#!/usr/bin/env python
# ******************************************************************************
# Copyright 2023 Brainchip Holdings Ltd.
#
# Licensed 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.
# ******************************************************************************
__all__ = ["QuantizedConv2D", "get_qconv"]
import numpy as np
from onnx import AttributeProto as AP, TensorProto as TP
from onnx.helper import make_node
from .base_layer import OnnxLayer
from .subgraph_ops import cast_tensors_to, get_pool_ops, get_scale_out_ops
from .subgraph_ops.activation import get_activation_ops
from .subgraph_ops.padding import get_padding_ops, transform_pads_into_array
from .compute_shapes import compute_onnx_conv_output
from .layer_compatibility import check_clip_relu_compatibility
from ..graph_tools import (TENSOR_SHAPE, get_field, get_node, get_variable, get_tensor_shape,
check_node_attributes)
from ..quantization.weights import quantize_weights, quantize_vector, fold_zero_point, align_to
from ..quantization.outputs import downscale
def get_qconv(nodes, graph):
conv_node = nodes[0]
assert conv_node.op_type == 'Conv'
# Check supported attributes
weights = get_variable(conv_node.input[1], graph)
valid_attr = {'auto_pad': ['NOTSET'], 'dilations': [[1] * (weights.ndim - 2)], 'group': [1]}
check_node_attributes(conv_node, valid_attr)
# Retrieve attributes
strides = get_field(conv_node, 'strides', (1, 1))
pool_type = "none"
pool_size = (2, 2)
pool_strides = (1, 1)
pool_node = get_node(nodes, 'MaxPool')
pool_pads = [0, 0, 0, 0]
if pool_node:
pool_type = "max"
# kernel_shape attribute is mandatory for MaxPool
pool_size = get_field(pool_node, 'kernel_shape')
pool_strides = get_field(pool_node, 'strides', pool_strides)
pool_pads = get_field(pool_node, "pads", pool_pads)
pool_node = get_node(nodes, 'GlobalAveragePool')
if pool_node:
pool_type = "gap"
act_node = get_node(nodes, 'Relu')
clip_node = get_node(nodes, 'Clip')
qconv = QuantizedConv2D(strides=strides,
pool_type=pool_type,
pool_size=pool_size,
pool_strides=pool_strides,
pool_pads=pool_pads,
activation=bool(act_node) or bool(clip_node),
name=conv_node.name)
# Sets the weights to configure the operation chain
qconv.set_weight("kernel", weights)
# If third attribute is there and it is not empty, then there is a bias
if len(conv_node.input) == 3 and conv_node.input[2]:
qconv.set_weight("bias", get_variable(conv_node.input[2], graph))
pads = get_field(conv_node, 'pads', False)
if pads:
qconv.set_weight("pads", transform_pads_into_array(pads))
if clip_node:
check_clip_relu_compatibility(clip_node, graph)
qconv.set_weight("max_value", get_variable(clip_node.input[2], graph))
return qconv
[docs]
class QuantizedConv2D(OnnxLayer):
"""Intermediate representation of QLinearConv() + MaxPool() + ReLU() as an exportable node.
Args:
strides (list of int, optional): the convolutional strides. Defaults to [1, 1].
pool_type (str, optional): the pool type, one of {"none", "max", "gap"}. Defaults to "none".
pool_size (list of int, optional): the kernel pool shape.
Ignore it when pool_type != "max". Defaults to (2, 2).
pool_stride (list of int, optional): the kernel strides.
Ignore it when pool_type != "max". Defaults to (2, 2).
pool_pads (list of int, optional): the size of each padding dimension.
Ignore it when pool_type != "max". Defaults to [0, 0, 0, 0].
input_conv (bool, optional): whether it is extended the set of operations of
the basic QuantizedConv2D, allowing to modify the padding value per input channel.
Defaults to False.
activation (bool, optional): whether to apply relu operation. Defaults to False.
name (str, optional): the node name. Defaults to ''.
"""
def __init__(self,
strides=[1, 1],
pool_type="none",
pool_size=(2, 2),
pool_strides=(2, 2),
pool_pads=[0, 0, 0, 0],
activation=False,
name=''):
assert pool_type in ["none", "max", "gap"]
super().__init__("QuantizedConv2D",
strides=strides,
pool_size=pool_size,
pool_strides=pool_strides,
pool_pads=pool_pads,
name=name)
# Save properties need to serialize operation name
self.serialize_attr["pool_type"] = pool_type
self.serialize_attr["activation"] = activation
self.serialize_attr["scale"] = True
# Declare weights
self._add_weight("kernel")
self._add_weight("bias")
self._add_weight("max_value")
self._add_weight("pads", dtype="int64")
def __build__(self, input_ts, downscale=True):
assert input_ts.dtype in (np.uint8, np.int8)
assert downscale, f"{self.name} ({self.base_name}) does not support 32bit output"
assert self.weights["kernel"].ndim == 4
# The chain of operations is modified by the type of input:
kernel_shape = self.weights["kernel"].shape
if input_ts.dtype == np.uint8:
self.base_name = "QuantizedInputConv2D"
if self.weights["bias"].size == 0:
# Bias is mandatory on this configuration
filters = kernel_shape[0]
self.set_weight("bias", np.zeros(filters, dtype="float32"))
# Initialize weights
if self.weights["pads"].size == 0:
self.set_weight("pads", np.zeros(len(kernel_shape) * 2, dtype="int64"))
# Compute output shape
conv_output_shape = compute_onnx_conv_output(self, input_ts.shape)
output_ts = TENSOR_SHAPE(conv_output_shape, np.dtype("int8"))
return output_ts
def __quantize__(self, qinput, out_tensor_range, force_fp=False):
i_scale = qinput.weights["scale"]
# Perform cross-layer equalization, i.e.: rescale weights with input scale.
# To do that first reshape i_scale to put it into axis = 1 and be capable of broadcasting.
assert i_scale.ndim <= 1
kernel = self.weights["kernel"]
kernel = kernel / align_to(i_scale, kernel.ndim, axis=1)
# Quantize and set weights
qweights, i_scale = quantize_weights(kernel)
# Prepare tensors list with unique names
conv_name = self.name
prefix = conv_name + "_"
weights_dict = {}
bias = self.weights["bias"]
if "InputConv" in self.op_type:
# If calibration was done per tensor, repeat zero point over each channel
zero_point = qinput.weights["zero_point"]
if zero_point.size == 1:
zero_point = np.repeat(zero_point, kernel.shape[1])
weights_dict[prefix + "Xpad"] = zero_point
# Fold zero point in bias
# Note: Dequantize kernel instead to use the float to reduce quantization error
kernel = qweights / align_to(i_scale, qweights.ndim, axis=0)
bias = fold_zero_point(bias, kernel, zero_point)
weights_dict[prefix + "Wi"] = qweights
if "Biased" in self.op_type:
qbias = quantize_vector(bias, i_scale)
weights_dict[prefix + "B"] = qbias
weights_dict[prefix + "pads"] = self.weights["pads"]
# Reshape i_scale to match with channel axis
i_scale = align_to(i_scale, qweights.ndim)
# Quantize max value when there is an activation
if "Clipped" in self.op_type:
qmax_value = quantize_vector(self.weights["max_value"], i_scale, signed=False)
weights_dict[prefix + "max_value"] = qmax_value
# Fold spatial dimension when GAP
if "GlobalAvgPool" in self.op_type:
input_shape = get_tensor_shape(self.input)
input_shape = compute_onnx_conv_output(self, input_shape, apply_pool=False)
i_scale *= input_shape[-2] * input_shape[-1]
# Now consider calibrated output range
scale, s_out, ocalib_scale = downscale(out_tensor_range, i_scale, force_fp=force_fp)
weights_dict.update({prefix + "M": scale.astype("uint8"), prefix + "S_out": s_out})
# Return quantized weights and ouput scale
return weights_dict, ocalib_scale
@staticmethod
def build_subgraph(op_type):
# Cast input, weights (and bias) into float.
t_names = ["X", "", "W", ""]
if "InputConv" in op_type:
t_names[1] = "x_pad_value"
if "Biased" in op_type:
t_names[-1] = "bias"
nodes, t_names = cast_tensors_to(t_names)
# Pad + convolution
nodes += get_padding_ops(t_names[0], "Xi", t_names[1])
conv_tensor_names = nodes[-1].output[:1] + t_names[2:]
nodes.append(make_node("Conv", inputs=conv_tensor_names, outputs=["Yi"]))
nodes[-1].attribute.append(AP(name="strides", ref_attr_name="strides", type=AP.INTS))
# Maxpool (optional)
if "MaxPool" in op_type:
# Replace previous output as maxpool input
nodes[-1].output.__setitem__(0, nodes[-1].op_type)
nodes += get_pool_ops(nodes[-1].output[0], "Yi", pool_op_type="MaxPool")
# Activation (optional)
if "ReLU" in op_type:
# Replace previous output as relu input
nodes[-1].output.__setitem__(0, nodes[-1].op_type)
nodes += get_activation_ops(nodes[-1].output[0], "Yi", "ReLUClipped" in op_type)
# AvgPool (optional)
if "GlobalAvgPool" in op_type:
# Replace previous output as maxpool input
nodes[-1].output.__setitem__(0, nodes[-1].op_type)
nodes += get_pool_ops(nodes[-1].output[0], "Yi", pool_op_type="GlobalAvgPool")
# Scale out (with saturation) in float domain
shift_nodes, shift_t_names = cast_tensors_to(["Scale", "Shift"])
nodes += shift_nodes
nodes += get_scale_out_ops("Yi", "Yscaled", *shift_t_names)
# Cast output to expect type
nodes.append(make_node("Cast", ["Yscaled"], ["Y"], to=TP.INT8))
return nodes