[REFACTOR] Replace TensorObj and TensorValue with NDArray (#4643)

* replace TensorObj and TensorValue with NDArray

* NodeBase to Object in Python

* rebase

docs/api/python/dev.rst

@@ -20,17 +20,14 @@ Developer API
 This page contains modules that are used by developers of TVM.
 Many of these APIs are PackedFunc registered in C++ backend.
 
-tvm.node
-~~~~~~~~
-.. automodule:: tvm.node
-
-.. autoclass:: tvm.node.NodeBase
-    :members:
+tvm.object
+~~~~~~~~~~
+.. automodule:: tvm.object
 
-.. autoclass:: tvm.node.Node
+.. autoclass:: tvm.object.Object
     :members:
 
-.. autofunction:: tvm.register_node
+.. autofunction:: tvm.register_object
 
 tvm.expr
 ~~~~~~~~

docs/dev/codebase_walkthrough.rst

@@ -55,18 +55,18 @@ We use a simple example that uses the low level TVM API directly. The example is
    B = tvm.placeholder((n,), name='B')
    C = tvm.compute(A.shape, lambda i: A[i] + B[i], name="C")
 
-Here, types of ``A``, ``B``, ``C`` are ``tvm.tensor.Tensor``, defined in ``python/tvm/tensor.py``. The Python ``Tensor`` is backed by C++ ``Tensor``, implemented in ``include/tvm/tensor.h`` and ``src/lang/tensor.cc``. All Python types in TVM can be thought of as a handle to the underlying C++ type with the same name. If you look at the definition of Python ``Tensor`` type below, you can see it is a subclass of ``NodeBase``.
+Here, types of ``A``, ``B``, ``C`` are ``tvm.tensor.Tensor``, defined in ``python/tvm/tensor.py``. The Python ``Tensor`` is backed by C++ ``Tensor``, implemented in ``include/tvm/tensor.h`` and ``src/lang/tensor.cc``. All Python types in TVM can be thought of as a handle to the underlying C++ type with the same name. If you look at the definition of Python ``Tensor`` type below, you can see it is a subclass of ``Object``.
 
 ::
 
-   @register_node
-   class Tensor(NodeBase, _expr.ExprOp):
+   @register_object
+   class Tensor(Object, _expr.ExprOp):
        """Tensor object, to construct, see function.Tensor"""
 
        def __call__(self, *indices):
           ...
 
-The Node system is the basis of exposing C++ types to frontend languages, including Python. The way TVM implements Python wrapping is not straightforward. It is briefly covered in `this document <https://docs.tvm.ai/dev/runtime.html#tvm-node-and-compiler-stack>`_, and details are in ``python/tvm/_ffi/`` if you are interested.
+The object protocol is the basis of exposing C++ types to frontend languages, including Python. The way TVM implements Python wrapping is not straightforward. It is briefly covered in `this document <https://docs.tvm.ai/dev/runtime.html#tvm-node-and-compiler-stack>`_, and details are in ``python/tvm/_ffi/`` if you are interested.
 
 ``Tensor`` is created by functions in ``python/tvm/api.py``, which in turn calls into C++ functions exposed in ``src/api/api_lang.cc``. All C++ functions that are callable from Python are exposed in the ``src/api`` subdirectory. For example, the ``tvm.compute()`` function above calls into ``_ComputeOp`` API exposed in ``src/api/api_lang.cc``:
 

include/tvm/relay/interpreter.h

@@ -37,15 +37,11 @@
 #include <tvm/build_module.h>
 #include <tvm/relay/module.h>
 #include <tvm/relay/expr.h>
+#include <tvm/runtime/object.h>
 
 namespace tvm {
 namespace relay {
 
-/*!
- * \brief A Relay value.
- */
-class Value;
-
 /*!
  *\brief Create a Interpreter function that can
  *  evaluate an expression and produce a value.
@@ -65,39 +61,21 @@ class Value;
  * \param target Compiler target flag to compile the functions on the context.
  * \return A function that takes in an expression and returns a value.
  */
-runtime::TypedPackedFunc<Value(Expr)>
+runtime::TypedPackedFunc<ObjectRef(Expr)>
 CreateInterpreter(Module mod, DLContext context, Target target);
 
-/*! \brief The base container type of Relay values. */
-class ValueNode : public RelayNode {
- public:
-  static constexpr const char* _type_key = "relay.Value";
-  TVM_DECLARE_BASE_OBJECT_INFO(ValueNode, RelayNode);
-};
-
-class Value : public ObjectRef {
- public:
-  Value() {}
-  explicit Value(ObjectPtr<Object> n) : ObjectRef(n) {}
-  const ValueNode* operator->() const {
-    return static_cast<const ValueNode*>(get());
-  }
-
-  using ContainerType = ValueNode;
-};
-
 /*! \brief A Relay closure, i.e a scope and a function. */
 class Closure;
 
 /*! \brief The container type of Closures. */
-class ClosureNode : public ValueNode {
+class ClosureNode : public Object {
  public:
   /*! \brief The set of free variables in the closure.
    *
    * These are the captured variables which are required for
    * evaluation when we call the closure.
    */
-  tvm::Map<Var, Value> env;
+  tvm::Map<Var, ObjectRef> env;
   /*! \brief The function which implements the closure.
    *
    * \note May reference the variables contained in the env.
@@ -111,22 +89,22 @@ class ClosureNode : public ValueNode {
     v->Visit("func", &func);
   }
 
-  TVM_DLL static Closure make(tvm::Map<Var, Value> env, Function func);
+  TVM_DLL static Closure make(tvm::Map<Var, ObjectRef> env, Function func);
 
   static constexpr const char* _type_key = "relay.Closure";
-  TVM_DECLARE_FINAL_OBJECT_INFO(ClosureNode, ValueNode);
+  TVM_DECLARE_FINAL_OBJECT_INFO(ClosureNode, Object);
 };
 
-class Closure : public Value {
+class Closure : public ObjectRef {
  public:
-  TVM_DEFINE_OBJECT_REF_METHODS(Closure, Value, ClosureNode);
+  TVM_DEFINE_OBJECT_REF_METHODS(Closure, ObjectRef, ClosureNode);
 };
 
 /*! \brief A Relay Recursive Closure. A closure that has a name. */
 class RecClosure;
 
 /*! \brief The container type of RecClosure. */
-class RecClosureNode : public ValueNode {
+class RecClosureNode : public Object {
  public:
   /*! \brief The closure. */
   Closure clos;
@@ -143,89 +121,66 @@ class RecClosureNode : public ValueNode {
   TVM_DLL static RecClosure make(Closure clos, Var bind);
 
   static constexpr const char* _type_key = "relay.RecClosure";
-  TVM_DECLARE_FINAL_OBJECT_INFO(RecClosureNode, ValueNode);
+  TVM_DECLARE_FINAL_OBJECT_INFO(RecClosureNode, Object);
 };
 
-class RecClosure : public Value {
+class RecClosure : public ObjectRef {
  public:
-  TVM_DEFINE_OBJECT_REF_METHODS(RecClosure, Value, RecClosureNode);
+  TVM_DEFINE_OBJECT_REF_METHODS(RecClosure, ObjectRef, RecClosureNode);
 };
 
 /*! \brief A tuple value. */
 class TupleValue;
 
 /*! \brief Tuple (x, ... y). */
-struct TupleValueNode : ValueNode {
-  tvm::Array<Value> fields;
+struct TupleValueNode : Object {
+  tvm::Array<ObjectRef> fields;
 
   TupleValueNode() {}
 
   void VisitAttrs(tvm::AttrVisitor* v) { v->Visit("fields", &fields); }
 
-  TVM_DLL static TupleValue make(tvm::Array<Value> value);
+  TVM_DLL static TupleValue make(tvm::Array<ObjectRef> value);
 
   static constexpr const char* _type_key = "relay.TupleValue";
-  TVM_DECLARE_FINAL_OBJECT_INFO(TupleValueNode, ValueNode);
-};
-
-class TupleValue : public Value {
- public:
-  TVM_DEFINE_OBJECT_REF_METHODS(TupleValue, Value, TupleValueNode);
-};
-
-/*! \brief A tensor value. */
-class TensorValue;
-
-/*! \brief The tensor value container, wrapping an NDArray. */
-struct TensorValueNode : ValueNode {
-  runtime::NDArray data;
-
-  TensorValueNode() {}
-
-  void VisitAttrs(tvm::AttrVisitor* v) { v->Visit("data", &data); }
-
-  /*! \brief Build a value from an NDArray. */
-  TVM_DLL static TensorValue make(runtime::NDArray data);
-
-  static constexpr const char* _type_key = "relay.TensorValue";
-  TVM_DECLARE_FINAL_OBJECT_INFO(TensorValueNode, ValueNode);
+  TVM_DECLARE_FINAL_OBJECT_INFO(TupleValueNode, Object);
 };
 
-class TensorValue : public Value {
+class TupleValue : public ObjectRef {
  public:
-  TVM_DEFINE_OBJECT_REF_METHODS(TensorValue, Value, TensorValueNode);
+  TVM_DEFINE_OBJECT_REF_METHODS(TupleValue, ObjectRef, TupleValueNode);
 };
 
 /*! \brief A reference value. */
 class RefValue;
 
-struct RefValueNode : ValueNode {
-  mutable Value value;
+struct RefValueNode : Object {
+  mutable ObjectRef value;
 
   RefValueNode() {}
 
   void VisitAttrs(tvm::AttrVisitor* v) {
     v->Visit("value", &value);
   }
 
-  TVM_DLL static RefValue make(Value val);
+  TVM_DLL static RefValue make(ObjectRef val);
 
   static constexpr const char* _type_key = "relay.RefValue";
-  TVM_DECLARE_FINAL_OBJECT_INFO(RefValueNode, ValueNode);
+  TVM_DECLARE_FINAL_OBJECT_INFO(RefValueNode, Object);
 };
 
-class RefValue : public Value {
+class RefValue : public ObjectRef {
  public:
-  TVM_DEFINE_OBJECT_REF_METHODS(RefValue, Value, RefValueNode);
+  TVM_DEFINE_OBJECT_REF_METHODS(RefValue, ObjectRef, RefValueNode);
 };
 
 /*! \brief An ADT constructor value. */
 class ConstructorValue;
 
-struct ConstructorValueNode : ValueNode {
+struct ConstructorValueNode : Object {
   int32_t tag;
 
-  tvm::Array<Value> fields;
+  tvm::Array<ObjectRef> fields;
 
   /*! \brief Optional field tracking ADT constructor. */
   Constructor constructor;
@@ -237,16 +192,16 @@ struct ConstructorValueNode : ValueNode {
   }
 
   TVM_DLL static ConstructorValue make(int32_t tag,
-                                       tvm::Array<Value> fields,
+                                       tvm::Array<ObjectRef> fields,
                                        Constructor construtor = {});
 
   static constexpr const char* _type_key = "relay.ConstructorValue";
-  TVM_DECLARE_FINAL_OBJECT_INFO(ConstructorValueNode, ValueNode);
+  TVM_DECLARE_FINAL_OBJECT_INFO(ConstructorValueNode, Object);
 };
 
-class ConstructorValue : public Value {
+class ConstructorValue : public ObjectRef {
  public:
-  TVM_DEFINE_OBJECT_REF_METHODS(ConstructorValue, Value, ConstructorValueNode);
+  TVM_DEFINE_OBJECT_REF_METHODS(ConstructorValue, ObjectRef, ConstructorValueNode);
 };
 
 }  // namespace relay

include/tvm/runtime/vm.h

@@ -36,25 +36,6 @@ namespace tvm {
 namespace runtime {
 namespace vm {
 
-/*! \brief An object containing an NDArray. */
-class TensorObj : public Object {
- public:
-  /*! \brief The NDArray. */
-  NDArray data;
-
-  static constexpr const uint32_t _type_index = TypeIndex::kVMTensor;
-  static constexpr const char* _type_key = "vm.Tensor";
-  TVM_DECLARE_FINAL_OBJECT_INFO(TensorObj, Object);
-};
-
-/*! \brief reference to tensor. */
-class Tensor : public ObjectRef {
- public:
-  explicit Tensor(NDArray data);
-
-  TVM_DEFINE_OBJECT_REF_METHODS(Tensor, ObjectRef, TensorObj);
-};
-
 /*! \brief An object representing a closure. */
 class ClosureObj : public Object {
  public:

python/tvm/__init__.py

@@ -34,7 +34,7 @@
 from . import container
 from . import schedule
 from . import module
-from . import node
+from . import object
 from . import attrs
 from . import ir_builder
 from . import target
@@ -55,7 +55,7 @@
 from .api import *
 from .intrin import *
 from .tensor_intrin import decl_tensor_intrin
-from .node import register_node
+from .object import register_object
 from .ndarray import register_extension
 from .schedule import create_schedule
 from .build_module import build, lower, build_config

python/tvm/_ffi/_ctypes/function.py

@@ -25,14 +25,14 @@
 
 from ..base import _LIB, get_last_ffi_error, py2cerror
 from ..base import c_str, string_types
-from ..node_generic import convert_to_node, NodeGeneric
+from ..object_generic import convert_to_object, ObjectGeneric
 from ..runtime_ctypes import TVMType, TVMByteArray, TVMContext
 from . import ndarray as _nd
 from .ndarray import NDArrayBase, _make_array
 from .types import TVMValue, TypeCode
 from .types import TVMPackedCFunc, TVMCFuncFinalizer
 from .types import RETURN_SWITCH, C_TO_PY_ARG_SWITCH, _wrap_arg_func, _ctx_to_int64
-from .object import ObjectBase, _set_class_node
+from .object import ObjectBase, _set_class_object
 from . import object as _object
 
 FunctionHandle = ctypes.c_void_p
@@ -144,8 +144,8 @@ def _make_tvm_args(args, temp_args):
         elif isinstance(arg, string_types):
             values[i].v_str = c_str(arg)
             type_codes[i] = TypeCode.STR
-        elif isinstance(arg, (list, tuple, dict, NodeGeneric)):
-            arg = convert_to_node(arg)
+        elif isinstance(arg, (list, tuple, dict, ObjectGeneric)):
+            arg = convert_to_object(arg)
             values[i].v_handle = arg.handle
             type_codes[i] = TypeCode.OBJECT_HANDLE
             temp_args.append(arg)
@@ -256,7 +256,6 @@ def _handle_return_func(x):
 
 _CLASS_MODULE = None
 _CLASS_FUNCTION = None
-_CLASS_OBJECT = None
 
 def _set_class_module(module_class):
     """Initialize the module."""
@@ -266,7 +265,3 @@ def _set_class_module(module_class):
 def _set_class_function(func_class):
     global _CLASS_FUNCTION
     _CLASS_FUNCTION = func_class
-
-def _set_class_object(obj_class):
-    global _CLASS_OBJECT
-    _CLASS_OBJECT = obj_class

python/tvm/_ffi/_ctypes/object.py

@@ -30,11 +30,11 @@
 """Maps object type to its constructor"""
 OBJECT_TYPE = {}
 
-_CLASS_NODE = None
+_CLASS_OBJECT = None
 
-def _set_class_node(node_class):
-    global _CLASS_NODE
-    _CLASS_NODE = node_class
+def _set_class_object(object_class):
+    global _CLASS_OBJECT
+    _CLASS_OBJECT = object_class
 
 
 def _register_object(index, cls):
@@ -51,7 +51,7 @@ def _return_object(x):
         handle = ObjectHandle(handle)
     tindex = ctypes.c_uint()
     check_call(_LIB.TVMObjectGetTypeIndex(handle, ctypes.byref(tindex)))
-    cls = OBJECT_TYPE.get(tindex.value, _CLASS_NODE)
+    cls = OBJECT_TYPE.get(tindex.value, _CLASS_OBJECT)
     # Avoid calling __init__ of cls, instead directly call __new__
     # This allows child class to implement their own __init__
     obj = cls.__new__(cls)