introduce DensePackAttrs to avoid breaking dense op

Author: masahi

include/tvm/relay/attrs/nn.h

@@ -992,11 +992,26 @@ struct DenseAttrs : public tvm::AttrsNode<DenseAttrs> {
   IndexExpr units;
   tvm::String auto_scheduler_rewritten_layout;  // The layout after auto-scheduler's layout rewrite
   DataType out_dtype;
-  tvm::String weight_layout;
 
   TVM_DECLARE_ATTRS(DenseAttrs, "relay.attrs.DenseAttrs") {
     TVM_ATTR_FIELD(units).describe("Number of hidden units of the dense transformation.");
 
+    // use 0 bits to indicate none.
+    TVM_ATTR_FIELD(out_dtype)
+        .set_default(NullValue<DataType>())
+        .describe("Output data type, set to explicit type under mixed precision setting");
+  }
+};
+
+/*! \brief Attributes for dense_pack operator */
+struct DensePackAttrs : public tvm::AttrsNode<DensePackAttrs> {
+  IndexExpr units;
+  DataType out_dtype;
+  tvm::String weight_layout;
+
+  TVM_DECLARE_ATTRS(DensePackAttrs, "relay.attrs.DensePackAttrs") {
+    TVM_ATTR_FIELD(units).describe("Number of hidden units of the dense transformation.");
+
     // use 0 bits to indicate none.
     TVM_ATTR_FIELD(out_dtype)
         .set_default(NullValue<DataType>())

src/relay/op/nn/nn.cc

@@ -233,10 +233,12 @@ RELAY_REGISTER_OP("nn.dense")
 // ------------------- relay.nn.dense
 
 // ------------------- relay.nn.contrib_dense_pack
+TVM_REGISTER_NODE_TYPE(DensePackAttrs);
+
 // Positional relay function to create dense_pack operator used by frontend FFI.
 Expr MakeDensePack(Expr data, Expr weight, tvm::String weight_layout, IndexExpr units,
                    DataType out_dtype) {
-  auto attrs = make_object<DenseAttrs>();
+  auto attrs = make_object<DensePackAttrs>();
   attrs->units = units;
   attrs->out_dtype = out_dtype;
   attrs->weight_layout = std::move(weight_layout);
@@ -253,7 +255,7 @@ bool DensePackRel(const Array<Type>& types, int num_inputs, const Attrs& attrs,
   const auto* weight = types[1].as<TensorTypeNode>();
   if (data == nullptr || weight == nullptr) return false;
 
-  const DenseAttrs* param = attrs.as<DenseAttrs>();
+  const DensePackAttrs* param = attrs.as<DensePackAttrs>();
   ICHECK(param != nullptr);
 
   ICHECK_EQ(data->shape.size(), 2) << "Only 2D data is supported";
@@ -275,7 +277,7 @@ InferCorrectLayoutOutput DensePackInferCorrectLayout(const Attrs& attrs,
                                                      const Array<Layout>& new_in_layouts,
                                                      const Array<Layout>& old_in_layouts,
                                                      const Array<tvm::relay::Type>& old_in_types) {
-  auto params = attrs.as<DenseAttrs>();
+  auto params = attrs.as<DensePackAttrs>();
   ICHECK(params);
   return InferCorrectLayoutOutput({"NC", params->weight_layout}, {"NC"}, attrs);
 }