[microNPU][2a] Add CascaderGraph for cascading analysis (#9469)

A CascaderGraph augments a TE graph with additional
information needed by the cascading algorithms. This
includes defining a strict ordering on the operators
as well as including all the Propagators needed to
do the affine analysis of cascades.

The CascaderGraph consists of two object types, Parts
and Tensors. A Part is an augmented operator which
includes the Propagators and a Tensor is similar to a
TE tensor but stores additional information like
compression ratio.

cmake/modules/contrib/EthosU.cmake

@@ -18,12 +18,15 @@
 if(USE_ETHOSU)
   tvm_file_glob(GLOB COMPILER_ETHOSU_SRCS
                 src/relay/backend/contrib/ethosu/*
-                src/contrib/ethosu/cascader/*)
+                src/contrib/ethosu/cascader/*
+                src/contrib/ethosu/cascader/parts/*)
   list(APPEND COMPILER_SRCS ${COMPILER_ETHOSU_SRCS})
 else()
   # Keeping just utils.cc because it has Object definitions
   # used by python side
   tvm_file_glob(GLOB COMPILER_ETHOSU_SRCS
-                src/relay/backend/contrib/ethosu/utils.cc)
+                src/relay/backend/contrib/ethosu/utils.cc
+                src/contrib/ethosu/cascader/*
+                src/contrib/ethosu/cascader/parts/*)
   list(APPEND COMPILER_SRCS ${COMPILER_ETHOSU_SRCS})
 endif(USE_ETHOSU)

python/tvm/contrib/ethosu/cascader/__init__.py

@@ -14,10 +14,12 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-"""The NPU cascading planner.
+"""The NPU cascader.
 
 This component performs inter-operator scheduling to optimize
 for both performance and memory usage on Arm(R) Ethos(TM)-U NPUs.
 """
 from .stripe_config import StripeConfig
 from .propagator import Propagator
+from .graph import PerformanceInfo, Tensor, Part, TESubgraph, CascaderGraph
+from .parts import InlinePart

python/tvm/contrib/ethosu/cascader/graph.py

@@ -0,0 +1,170 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""Graph objects to define compute graphs for the NPU cascader."""
+from typing import List
+from collections import namedtuple
+import tvm._ffi
+
+from tvm.runtime import Object
+
+from .stripe_config import StripeConfig
+from . import _ffi_api
+
+
+TESubgraph = namedtuple("TESubgraph", ["input_tensors", "output_tensor"])
+
+
+@tvm._ffi.register_object("contrib.ethosu.cascader.PerformanceInfo")
+class PerformanceInfo(Object):
+    """PerformanceInfo class"""
+
+    @property
+    def compute_cycles(self):
+        return self._compute_cycles
+
+    @property
+    def read_bytes(self):
+        return list(self._read_bytes)
+
+    @property
+    def write_bytes(self):
+        return self._write_bytes
+
+
+@tvm._ffi.register_object("contrib.ethosu.cascader.Tensor")
+class Tensor(Object):
+    """Tensor class"""
+
+    def __init__(self, shape, dtype, is_constant=False, compression_ratio=1):
+        self.__init_handle_by_constructor__(
+            _ffi_api.Tensor, shape, dtype, is_constant, compression_ratio
+        )
+
+    def add_producer(self, part):
+        _ffi_api.TensorAddProducer(self, part)
+
+    def add_consumer(self, part):
+        _ffi_api.TensorAddConsumer(self, part)
+
+    @property
+    def producers(self):
+        return list(self._producers)
+
+    @property
+    def consumers(self):
+        return list(self._consumers)
+
+    @property
+    def shape(self):
+        return list(self._shape)
+
+    @property
+    def dtype(self):
+        return self._dtype
+
+    @property
+    def is_constant(self):
+        return self._is_constant
+
+    @property
+    def compression_ratio(self):
+        return self._compression_ratio
+
+    @property
+    def size(self):
+        return self._size
+
+
+class Part(Object):
+    """Part base class"""
+
+    def set_input(self, index: int, tensor: Tensor):
+        _ffi_api.PartSetInput(self, index, tensor)
+
+    def set_output(self, tensor: Tensor):
+        _ffi_api.PartSetOutput(self, tensor)
+
+    def calculate_input_stripe_configs(
+        self, output_stripe_config: StripeConfig
+    ) -> List[StripeConfig]:
+        return list(_ffi_api.PartCalculateInputStripeConfigs(self, output_stripe_config))
+
+    def get_stripe_align_hint(self) -> List[int]:
+        return list(_ffi_api.PartGetStripeAlignHint(self))
+
+    def get_performance_info(
+        self, stripe_config: StripeConfig, is_rolling: bool
+    ) -> PerformanceInfo:
+        return _ffi_api.PartGetPerformanceInfo(self, stripe_config, is_rolling)
+
+    @property
+    def input_tensors(self):
+        return list(self._input_tensors)
+
+    @property
+    def output_tensor(self):
+        return self._output_tensor
+
+    @property
+    def propagators(self):
+        return list(self._propagators)
+
+    @property
+    def in_line(self):
+        return self._in_line
+
+    @property
+    def subgraph(self):
+        return TESubgraph(list(self._te_input_tensors), self._te_output_tensor)
+
+
+@tvm._ffi.register_object("contrib.ethosu.cascader.CascaderGraph")
+class CascaderGraph(Object):
+    """A class to describe a graph of Parts and Tensors used by the cascader.
+
+    This class describes a graph consisting of two object types: Tensors and Parts.
+    It defines a topological ordering on the graph such that each Part and Tensor has a
+    position in the ordering. This ordering is used by the Plan and Proposal generation
+    algorithms. It is also the ordering the Parts are expected to be executed in.
+
+    In addition to defining an ordering, the Parts and Tensors are also all given unique
+    IDs which they can be referred to by."""
+
+    def __init__(self, input_tensors: List[Tensor], output_tensors: List[Tensor]):
+        self.__init_handle_by_constructor__(_ffi_api.CascaderGraph, input_tensors, output_tensors)
+
+    def get_part_id(self, part: Part) -> int:
+        return _ffi_api.CascaderGraphGetPartID(self, part)
+
+    def get_tensor_id(self, tensor: Tensor) -> int:
+        return _ffi_api.CascaderGraphGetTensorID(self, tensor)
+
+    @property
+    def input_tensors(self):
+        return list(self._input_tensors)
+
+    @property
+    def output_tensors(self):
+        return list(self._output_tensors)
+
+    @property
+    def tensor_order(self):
+        return list(self._tensor_order)
+
+    @property
+    def part_order(self):
+        return list(self._part_order)

python/tvm/contrib/ethosu/cascader/parts.py

@@ -0,0 +1,40 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""Parts used by the NPU cascader."""
+from typing import List
+import tvm._ffi
+
+from .propagator import Propagator
+from .graph import Part, TESubgraph
+from . import _ffi_api
+
+
+@tvm._ffi.register_object("contrib.ethosu.cascader.InlinePart")
+class InlinePart(Part):
+    """InlinePart class"""
+
+    def __init__(
+        self,
+        te_subgraph: TESubgraph,
+        propagators: List[Propagator],
+    ):
+        self.__init_handle_by_constructor__(
+            _ffi_api.InlinePart,
+            te_subgraph.input_tensors,
+            te_subgraph.output_tensor,
+            propagators,
+        )

src/contrib/ethosu/cascader/common.h

@@ -27,6 +27,8 @@
 #include <tvm/ir/expr.h>
 #include <tvm/runtime/container/array.h>
 
+#include <functional>
+#include <numeric>
 #include <vector>
 
 namespace tvm {
@@ -50,6 +52,22 @@ inline Array<Integer> make_array(const std::vector<int>& vec) {
   return arr;
 }
 
+/*!
+ * \brief Make a tvm::Array<Integer> from a size_t vector.
+ * \param vec The size_t vector.
+ * \return The Integer Array.
+ * \note Array<Integer>(std::vector<size_t>) doesn't work as this implicit
+ * type conversion fails. This is why this helper is required.
+ */
+inline Array<Integer> make_array(const std::vector<size_t>& vec) {
+  Array<Integer> arr;
+  arr.resize(vec.size());
+  for (unsigned int i = 0; i < vec.size(); ++i) {
+    arr.Set(i, Integer(vec[i]));
+  }
+  return arr;
+}
+
 /*!
  * \brief Make a tvm::Array<FloatImm> from an float vector.
  * \param vec The float vector.
@@ -69,7 +87,7 @@ inline Array<FloatImm> make_array(const std::vector<float>& vec) {
  * \param arr The Array.
  * \return The vector.
  */
-template <class T, class tvm_T>
+template <typename T, typename tvm_T>
 inline std::vector<T> make_vector(const Array<tvm_T>& arr) {
   std::vector<T> vec(arr.size());
   for (unsigned int i = 0; i < arr.size(); ++i) {
@@ -103,6 +121,11 @@ inline std::size_t hash_vector(const std::vector<T>& vec) {
   return seed;
 }
 
+template <class T>
+inline T mul_reduce(const std::vector<T>& vec) {
+  return std::accumulate(vec.begin(), vec.end(), 1, std::multiplies<T>());
+}
+
 }  // namespace cascader
 }  // namespace ethosu
 }  // namespace contrib