fix adam op for selected rows

Author: jacquesqiao

paddle/fluid/operators/adam_op.cc

@@ -56,9 +56,12 @@ class AdamOp : public framework::OperatorWithKernel {
                       "Beta2 power accumulator should have 1 dimension");
 
     auto param_dims = ctx->GetInputDim("Param");
-    PADDLE_ENFORCE_EQ(
-        param_dims, ctx->GetInputDim("Grad"),
-        "Param and Grad input of AdamOp should have same dimension");
+    if (ctx->GetInputsVarType("Grad")[0] ==
+        framework::proto::VarType::LOD_TENSOR) {
+      PADDLE_ENFORCE_EQ(
+          param_dims, ctx->GetInputDim("Grad"),
+          "Param and Grad input of AdamOp should have same dimension");
+    }
     PADDLE_ENFORCE_EQ(
         param_dims, ctx->GetInputDim("Moment1"),
         "Param and Moment1 input of AdamOp should have same dimension");