[REFACTOR][PY] Establish tvm.runtime (apache#4818)

* [REFACTOR][PY] Establish tvm.runtime

This PR establishes the tvm.runtime namespace that contains the core runtime data structures.
The top-level API are kept inact for now via re-exporting.

We will followup later to cleanup some of the top-level APIs.

* Fix ndarray name

python/tvm/__init__.py

@@ -15,19 +15,29 @@
 # specific language governing permissions and limitations
 # under the License.
 # pylint: disable=redefined-builtin, wildcard-import
-"""TVM: Low level DSL/IR stack for tensor computation."""
+"""TVM: Open Deep Learning Compiler Stack."""
 import multiprocessing
 import sys
 import traceback
 
-# import ffi related features
+# top-level alias
+# tvm._ffi
 from ._ffi.base import TVMError, __version__
-from ._ffi.runtime_ctypes import TypeCode, TVMType
-from ._ffi.ndarray import TVMContext
-from ._ffi.packed_func import PackedFunc as Function
+from ._ffi.runtime_ctypes import TypeCode, DataType
 from ._ffi.registry import register_object, register_func, register_extension
-from ._ffi.object import Object
 
+# top-level alias
+# tvm.runtime
+from .runtime.object import Object
+from .runtime.packed_func import PackedFunc as Function
+from .runtime.ndarray import context, cpu, gpu, opencl, cl, vulkan, metal, mtl
+from .runtime.ndarray import vpi, rocm, opengl, ext_dev, micro_dev
+from .runtime import module
+from .runtime import ndarray
+# pylint: disable=reimported
+from .runtime import ndarray as nd
+
+# others
 from . import tensor
 from . import arith
 from . import expr
@@ -37,7 +47,7 @@
 from . import codegen
 from . import container
 from . import schedule
-from . import module
+
 from . import attrs
 from . import ir_builder
 from . import target
@@ -47,9 +57,6 @@
 from . import error
 from . import datatype
 
-from . import ndarray as nd
-from .ndarray import context, cpu, gpu, opencl, cl, vulkan, metal, mtl
-from .ndarray import vpi, rocm, opengl, ext_dev, micro_dev
 
 from .api import *
 from .intrin import *

python/tvm/_ffi/_ctypes/packed_func.py

@@ -23,7 +23,7 @@
 
 from ..base import _LIB, get_last_ffi_error, py2cerror, check_call
 from ..base import c_str, string_types
-from ..runtime_ctypes import TVMType, TVMByteArray, TVMContext
+from ..runtime_ctypes import DataType, TVMByteArray, TVMContext
 from . import ndarray as _nd
 from .ndarray import NDArrayBase, _make_array
 from .types import TVMValue, TypeCode
@@ -132,7 +132,7 @@ def _make_tvm_args(args, temp_args):
         elif isinstance(arg, Number):
             values[i].v_float64 = arg
             type_codes[i] = TypeCode.FLOAT
-        elif isinstance(arg, TVMType):
+        elif isinstance(arg, DataType):
             values[i].v_str = c_str(str(arg))
             type_codes[i] = TypeCode.STR
         elif isinstance(arg, TVMContext):

python/tvm/_ffi/_cython/packed_func.pxi

@@ -20,7 +20,7 @@ import traceback
 from cpython cimport Py_INCREF, Py_DECREF
 from numbers import Number, Integral
 from ..base import string_types, py2cerror
-from ..runtime_ctypes import TVMType, TVMContext, TVMByteArray
+from ..runtime_ctypes import DataType, TVMContext, TVMByteArray
 
 
 cdef void tvm_callback_finalize(void* fhandle):
@@ -129,7 +129,7 @@ cdef inline int make_arg(object arg,
     elif isinstance(arg, Number):
         value[0].v_float64 = arg
         tcode[0] = kFloat
-    elif isinstance(arg, TVMType):
+    elif isinstance(arg, DataType):
         tstr = c_str(str(arg))
         value[0].v_str = tstr
         tcode[0] = kTVMStr

python/tvm/_ffi/runtime_ctypes.py

@@ -48,7 +48,7 @@ class TVMByteArray(ctypes.Structure):
     _fields_ = [("data", ctypes.POINTER(ctypes.c_byte)),
                 ("size", ctypes.c_size_t)]
 
-class TVMType(ctypes.Structure):
+class DataType(ctypes.Structure):
     """TVM datatype structure"""
     _fields_ = [("type_code", ctypes.c_uint8),
                 ("bits", ctypes.c_uint8),
@@ -60,7 +60,7 @@ class TVMType(ctypes.Structure):
         4 : 'handle'
     }
     def __init__(self, type_str):
-        super(TVMType, self).__init__()
+        super(DataType, self).__init__()
         if isinstance(type_str, np.dtype):
             type_str = str(type_str)
 
@@ -104,8 +104,8 @@ def __init__(self, type_str):
     def __repr__(self):
         if self.bits == 1 and self.lanes == 1:
             return "bool"
-        if self.type_code in TVMType.CODE2STR:
-            type_name = TVMType.CODE2STR[self.type_code]
+        if self.type_code in DataType.CODE2STR:
+            type_name = DataType.CODE2STR[self.type_code]
         else:
             type_name = "custom[%s]" % \
                         _api_internal._datatype_get_type_name(self.type_code)
@@ -263,7 +263,7 @@ class TVMArray(ctypes.Structure):
     _fields_ = [("data", ctypes.c_void_p),
                 ("ctx", TVMContext),
                 ("ndim", ctypes.c_int),
-                ("dtype", TVMType),
+                ("dtype", DataType),
                 ("shape", ctypes.POINTER(tvm_shape_index_t)),
                 ("strides", ctypes.POINTER(tvm_shape_index_t)),
                 ("byte_offset", ctypes.c_uint64)]

python/tvm/api.py

@@ -20,10 +20,10 @@
 
 import tvm._ffi
 
+from tvm.runtime import convert, const, DataType
 from ._ffi.base import string_types, TVMError
-from ._ffi.object_generic import convert, const
 from ._ffi.registry import register_func, get_global_func, extract_ext_funcs
-from ._ffi.runtime_ctypes import TVMType
+
 from . import _api_internal
 from . import make as _make
 from . import expr as _expr

python/tvm/arith.py

@@ -15,10 +15,9 @@
 # specific language governing permissions and limitations
 # under the License.
 """Arithmetic data structure and utility"""
-from __future__ import absolute_import as _abs
 import tvm._ffi
+from tvm.runtime import Object
 
-from ._ffi.object import Object
 from . import _api_internal
 
 class IntSet(Object):

python/tvm/attrs.py

@@ -17,7 +17,7 @@
 """ TVM Attribute module, which is mainly used for defining attributes of operators"""
 import tvm._ffi
 
-from ._ffi.object import Object
+from tvm.runtime import Object
 from . import _api_internal
 
 

python/tvm/build_module.py

@@ -22,7 +22,7 @@
 import warnings
 import tvm._ffi
 
-from ._ffi.object import Object
+from tvm.runtime import Object, ndarray
 from . import api
 from . import _api_internal
 from . import tensor
@@ -33,7 +33,6 @@
 from . import container
 from . import module
 from . import codegen
-from . import ndarray
 from . import target as _target
 from . import make
 

python/tvm/container.py

@@ -17,9 +17,9 @@
 """Container data structures used in TVM DSL."""
 import tvm._ffi
 
-from tvm import ndarray as _nd
+from tvm.runtime import Object, ObjectTypes
+from tvm.runtime.container import getitem_helper
 from . import _api_internal
-from ._ffi.object import Object, getitem_helper
 
 
 @tvm._ffi.register_object
@@ -31,23 +31,9 @@ class Array(Object):
     to Array during tvm function call.
     You may get Array in return values of TVM function call.
     """
-    def __getitem__(self, i):
-        if isinstance(i, slice):
-            start = i.start if i.start is not None else 0
-            stop = i.stop if i.stop is not None else len(self)
-            step = i.step if i.step is not None else 1
-            if start < 0:
-                start += len(self)
-            if stop < 0:
-                stop += len(self)
-            return [self[idx] for idx in range(start, stop, step)]
-
-        if i < -len(self) or i >= len(self):
-            raise IndexError("Array index out of range. Array size: {}, got index {}"
-                             .format(len(self), i))
-        if i < 0:
-            i += len(self)
-        return _api_internal._ArrayGetItem(self, i)
+    def __getitem__(self, idx):
+        return getitem_helper(
+            self, _api_internal._ArrayGetItem, len(self), idx)
 
     def __len__(self):
         return _api_internal._ArraySize(self)
@@ -133,7 +119,7 @@ class ADT(Object):
     """
     def __init__(self, tag, fields):
         for f in fields:
-            assert isinstance(f, (Object, _nd.NDArray)), "Expect object or " \
+            assert isinstance(f, ObjectTypes), "Expect object or " \
             "tvm NDArray type, but received : {0}".format(type(f))
         self.__init_handle_by_constructor__(_ADT, tag, *fields)
 
@@ -164,7 +150,7 @@ def tuple_object(fields=None):
     """
     fields = fields if fields else []
     for f in fields:
-        assert isinstance(f, (Object, _nd.NDArray)), "Expect object or tvm " \
+        assert isinstance(f, ObjectTypes), "Expect object or tvm " \
         "NDArray type, but received : {0}".format(type(f))
     return _Tuple(*fields)
 

python/tvm/contrib/debugger/debug_runtime.py

@@ -23,7 +23,7 @@
 
 from tvm._ffi.base import string_types
 from tvm.contrib import graph_runtime
-from tvm.ndarray import array
+from tvm.runtime.ndarray import array
 from . import debug_result
 
 _DUMP_ROOT_PREFIX = "tvmdbg_"

python/tvm/contrib/nvcc.py

@@ -21,8 +21,9 @@
 import subprocess
 import os
 import warnings
+from tvm.runtime import ndarray as nd
+
 from . import util
-from .. import ndarray as nd
 from ..api import register_func
 from .._ffi.base import py_str
 

python/tvm/datatype.py

@@ -20,7 +20,7 @@
 from . import make as _make
 from .api import convert
 from .expr import Call as _Call, Cast as _Cast, FloatImm as _FloatImm
-from ._ffi.runtime_ctypes import TVMType as _TVMType
+from ._ffi.runtime_ctypes import DataType
 from . import _api_internal
 
 
@@ -131,7 +131,7 @@ def lower(op):
         width as the custom type is returned. Otherwise, the type is
         unchanged."""
         dtype = op.dtype
-        t = _TVMType(dtype)
+        t = DataType(dtype)
         if get_type_registered(t.type_code):
             dtype = "uint" + str(t.bits)
             if t.lanes > 1:

python/tvm/expr.py

@@ -31,12 +31,9 @@
   assert(y.a == x)
 """
 # pylint: disable=missing-docstring
-from __future__ import absolute_import as _abs
 import tvm._ffi
+from tvm.runtime import Object, ObjectGeneric, DataType, TypeCode
 
-from ._ffi.object import Object
-from ._ffi.object_generic import ObjectGeneric
-from ._ffi.runtime_ctypes import TVMType, TypeCode
 from . import make as _make
 from . import generic as _generic
 from . import _api_internal
@@ -52,7 +49,7 @@ def _dtype_is_int(value):
     if isinstance(value, int):
         return True
     return (isinstance(value, ExprOp) and
-            TVMType(value.dtype).type_code == TypeCode.INT)
+            DataType(value.dtype).type_code == TypeCode.INT)
 
 
 class ExprOp(object):