fix sparse gradient clip

paddle/fluid/operators/clip_op.h

@@ -16,6 +16,7 @@ limitations under the License. */
 
 #include "paddle/fluid/framework/eigen.h"
 #include "paddle/fluid/framework/op_registry.h"
+#include "paddle/fluid/operators/math/selected_rows_functor.h"
 #include "paddle/fluid/platform/transform.h"
 
 namespace paddle {
@@ -61,14 +62,32 @@ class ClipKernel : public framework::OpKernel<T> {
   void Compute(const framework::ExecutionContext& context) const override {
     auto max = context.Attr<T>("max");
     auto min = context.Attr<T>("min");
-    auto* x = context.Input<Tensor>("X");
-    auto* out = context.Output<Tensor>("Out");
+    auto* x_var = context.InputVar("X");
+    if (x_var->IsType<framework::LoDTensor>()) {
+      auto* x = context.Input<framework::LoDTensor>("X");
+      auto* out = context.Output<framework::LoDTensor>("Out");
       T* out_data = out->mutable_data<T>(context.GetPlace());
       const T* x_data = x->data<T>();
       int64_t numel = x->numel();
       Transform<DeviceContext> trans;
       trans(context.template device_context<DeviceContext>(), x_data,
             x_data + numel, out_data, ClipFunctor<T>(min, max));
+    } else if (x_var->IsType<framework::SelectedRows>()) {
+      auto* x = context.Input<framework::SelectedRows>("X");
+      auto* out = context.Output<framework::SelectedRows>("Out");
+      PADDLE_ENFORCE_NE(x, out,
+                        "Inplace clip is not allowed when x is SelectedRows");
+      math::scatter::MergeAdd<DeviceContext, T> merge_func;
+      merge_func(context.template device_context<DeviceContext>(), *x, out);
+      auto* out_tensor = out->mutable_value();
+      auto* out_data = out_tensor->data<T>();
+      int64_t numel = out_tensor->numel();
+      Transform<DeviceContext> trans;
+      trans(context.template device_context<DeviceContext>(), out_data,
+            out_data + numel, out_data, ClipFunctor<T>(min, max));
+    } else {
+      PADDLE_THROW("ClipOp only supports LoDTensor and SelectedRows");
+    }
   }
 };
 
@@ -78,10 +97,12 @@ class ClipGradKernel : public framework::OpKernel<T> {
   void Compute(const framework::ExecutionContext& context) const override {
     auto max = context.Attr<T>("max");
     auto min = context.Attr<T>("min");
-    auto* d_out = context.Input<Tensor>(framework::GradVarName("Out"));
-    auto* d_x = context.Output<Tensor>(framework::GradVarName("X"));
+    auto* d_out =
+        context.Input<framework::LoDTensor>(framework::GradVarName("Out"));
+    auto* d_x =
+        context.Output<framework::LoDTensor>(framework::GradVarName("X"));
     if (d_x != nullptr) {
-      auto* x = context.Input<Tensor>("X");
+      auto* x = context.Input<framework::LoDTensor>("X");
       int64_t numel = d_out->numel();
       auto* d_x_data = d_x->mutable_data<T>(context.GetPlace());
       const T* d_out_data = d_out->data<T>();

paddle/fluid/operators/math/selected_rows_functor.cu

@@ -236,7 +236,7 @@ template <typename T, int block_size>
 __global__ void MergeAddKernel(const T* input, const int64_t* input_rows,
                                T* out, const int64_t* out_rows,
                                size_t out_rows_size, int64_t row_numel) {
-  const int ty = blockIdx.y;
+  const int ty = blockIdx.x;
   int tid = threadIdx.x;
   __shared__ size_t out_idx;
 
@@ -291,12 +291,9 @@ struct MergeAdd<platform::CUDADeviceContext, T> {
 
     const int block_size = 256;
     dim3 threads(block_size, 1);
-    dim3 grid1(1, input_rows.size());
+    dim3 grid1(input_rows.size(), 1);
 
-    MergeAddKernel<
-        T, 256><<<grid1, threads, 0,
-                  reinterpret_cast<const platform::CUDADeviceContext&>(context)
-                      .stream()>>>(
+    MergeAddKernel<T, 256><<<grid1, threads, 0, context.stream()>>>(
         input_data, input_rows.CUDAData(context.GetPlace()), out_data,
         out.mutable_rows()->CUDAMutableData(context.GetPlace()),
         out.rows().size(), input_width);