Merge pull request #16798 from phlrain/softmax_cross_support_high_rank

softmax cross entropy support high rank

Author: phlrain

paddle/fluid/operators/softmax_with_cross_entropy_op.cc

@@ -106,24 +106,36 @@ class SoftmaxWithCrossEntropyOp : public framework::OperatorWithKernel {
 
     auto logits_dims = ctx->GetInputDim("Logits");
     auto labels_dims = ctx->GetInputDim("Label");
+
+    int rank = logits_dims.size();
     PADDLE_ENFORCE_EQ(
-        logits_dims.size(), 2UL,
-        "The input of softmax_with_cross_entropy should be a 2-D tensor.");
-    PADDLE_ENFORCE_EQ(labels_dims.size(), 2UL,
-                      "The labels should be a 2-D tensor.");
+        rank, labels_dims.size(),
+        "Input(logits) and Input(Label) shall have the same rank.");
+    bool check = ctx->IsRuntime() || (framework::product(logits_dims) > 0 &&
+                                      framework::product(labels_dims) > 0);
+    if (check) {
+      PADDLE_ENFORCE_EQ(framework::slice_ddim(logits_dims, 0, rank - 1),
+                        framework::slice_ddim(labels_dims, 0, rank - 1),
+                        "Input(X) and Input(Label) shall have the same shape "
+                        "except the last dimension.");
+    }
 
     if (ctx->Attrs().Get<bool>("soft_label")) {
-      PADDLE_ENFORCE_EQ(logits_dims[1], labels_dims[1],
-                        "If Attr(soft_label) == true, the 2nd dimension of "
-                        "Input(X) and Input(Label) should be equal.");
+      if (check) {
+        PADDLE_ENFORCE_EQ(logits_dims[rank - 1], labels_dims[rank - 1],
+                          "If Attr(soft_label) == true, the last dimension of "
+                          "Input(X) and Input(Label) should be equal.");
+      }
     } else {
-      PADDLE_ENFORCE_EQ(labels_dims[1], 1UL,
-                        "If Attr(soft_label) == false, the 2nd dimension of "
+      PADDLE_ENFORCE_EQ(labels_dims[rank - 1], 1UL,
+                        "If Attr(softLabel) == false, the last dimension of "
                         "Input(Label) should be 1.");
     }
 
     ctx->SetOutputDim("Softmax", logits_dims);
-    ctx->SetOutputDim("Loss", {logits_dims[0], 1});
+    auto loss_dims = logits_dims;
+    loss_dims[rank - 1] = 1;
+    ctx->SetOutputDim("Loss", loss_dims);
 
     ctx->ShareLoD("Logits", /*->*/ "Softmax");
     ctx->ShareLoD("Logits", /*->*/ "Loss");
@@ -152,16 +164,33 @@ class SoftmaxWithCrossEntropyOpGrad : public framework::OperatorWithKernel {
 
     auto softmax_dims = ctx->GetInputDim("Softmax");
     auto labels_dims = ctx->GetInputDim("Label");
-    PADDLE_ENFORCE_EQ(labels_dims.size(), 2UL,
-                      "The labels should be a 2-D tensor.");
+
+    int rank = softmax_dims.size();
+    PADDLE_ENFORCE_EQ(
+        rank, labels_dims.size(),
+        "Input(logits) and Input(Label) shall have the same rank.");
+    bool check = true;
+    if ((!ctx->IsRuntime()) && (framework::product(softmax_dims) <= 0 ||
+                                framework::product(labels_dims) <= 0)) {
+      check = false;
+    }
+    if (check) {
+      PADDLE_ENFORCE_EQ(
+          framework::slice_ddim(softmax_dims, 0, rank - 1),
+          framework::slice_ddim(labels_dims, 0, rank - 1),
+          "Input(Softmax) and Input(Label) shall have the same shape "
+          "except the last dimension.");
+    }
 
     if (ctx->Attrs().Get<bool>("soft_label")) {
-      PADDLE_ENFORCE_EQ(softmax_dims[1], labels_dims[1],
-                        "When Attr(soft_label) == true, the 2nd dimension of "
-                        "Input(X) and Input(Label) should be equal.");
+      if (check) {
+        PADDLE_ENFORCE_EQ(softmax_dims[rank - 1], labels_dims[rank - 1],
+                          "If Attr(soft_label) == true, the last dimension of "
+                          "Input( Softmax) and Input(Label) should be equal.");
+      }
     } else {
-      PADDLE_ENFORCE_EQ(labels_dims[1], 1UL,
-                        "When Attr(soft_label) == false, the 2nd dimension of "
+      PADDLE_ENFORCE_EQ(labels_dims[rank - 1], 1UL,
+                        "If Attr(softLabel) == false, the last dimension of "
                         "Input(Label) should be 1.");
     }
 

paddle/fluid/operators/softmax_with_cross_entropy_op.cu

@@ -400,24 +400,39 @@ class SoftmaxWithCrossEntropyCUDAKernel : public framework::OpKernel<T> {
 
     auto soft_label = context.Attr<bool>("soft_label");
     auto ignore_index = context.Attr<int>("ignore_index");
+
+    int rank = logits->dims().size();
     if (soft_label) {
-      int batch_size = logits->dims()[0];
-      int feature_size = logits->dims()[1];
+      int batch_size = 1;
+      for (int i = 0; i < rank - 1; ++i) {
+        batch_size *= logits->dims()[i];
+      }
+
+      int feature_size = logits->dims()[rank - 1];
       auto* logits_data = logits->data<T>();
       auto* labels_data = labels->data<T>();
       SoftmaxWithCrossEntropyFusedKernel(
           logits_data, labels_data, softmax_data, loss_data, batch_size,
           feature_size, context.cuda_device_context().stream());
     } else {
       if (!context.Attr<bool>("numeric_stable_mode")) {
-        math::SoftmaxCUDNNFunctor<T>()(context.cuda_device_context(), logits,
-                                       softmax);
+        // reshape to 2d
+        Tensor logits_2d = framework::ReshapeToMatrix(*logits, rank - 1);
+        Tensor softmax_2d = framework::ReshapeToMatrix(*softmax, rank - 1);
+        Tensor loss_2d = framework::ReshapeToMatrix(*loss, rank - 1);
+        Tensor labels_2d = framework::ReshapeToMatrix(*labels, rank - 1);
+
+        math::SoftmaxCUDNNFunctor<T>()(context.cuda_device_context(),
+                                       &logits_2d, &softmax_2d);
         math::CrossEntropyFunctor<platform::CUDADeviceContext, T>()(
-            context.cuda_device_context(), loss, softmax, labels, false,
-            ignore_index);
+            context.cuda_device_context(), &loss_2d, &softmax_2d, &labels_2d,
+            false, ignore_index);
       } else {
-        int batch_size = logits->dims()[0];
-        int feature_size = logits->dims()[1];
+        int batch_size = 1;
+        for (int i = 0; i < rank - 1; ++i) {
+          batch_size *= logits->dims()[i];
+        }
+        int feature_size = logits->dims()[rank - 1];
         auto* logits_data = logits->data<T>();
         auto* labels_data = labels->data<int64_t>();
         HardLabelSoftmaxWithCrossEntropy<T>(
@@ -443,8 +458,13 @@ class SoftmaxWithCrossEntropyGradCUDAKernel : public framework::OpKernel<T> {
                           context.device_context(), logit_grad);
     T* logit_grad_data = logit_grad->data<T>();
 
-    const int batch_size = logit_grad->dims()[0];
-    const int class_num = logit_grad->dims()[1];
+    int rank = logit_grad->dims().size();
+    int batch_size = 1;
+    for (int i = 0; i < rank - 1; ++i) {
+      batch_size *= logit_grad->dims()[i];
+    }
+
+    const int class_num = logit_grad->dims()[rank - 1];
     int block = 512;
     auto stream = context.cuda_device_context().stream();
     auto ignore_index = context.Attr<int>("ignore_index");

paddle/fluid/operators/softmax_with_cross_entropy_op.h

@@ -40,15 +40,22 @@ class SoftmaxWithCrossEntropyKernel : public framework::OpKernel<T> {
     softmax->mutable_data<T>(context.GetPlace());
     loss->mutable_data<T>(context.GetPlace());
 
-    int axis_dim = logits->dims()[logits->dims().size() - 1];
+    // reshape to 2D tensor
+    int rank = logits->dims().size();
+    Tensor logits_2d = framework::ReshapeToMatrix(*logits, rank - 1);
+    Tensor labels_2d = framework::ReshapeToMatrix(*labels, rank - 1);
+    Tensor loss_2d = framework::ReshapeToMatrix(*loss, rank - 1);
+    Tensor softmax_2d = framework::ReshapeToMatrix(*softmax, rank - 1);
+
+    int axis_dim = logits->dims()[rank - 1];
 
     auto& dev_ctx =
         context.template device_context<platform::CPUDeviceContext>();
     math::SoftmaxFunctor<platform::CPUDeviceContext, T, false>()(
-        dev_ctx, axis_dim, logits, softmax);
+        dev_ctx, axis_dim, &logits_2d, &softmax_2d);
     math::CrossEntropyFunctor<platform::CPUDeviceContext, T>()(
-        dev_ctx, loss, softmax, labels, context.Attr<bool>("soft_label"),
-        context.Attr<int>("ignore_index"));
+        dev_ctx, &loss_2d, &softmax_2d, &labels_2d,
+        context.Attr<bool>("soft_label"), context.Attr<int>("ignore_index"));
   }
 };
 
@@ -63,13 +70,19 @@ class SoftmaxWithCrossEntropyGradKernel : public framework::OpKernel<T> {
         context.Output<Tensor>(framework::GradVarName("Logits"));
     logit_grad->ShareDataWith(*context.Input<Tensor>("Softmax"));
 
-    const int class_num = logit_grad->dims()[1];
-    auto out_grad_mat = EigenMatrix<T>::From(*out_grad);
-    auto logit_grad_mat = EigenMatrix<T>::From(*logit_grad);
+    int rank = logit_grad->dims().size();
+    const int class_num = logit_grad->dims()[rank - 1];
+    // reshape to 2d
+    Tensor logit_grad_2d = framework::ReshapeToMatrix(*logit_grad, rank - 1);
+    Tensor out_grad_2d = framework::ReshapeToMatrix(*out_grad, rank - 1);
+
+    auto out_grad_mat = EigenMatrix<T>::From(out_grad_2d);
+    auto logit_grad_mat = EigenMatrix<T>::From(logit_grad_2d);
     auto& place = *context.template device_context<platform::CPUDeviceContext>()
                        .eigen_device();
     if (context.Attr<bool>("soft_label")) {
-      auto lbl_mat = EigenMatrix<T>::From(*labels);
+      Tensor labels_2d = framework::ReshapeToMatrix(*labels, rank - 1);
+      auto lbl_mat = EigenMatrix<T>::From(labels_2d);
       logit_grad_mat.device(place) =
           out_grad_mat.broadcast(Eigen::DSizes<int, 2>(1, class_num)) *
           (logit_grad_mat - lbl_mat);
@@ -78,7 +91,8 @@ class SoftmaxWithCrossEntropyGradKernel : public framework::OpKernel<T> {
           logit_grad_mat *
           out_grad_mat.broadcast(Eigen::DSizes<int, 2>(1, class_num));
 
-      const int batch_size = logit_grad->dims()[0];
+      const int batch_size = logit_grad_2d.dims()[0];
+
       const int64_t* label_data = labels->data<int64_t>();
       T* logit_grad_data = logit_grad->data<T>();
       const T* out_grad_data = out_grad->data<T>();

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

@@ -195,5 +195,144 @@ def initParams(self):
         self.numeric_stable_mode = True
 
 
+class TestSoftmaxWithCrossEntropyOp5(OpTest):
+    """
+    Test softmax with cross entropy operator with ignore_index.
+    """
+
+    def initParams(self):
+        self.numeric_stable_mode = False
+
+    def setUp(self):
+        self.initParams()
+        self.op_type = "softmax_with_cross_entropy"
+        batch_size = [6, 10]
+        class_num = 47
+
+        logits = np.random.uniform(
+            0.1, 1.0, tuple(batch_size + [class_num])).astype("float64")
+        softmax = np.apply_along_axis(stable_softmax, 2, logits)
+        labels = np.random.randint(
+            0, class_num, tuple(batch_size + [1]), dtype="int64")
+        ignore_index = 7
+
+        softmax_2d = np.reshape(softmax, [-1, class_num])
+        labels_2d = np.reshape(labels, [-1, 1])
+        cross_entropy = np.asmatrix(
+            [[-np.log(softmax_2d[i][labels_2d[i][0]])]
+             if labels_2d[i] != ignore_index else [0]
+             for i in range(softmax_2d.shape[0])],
+            dtype="float64")
+
+        cross_entropy = np.reshape(cross_entropy, batch_size)
+
+        output_shape = tuple(batch_size + [1])
+        output_res = cross_entropy.astype("float64")
+        output_res = np.expand_dims(output_res, axis=2)
+        self.inputs = {"Logits": logits, "Label": labels}
+        self.outputs = {
+            "Softmax": softmax.astype("float64"),
+            "Loss": output_res,
+        }
+        self.attrs = {
+            "ignore_index": ignore_index,
+            "numeric_stable_mode": self.numeric_stable_mode
+        }
+
+    def test_check_output(self):
+        self.check_output()
+
+    def test_check_grad(self):
+        self.check_grad(["Logits"], "Loss")
+
+
+class TestSoftmaxWithCrossEntropyOp5NoCudnn(TestSoftmaxWithCrossEntropyOp5):
+    def initParams(self):
+        self.numeric_stable_mode = True
+
+
+class TestSoftmaxWithCrossEntropyOp6(OpTest):
+    """
+    Test softmax with cross entropy operator with soft labels.
+    """
+
+    def setUp(self):
+        self.op_type = "softmax_with_cross_entropy"
+        batch_size = [6, 10]
+        class_num = 37
+
+        logits = np.random.uniform(
+            0.1, 1.0, tuple(batch_size + [class_num])).astype("float64")
+        softmax = np.apply_along_axis(stable_softmax, 2, logits)
+        labels = np.random.uniform(
+            0.1, 1.0, tuple(batch_size + [class_num])).astype("float64")
+        labels /= np.sum(labels, axis=2, keepdims=True)
+
+        cross_entropy = (-labels * np.log(softmax)).sum(
+            axis=2, keepdims=True).astype("float64")
+
+        self.inputs = {"Logits": logits, "Label": labels}
+        self.outputs = {
+            "Softmax": softmax.astype("float64"),
+            "Loss": cross_entropy.astype("float64")
+        }
+        self.attrs = {"soft_label": True}
+
+    def test_check_output(self):
+        self.check_output()
+
+    def test_check_grad(self):
+        self.check_grad(["Logits"], "Loss")
+
+
+class TestSoftmaxWithCrossEntropyOpFp16_2(TestSoftmaxWithCrossEntropyOp):
+    def initParams(self):
+        self.numeric_stable_mode = False
+        self.dtype = np.float16
+
+    def setUp(self):
+        self.initParams()
+        self.op_type = "softmax_with_cross_entropy"
+        batch_size = [64, 10]
+        class_num = 37
+
+        # NOTE: numpy float16 have very low accuracy, use float32 for numpy check.
+        logits = np.random.uniform(
+            0.1, 1.0, tuple(batch_size + [class_num])).astype(np.float32)
+        softmax = np.apply_along_axis(stable_softmax, 2, logits)
+        labels = np.random.randint(
+            0, class_num, tuple(batch_size + [1]), dtype="int64")
+
+        softmax_2d = np.reshape(softmax, [-1, class_num])
+        labels_2d = np.reshape(labels, [-1, 1])
+
+        cross_entropy = np.asmatrix(
+            [[-np.log(softmax_2d[i][labels_2d[i][0]])]
+             for i in range(softmax_2d.shape[0])],
+            dtype=np.float32)
+
+        cross_entropy = np.reshape(cross_entropy, batch_size)
+        output_shape = tuple(batch_size + [1])
+        output_res = cross_entropy.astype(self.dtype)
+        output_res = np.expand_dims(output_res, axis=2)
+        self.inputs = {"Logits": logits, "Label": labels}
+
+        self.inputs = {
+            "Logits": logits.astype(self.dtype).view(np.uint16),
+            "Label": labels
+        }
+        self.outputs = {
+            "Softmax": softmax.astype(self.dtype),
+            "Loss": output_res,
+        }
+        self.attrs = {"numeric_stable_mode": self.numeric_stable_mode}
+
+    def test_check_output(self):
+        self.check_output(atol=1e-2)
+
+    def test_check_grad(self):
+        self.check_grad(["Logits"], "Loss", max_relative_error=0.1)
+
+
 if __name__ == "__main__":
     unittest.main()