default Tensor<float>), a tensor whose shape is same "
+              "with 'X' except that the last dimension size is 1. It "
+              "represents the cross entropy loss.");
+    AddOutput("XShape", "Temporaily variable to save shape and LoD of X.");
+    AddAttr<int>("ignore_index",
+                 "(int, default -100), Specifies a target value that is"
+                 "ignored and does not contribute to the input gradient."
+                 "Only valid if soft_label is set to False")
+        .SetDefault(-100);
+    AddComment(R"DOC(
+CrossEntropy Operator.
+
+The input 'X' and 'Label' will first be logically flattened to 2-D matrixs. 
+The matrix's second dimension(row length) is as same as the original last 
+dimension, and the first dimension(column length) is the product of all other 
+original dimensions. Then the softmax computation will take palce on each raw 
+of flattened matrixs.
+
+Only support hard label.
+
+Both the input X and Label can carry the LoD (Level of Details) information,
+or not. But the output only shares the LoD information with input X.
+
+)DOC");
+  }
+};
+
+class CrossEntropyOpInferVarType2
+    : public framework::PassInDtypeAndVarTypeToOutput {
+ protected:
+  std::unordered_map<std::string, std::string> GetInputOutputWithSameType()
+      const override {
+    return std::unordered_map<std::string, std::string>{{"X", /*->*/ "Y"}};
+  }
+};
+
+class CrossEntropyGradOpMaker2 : public framework::SingleGradOpDescMaker {
+ public:
+  using framework::SingleGradOpDescMaker::SingleGradOpDescMaker;
+
+ protected:
+  std::unique_ptr<framework::OpDesc> Apply() const override {
+    std::unique_ptr<framework::OpDesc> op(new framework::OpDesc());
+    op->SetType("cross_entropy_grad2");
+    op->SetInput("Label", Input("Label"));
+    op->SetInput("Y", Output("Y"));
+    op->SetInput("XShape", Output("XShape"));
+    op->SetInput(framework::GradVarName("Y"), OutputGrad("Y"));
+    op->SetOutput(framework::GradVarName("X"), InputGrad("X"));
+    op->SetAttrMap(Attrs());
+    return op;
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle
+
+namespace ops = paddle::operators;
+using CPUCtx = paddle::platform::CPUDeviceContext;
+
+REGISTER_OPERATOR(cross_entropy2, ops::CrossEntropyOp2,
+                  ops::CrossEntropyOpMaker2, ops::CrossEntropyOpInferVarType2,
+                  ops::CrossEntropyGradOpMaker2);
+REGISTER_OPERATOR(cross_entropy_grad2, ops::CrossEntropyGradientOp2);
+REGISTER_OP_CPU_KERNEL(cross_entropy2,
+                       ops::CrossEntropyOpKernel2<CPUCtx, float>,
+                       ops::CrossEntropyOpKernel2<CPUCtx, double>);
+REGISTER_OP_CPU_KERNEL(cross_entropy_grad2,
+                       ops::CrossEntropyGradientOpKernel2<CPUCtx, float>,
+                       ops::CrossEntropyGradientOpKernel2<CPUCtx, double>);

paddle/fluid/operators/cross_entropy2_op.cu

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#include "paddle/fluid/operators/cross_entropy2_op.h"
+#include "paddle/fluid/platform/float16.h"
+
+namespace plat = paddle::platform;
+namespace ops = paddle::operators;
+using CUDACtx = paddle::platform::CUDADeviceContext;
+REGISTER_OP_CUDA_KERNEL(cross_entropy2,
+                        ops::CrossEntropyOpKernel2<CUDACtx, float>,
+                        ops::CrossEntropyOpKernel2<CUDACtx, double>,
+                        ops::CrossEntropyOpKernel2<CUDACtx, plat::float16>);
+
+REGISTER_OP_CUDA_KERNEL(
+    cross_entropy_grad2, ops::CrossEntropyGradientOpKernel2<CUDACtx, float>,
+    ops::CrossEntropyGradientOpKernel2<CUDACtx, double>,
+    ops::CrossEntropyGradientOpKernel2<CUDACtx, plat::float16>);

paddle/fluid/operators/cross_entropy2_op.h

+/* Copyright (c) 2016 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#pragma once
+
+#include <cmath>
+#include "paddle/fluid/framework/eigen.h"
+#include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/math/cross_entropy.h"
+#include "paddle/fluid/operators/math/math_function.h"
+#include "paddle/fluid/platform/for_range.h"
+
+namespace paddle {
+namespace operators {
+
+using Tensor = framework::Tensor;
+
+HOSTDEVICE inline platform::float16 RealLog(platform::float16 x) {
+#ifdef __NVCC__
+  return static_cast<platform::float16>(logf(static_cast<float>(x)));
+#else
+  return static_cast<platform::float16>(std::log(static_cast<float>(x)));
+#endif
+}
+
+HOSTDEVICE inline float RealLog(float x) {
+#ifdef __NVCC__
+  return logf(x);
+#else
+  return std::log(x);
+#endif
+}
+
+HOSTDEVICE inline double RealLog(double x) {
+#ifdef __NVCC__
+  return log(x);
+#else
+  return std::log(x);
+#endif
+}
+
+HOSTDEVICE inline platform::float16 RealExp(platform::float16 x) {
+#ifdef __NVCC__
+  return static_cast<platform::float16>(expf(static_cast<float>(x)));
+#else
+  return static_cast<platform::float16>(std::exp(static_cast<float>(x)));
+#endif
+}
+
+HOSTDEVICE inline float RealExp(float x) {
+#ifdef __NVCC__
+  return expf(x);
+#else
+  return std::exp(x);
+#endif
+}
+
+HOSTDEVICE inline double RealExp(double x) {
+#ifdef __NVCC__
+  return exp(x);
+#else
+  return std::exp(x);
+#endif
+}
+
+template <typename T>
+struct CrossEntropyForwardFunctor {
+  CrossEntropyForwardFunctor(const T *x, T *y, const int64_t *label,
+                             int64_t ignore_index, int64_t feature_size)
+      : x_(x),
+        y_(y),
+        label_(label),
+        ignore_index_(ignore_index),
+        feature_size_(feature_size) {}
+
+  HOSTDEVICE void operator()(int64_t row_idx) const {
+    auto col_idx = label_[row_idx];
+    if (col_idx != ignore_index_) {
+      y_[row_idx] = -math::TolerableValue<T>()(
+          RealLog(x_[row_idx * feature_size_ + col_idx]));
+    } else {
+      y_[row_idx] = 0;
+    }
+  }
+
+  const T *x_;
+  T *y_;
+  const int64_t *label_;
+  int64_t ignore_index_;
+  int64_t feature_size_;
+};
+
+template <typename T>
+struct CrossEntropyBackwardFunctor {
+  CrossEntropyBackwardFunctor(T *dx, const T *y, const T *dy,
+                              const int64_t *label, int64_t ignore_index,
+                              int64_t feature_size)
+      : dx_(dx),
+        y_(y),
+        dy_(dy),
+        label_(label),
+        ignore_index_(ignore_index),
+        feature_size_(feature_size) {}
+
+  HOSTDEVICE void operator()(int64_t idx) const {
+    auto row_idx = idx / feature_size_;
+    auto col_idx = idx % feature_size_;
+    auto label = label_[row_idx];
+    if (label == col_idx && label != ignore_index_) {
+      dx_[idx] = -dy_[row_idx] * RealExp(y_[row_idx]);
+    } else {
+      dx_[idx] = 0;
+    }
+  }
+
+  T *dx_;
+  const T *y_;
+  const T *dy_;
+  const int64_t *label_;
+  int64_t ignore_index_;
+  int64_t feature_size_;
+};
+
+template <typename DeviceContext, typename T>
+class CrossEntropyOpKernel2 : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext &ctx) const override {
+    auto *x = ctx.Input<Tensor>("X");
+    auto *label = ctx.Input<Tensor>("Label");
+    auto *y = ctx.Output<Tensor>("Y");
+
+    auto *p_y = y->mutable_data<T>(ctx.GetPlace());
+    auto *p_x = x->data<T>();
+    auto *p_label = label->data<int64_t>();
+
+    int rank = x->dims().size();
+    int64_t feature_size = x->dims()[rank - 1];
+    int64_t batch_size = framework::product(x->dims()) / feature_size;
+
+    int64_t ignore_index = ctx.Attr<int>("ignore_index");
+
+    platform::ForRange<DeviceContext> for_range(
+        ctx.template device_context<DeviceContext>(), batch_size);
+    for_range(CrossEntropyForwardFunctor<T>(p_x, p_y, p_label, ignore_index,
+                                            feature_size));
+  }
+};
+
+template <typename DeviceContext, typename T>
+class CrossEntropyGradientOpKernel2 : public framework::OpKernel<T> {
+ public:
+  void Compute(const framework::ExecutionContext &ctx) const override {
+    auto *dx = ctx.Output<Tensor>(framework::GradVarName("X"));
+    auto *y = ctx.Input<Tensor>("Y");
+    auto *dy = ctx.Input<Tensor>(framework::GradVarName("Y"));
+    auto *label = ctx.Input<Tensor>("Label");
+
+    auto *p_dx = dx->mutable_data<T>(ctx.GetPlace());
+    auto *p_y = y->data<T>();
+    auto *p_dy = dy->data<T>();
+    auto *p_label = label->data<int64_t>();
+
+    int64_t ignore_index = ctx.Attr<int>("ignore_index");
+    int rank = dx->dims().size();
+    int64_t feature_size = dx->dims()[rank - 1];
+    int64_t batch_size = framework::product(dx->dims()) / feature_size;
+
+    platform::ForRange<DeviceContext> for_range(
+        ctx.template device_context<DeviceContext>(),
+        batch_size * feature_size);
+    for_range(CrossEntropyBackwardFunctor<T>(p_dx, p_y, p_dy, p_label,
+                                             ignore_index, feature_size));
+  }
+};
+
+}  // namespace operators
+}  // namespace paddle

python/paddle/fluid/layers/nn.py

@@ -1432,6 +1432,8 @@ def cross_entropy(input, label, soft_label=False, ignore_index=kIgnoreIndex):
           predict = fluid.layers.fc(input=net, size=classdim, act='softmax')
           cost = fluid.layers.cross_entropy(input=predict, label=label)
     """
+    if not soft_label:
+        return cross_entropy2(input, label, ignore_index)
     helper = LayerHelper('cross_entropy', **locals())
     out = helper.create_variable_for_type_inference(dtype=input.dtype)
     helper.append_op(
@@ -1444,6 +1446,20 @@ def cross_entropy(input, label, soft_label=False, ignore_index=kIgnoreIndex):
     return out
 
 
+def cross_entropy2(input, label, ignore_index=kIgnoreIndex):
+    helper = LayerHelper('cross_entropy2', **locals())
+    out = helper.create_variable_for_type_inference(dtype=input.dtype)
+    xshape = helper.create_variable_for_type_inference(dtype=input.dtype)
+    helper.append_op(
+        type='cross_entropy2',
+        inputs={'X': [input],
+                'Label': [label]},
+        outputs={'Y': [out],
+                 'XShape': [xshape]},
+        attrs={'ignore_index': ignore_index})
+    return out
+
+
 def bpr_loss(input, label, name=None):
     """
     Bayesian Personalized Ranking Loss Operator.