Merge pull request #14511 from jerrywgz/ignore_index_for_sigmoid_cross_entropy

add ignore index for sigmoid cross entropy with logits op, test=develop

paddle/fluid/API.spec

@@ -182,7 +182,7 @@ paddle.fluid.layers.clip ArgSpec(args=['x', 'min', 'max', 'name'], varargs=None,
 paddle.fluid.layers.clip_by_norm ArgSpec(args=['x', 'max_norm', 'name'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.layers.mean ArgSpec(args=['x', 'name'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.layers.mul ArgSpec(args=['x', 'y', 'x_num_col_dims', 'y_num_col_dims', 'name'], varargs=None, keywords=None, defaults=(1, 1, None))
-paddle.fluid.layers.sigmoid_cross_entropy_with_logits ArgSpec(args=['x', 'label', 'name'], varargs=None, keywords=None, defaults=(None,))
+paddle.fluid.layers.sigmoid_cross_entropy_with_logits ArgSpec(args=['x', 'label', 'ignore_index', 'name'], varargs=None, keywords=None, defaults=(-100, None))
 paddle.fluid.layers.maxout ArgSpec(args=['x', 'groups', 'name'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.layers.space_to_depth ArgSpec(args=['x', 'blocksize', 'name'], varargs=None, keywords=None, defaults=(None,))
 paddle.fluid.layers.affine_grid ArgSpec(args=['theta', 'out_shape', 'name'], varargs=None, keywords=None, defaults=(None,))

paddle/fluid/operators/sigmoid_cross_entropy_with_logits_op.cc

@@ -18,6 +18,7 @@ namespace paddle {
 namespace operators {
 
 using framework::Tensor;
+const int kIgnoreIndex = -100;
 
 class SigmoidCrossEntropyWithLogitsOp : public framework::OperatorWithKernel {
  public:
@@ -100,6 +101,11 @@ class SigmoidCrossEntropyWithLogitsOpMaker
     AddOutput("Out",
               "(Tensor, default Tensor<float>), a 2-D tensor with shape N x D "
               " of elementwise logistic losses.");
+    AddAttr<int>("ignore_index",
+                 "(int, default kIgnoreIndex), Specifies a target value that "
+                 "is ignored and"
+                 "does not contribute to the input gradient.")
+        .SetDefault(kIgnoreIndex);
     AddComment(R"DOC(
 SigmoidCrossEntropyWithLogits Operator.
 

paddle/fluid/operators/sigmoid_cross_entropy_with_logits_op.h

@@ -15,33 +15,72 @@ limitations under the License. */
 #pragma once
 #include "paddle/fluid/framework/eigen.h"
 #include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/platform/hostdevice.h"
+#include "paddle/legacy/utils/Logging.h"
 
 namespace paddle {
 namespace operators {
 
+using Tensor = framework::Tensor;
+template <typename T, int MajorType = Eigen::RowMajor,
+          typename IndexType = Eigen::DenseIndex>
+using EigenVector = framework::EigenVector<T, MajorType, IndexType>;
+template <typename T, int MajorType = Eigen::RowMajor,
+          typename IndexType = Eigen::DenseIndex>
+using EigenMatrix = framework::EigenMatrix<T, MajorType, IndexType>;
+
+template <typename T>
+struct SigmoidCrossEntropyWithLogitsForward {
+  HOSTDEVICE SigmoidCrossEntropyWithLogitsForward(const int &ignore_index)
+      : ignore_index(ignore_index) {}
+
+  HOSTDEVICE T operator()(const T &x, const T &label) const {
+    if (static_cast<int>(label) == ignore_index) {
+      return static_cast<T>(0.);
+    }
+    T term1 = (x > 0) ? x : 0;
+    T term2 = x * label;
+    T term3 = std::log(static_cast<T>(1) + std::exp(-(std::abs(x))));
+    return term1 - term2 + term3;
+  }
+
+  int ignore_index;
+};
+
+template <typename T>
+struct SigmoidCrossEntropyWithLogitsBackward {
+  HOSTDEVICE SigmoidCrossEntropyWithLogitsBackward(const int &ignore_index)
+      : ignore_index(ignore_index) {}
+
+  HOSTDEVICE T operator()(const T &x, const T &label) const {
+    if (static_cast<int>(label) == ignore_index) {
+      return static_cast<T>(0.);
+    }
+    T simoid_x = static_cast<T>(1) / (static_cast<T>(1) + std::exp(-x));
+    return simoid_x - label;
+  }
+
+  int ignore_index;
+};
+
 // Out = max(X, 0) - X * Labels + log(1 + exp(-abs(X)))
 template <typename DeviceContext, typename T>
 class SigmoidCrossEntropyWithLogitsKernel : public framework::OpKernel<T> {
  public:
   void Compute(const framework::ExecutionContext &context) const override {
-    const framework::Tensor *X = context.Input<framework::Tensor>("X");
-    const framework::Tensor *Labels = context.Input<framework::Tensor>("Label");
-    framework::Tensor *Out = context.Output<framework::Tensor>("Out");
+    const Tensor *X = context.Input<Tensor>("X");
+    const Tensor *Labels = context.Input<Tensor>("Label");
+    Tensor *Out = context.Output<Tensor>("Out");
     Out->mutable_data<T>(context.GetPlace());
+    int ignore_index = context.Attr<int>("ignore_index");
 
-    auto x = framework::EigenVector<T>::Flatten(*X);
-    auto labels = framework::EigenVector<T>::Flatten(*Labels);
-    auto out = framework::EigenVector<T>::Flatten(*Out);
+    auto x = EigenVector<T>::Flatten(*X);
+    auto labels = EigenVector<T>::Flatten(*Labels);
+    auto out = EigenVector<T>::Flatten(*Out);
     auto &place = *context.device_context<DeviceContext>().eigen_device();
 
-    // term1 = max(x, 0)
-    auto term1 = x.cwiseMax(static_cast<T>(0));
-    // term2 = x * labels
-    auto term2 = x * labels;
-    // term3 = log(1 + exp(-abs(x)))
-    auto term3 = (static_cast<T>(1) + (-(x.abs())).exp()).log();
-
-    out.device(place) = term1 - term2 + term3;
+    out.device(place) = x.binaryExpr(
+        labels, SigmoidCrossEntropyWithLogitsForward<T>(ignore_index));
   }
 };
 
@@ -50,23 +89,23 @@ template <typename DeviceContext, typename T>
 class SigmoidCrossEntropyWithLogitsGradKernel : public framework::OpKernel<T> {
  public:
   void Compute(const framework::ExecutionContext &context) const override {
-    const framework::Tensor *X = context.Input<framework::Tensor>("X");
-    const framework::Tensor *Labels = context.Input<framework::Tensor>("Label");
-    const framework::Tensor *dOut =
-        context.Input<framework::Tensor>(framework::GradVarName("Out"));
-    framework::Tensor *dX =
-        context.Output<framework::Tensor>(framework::GradVarName("X"));
+    const Tensor *X = context.Input<Tensor>("X");
+    const Tensor *Labels = context.Input<Tensor>("Label");
+    const Tensor *dOut = context.Input<Tensor>(framework::GradVarName("Out"));
+    Tensor *dX = context.Output<Tensor>(framework::GradVarName("X"));
     dX->mutable_data<T>(context.GetPlace());
 
-    auto x = framework::EigenVector<T>::Flatten(*X);
-    auto labels = framework::EigenVector<T>::Flatten(*Labels);
-    auto dout = framework::EigenVector<T>::Flatten(*dOut);
-    auto dx = framework::EigenVector<T>::Flatten(*dX);
+    auto ignore_index = context.Attr<int>("ignore_index");
+    auto x = EigenVector<T>::Flatten(*X);
+    auto labels = EigenVector<T>::Flatten(*Labels);
+    auto dout = EigenVector<T>::Flatten(*dOut);
+    auto dx = EigenVector<T>::Flatten(*dX);
     auto &place =
         *context.template device_context<DeviceContext>().eigen_device();
 
-    auto sigmoid_x = static_cast<T>(1) / (static_cast<T>(1) + (-x).exp());
-    dx.device(place) = dout * (sigmoid_x - labels);
+    auto diff = x.binaryExpr(labels, SigmoidCrossEntropyWithLogitsBackward<T>(
+                                         static_cast<int>(ignore_index)));
+    dx.device(place) = dout * diff;
   }
 };
 

python/paddle/fluid/layers/nn.py

@@ -172,6 +172,8 @@ __all__ = [
     'lstm',
 ]
 
+kIgnoreIndex = -100
+
 
 def fc(input,
        size,
@@ -1267,7 +1269,7 @@ def dropout(x,
     return out
 
 
-def cross_entropy(input, label, soft_label=False, ignore_index=-100):
+def cross_entropy(input, label, soft_label=False, ignore_index=kIgnoreIndex):
     """
     **Cross Entropy Layer**
 
@@ -1314,7 +1316,7 @@ def cross_entropy(input, label, soft_label=False, ignore_index=-100):
                                            labels. Default: `False`.
         ignore_index (int): Specifies a target value that is ignored and does
                             not contribute to the input gradient. Only valid
-                            if soft_label is set to False. Default: -100
+                            if soft_label is set to False. Default: kIgnoreIndex
 
     Returns:
          A 2-D tensor with shape [N x 1], the cross entropy loss.
@@ -5185,7 +5187,7 @@ def multiplex(inputs, index):
 def softmax_with_cross_entropy(logits,
                                label,
                                soft_label=False,
-                               ignore_index=-100,
+                               ignore_index=kIgnoreIndex,
                                numeric_stable_mode=False,
                                return_softmax=False):
     """
@@ -5243,7 +5245,7 @@ def softmax_with_cross_entropy(logits,
             labels as soft labels. By default, `soft_label` is set to False.
         ignore_index (int): Specifies a target value that is ignored and does
                             not contribute to the input gradient. Only valid
-                            if soft_label is set to False. Default: -100
+                            if soft_label is set to False. Default: kIgnoreIndex
         numeric_stable_mode (bool): A flag to indicate whether to use a more
                                     numerically stable algorithm. Only valid
                                     when soft_label is False and GPU is used.
@@ -8415,13 +8417,17 @@ def mul(x, y, x_num_col_dims=1, y_num_col_dims=1, name=None):
 
 
 @templatedoc()
-def sigmoid_cross_entropy_with_logits(x, label, name=None):
+def sigmoid_cross_entropy_with_logits(x,
+                                      label,
+                                      ignore_index=kIgnoreIndex,
+                                      name=None):
     """
     ${comment}
 
     Args:
         x(${x_type}): ${x_comment}
         label(${label_type}): ${label_comment}
+        ignore_index(&{ignore_index}): ${ignore_index_comment}
         name(basestring|None): Name of the output.
 
     Returns:
@@ -8440,7 +8446,7 @@ def sigmoid_cross_entropy_with_logits(x, label, name=None):
         type="sigmoid_cross_entropy_with_logits",
         inputs={"X": x,
                 "Label": label},
-        attrs={},
+        attrs={"ignore_index": ignore_index},
         outputs={"Out": out})
     return out
 

python/paddle/fluid/tests/unittests/test_layers.py

@@ -170,9 +170,10 @@ class TestBook(unittest.TestCase):
         with program_guard(program):
             dat = layers.data(name='data', shape=[10], dtype='float32')
             lbl = layers.data(name='label', shape=[10], dtype='float32')
+            ignore_index = -1
             self.assertIsNotNone(
                 layers.sigmoid_cross_entropy_with_logits(
-                    x=dat, label=lbl))
+                    x=dat, label=lbl, ignore_index=ignore_index))
         print(str(program))
 
     def test_hsigmoid(self):

python/paddle/fluid/tests/unittests/test_sigmoid_cross_entropy_with_logits_op.py

@@ -56,6 +56,40 @@ class TestSigmoidCrossEntropyWithLogitsOp2(OpTest):
     """Test sigmoid_cross_entropy_with_logit_op with probabalistic label
     """
 
+    def setUp(self):
+        self.op_type = "sigmoid_cross_entropy_with_logits"
+        batch_size = 64
+        num_classes = 20
+        ignore_index = -1
+        self.inputs = {
+            'X': logit(
+                np.random.uniform(0, 1, (batch_size, num_classes))
+                .astype("float32")),
+            'Label': np.random.randint(-1, 2, (batch_size, num_classes))
+            .astype("float32")
+        }
+        self.attrs = {'ignore_index': ignore_index, }
+        # Fw Pass is implemented as elementwise sigmoid followed by
+        # elementwise logistic loss
+        # Label * -log(sigmoid(X)) + (1 - label) * -log(1 - sigmoid(X))
+        sigmoid_X = expit(self.inputs['X'])
+        term1 = self.inputs['Label'] * np.log(sigmoid_X)
+        term2 = (1 - self.inputs['Label']) * np.log(1 - sigmoid_X)
+        out = -term1 - term2
+        out[np.where(self.inputs['Label'] == ignore_index)] = 0
+        self.outputs = {'Out': out}
+
+    def test_check_output(self):
+        self.check_output()
+
+    def test_check_grad(self):
+        self.check_grad(['X'], 'Out')
+
+
+class TestSigmoidCrossEntropyWithLogitsOp3(OpTest):
+    """Test sigmoid_cross_entropy_with_logit_op with probabalistic label
+    """
+
     def setUp(self):
         self.op_type = "sigmoid_cross_entropy_with_logits"
         batch_size = 64