pytorch/torch/quantization/quantize.py
Zafar Takhirov 1a74bd407d Fixes the adding of the observer to the FloatFunctional (#24418)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24418

Fixes #24394

The observer is not added correctlty, because one of the conditions is not met.

Test Plan: Imported from OSS

Differential Revision: D16833951

Pulled By: zafartahirov

fbshipit-source-id: bb4699e6a1cf6368c7278272a68e5e7c6d3f59a8
2019-08-15 17:27:00 -07:00

322 lines
11 KiB
Python

from __future__ import absolute_import, division, print_function, unicode_literals
import torch.nn as nn
import torch.nn._intrinsic as nni
import torch.nn._intrinsic.quantized as nniq
import torch.nn._intrinsic.qat as nniqat
import torch.nn.quantized as nnq
import torch.nn.quantized.dynamic as nnqd
from .QConfig import default_dynamic_qconfig
import torch.nn.qat as nnqat
DEFAULT_SKIP_LIST = [nn.Identity, nn.MaxPool2d]
def propagate_qconfig_helper(module, qconfig_dict, skip_list=DEFAULT_SKIP_LIST, qconfig_parent=None, prefix=''):
r"""This is a helper function for `propagate_qconfig`
Args:
module: input module
qconfig_dict: dictionary that maps from name of submodule to quantization
configuration
qconfig_parent: quantization config of parent module, we will fallback to
this config when there is no specified config for current
module
prefix: corresponding prefix of the current module, used as key in
qconfig_dict
Return:
None, module is modified inplace with qconfig attached
"""
if type(module) in skip_list:
module.qconfig = None
if not hasattr(module, 'qconfig'):
module.qconfig = qconfig_parent
if qconfig_dict:
if prefix in qconfig_dict:
module.qconfig = qconfig_dict[prefix]
elif type(module) in qconfig_dict:
module.qconfig = qconfig_dict[type(module)]
# Don't quantize empty Sequential, empty Sequential is same as
# Identity, but we can't put Sequential into skip list because
# we also have non-empty Sequential and the qconfig needs to
# be propagated to child in that case
# TODO: Add test
if len(module._modules) == 0 and type(module) == nn.Sequential:
module.qconfig = None
for name, child in module.named_children():
module_prefix = prefix + '.' + name if prefix else name
propagate_qconfig_helper(child, qconfig_dict, skip_list, module.qconfig, module_prefix)
# TODO(jerryzh): expose skip_list
def propagate_qconfig(module, qconfig_dict=None):
r"""Propagate qconfig through the module hierarchy and assign `qconfig`
attribute on each leaf module
Args:
module: input module
qconfig_dict: dictionary that maps from name of submodule to quantization
configuration, qconfig applies to all submodules of a given
module unless qconfig for the submodules are specified(when the
submodule already has qconfig attribute)
Return:
None, module is modified inplace with qconfig attached
"""
if qconfig_dict is None:
qconfig_dict = {}
propagate_qconfig_helper(module, qconfig_dict)
def _observer_forward_hook(self, input, output):
r"""Forward hook that calls observer on the output
"""
return self.observer(output)
def add_observer(module):
r"""Add observer for the leaf child of the module.
This function insert observer module to all leaf child module that
has a valid qconfig attribute.
Args:
module: input module with qconfig attributes for all the leaf modules
that we want to quantize
Return:
None, module is modified inplace with added observer modules and
forward_hooks
"""
for child in module.children():
if type(child) == nnq.FloatFunctional:
child.observer = child.qconfig.activation()
else:
add_observer(child)
# Insert observers only for leaf nodes, note that this observer is for
# the output of the module, for input QuantStub will observe them
if hasattr(module, 'qconfig') and module.qconfig is not None and \
len(module._modules) == 0:
# observer and hook will be gone after we swap the module
module.add_module('observer', module.qconfig.activation())
module.register_forward_hook(_observer_forward_hook)
class QuantWrapper(nn.Module):
r"""A wrapper class that wraps the input module, adds QuantStub and
DeQuantStub and surround the call to module with call to quant and dequant
modules.
This is used by the `quantization` utility functions to add the quant and
dequant modules, before `convert` function `QuantStub` will just be observer,
it observes the input tensor, after `convert`, `QuantStub`
will be swapped to `nnq.Quantize` which does actual quantization. Similarly
for `DeQuantStub`.
"""
def __init__(self, module):
super(QuantWrapper, self).__init__()
qconfig = module.qconfig if hasattr(module, 'qconfig') else None
self.add_module('quant', QuantStub(qconfig))
self.add_module('dequant', DeQuantStub(qconfig))
self.add_module('module', module)
self.train(module.training)
def forward(self, X):
X = self.quant(X)
X = self.module(X)
return self.dequant(X)
def add_quant_dequant(module):
r"""Wrap the leaf child module in QuantWrapper if it has a valid qconfig
Note that this function will modify the children of module inplace and it
can return a new module which wraps the input module as well.
Args:
module: input module with qconfig attributes for all the leaf modules
that we want to quantize
Return:
Either the inplace modified module with submodules wrapped in
`QuantWrapper` based on qconfig or a new `QuantWrapper` module which
wraps the input module, the latter case only happens when the input
module is a leaf module and we want to quantize it.
"""
if len(module._modules) == 0 and hasattr(module, 'qconfig') and module.qconfig:
return QuantWrapper(module)
for name, child in module.named_children():
module._modules[name] = add_quant_dequant(child)
return module
def prepare(model):
r"""Prepares the model for calibration or training.
Note that the model will be modified inplace but in case the input model
is a leaf model, a wrapped model will be returned.
Args:
mod: input model
Return:
A model with qconfig propogated, observer and quant dequant or fake
quant modules attached, a model that is ready for calibration or
training
"""
propagate_qconfig(model)
add_observer(model)
return model
class QuantStub(nn.Module):
r"""Quantize stub module, before calibration, this is same as an observer,
it will be swapped as `nnq.Quantize` in `convert`.
Args:
qconfig: quantization configuration for the tensor,
if qconfig is not provided, we will get qconfig from parent modules
"""
def __init__(self, qconfig=None):
super(QuantStub, self).__init__()
if qconfig:
self.qconfig = qconfig
def forward(self, x):
return x
class DeQuantStub(nn.Module):
r"""Dequantize stub module, before calibration, this is same as identity,
this will be swapped as `nnq.DeQuantize` in `convert`.
"""
def __init__(self, qconfig=None):
super(DeQuantStub, self).__init__()
if qconfig:
self.qconfig = qconfig
def forward(self, x):
return x
# Map for swapping float module to quantized ones
DEFAULT_MODULE_MAPPING = {
nn.Linear: nnq.Linear,
nn.ReLU: nnq.ReLU,
nn.Conv2d: nnq.Conv2d,
QuantStub: nnq.Quantize,
DeQuantStub: nnq.DeQuantize,
# Intrinsic modules:
nni.ConvReLU2d: nniq.ConvReLU2d,
nni.LinearReLU: nniq.LinearReLU,
nniqat.ConvReLU2d: nniq.ConvReLU2d,
nniqat.LinearReLU: nniq.LinearReLU,
nniqat.ConvBn2d: nnq.Conv2d,
nniqat.ConvBnReLU2d: nniq.ConvReLU2d,
# QAT modules:
nnqat.Linear: nnq.Linear,
nnqat.Conv2d: nnq.Conv2d,
}
# Map for swapping float module to qat modules
DEFAULT_QAT_MODULE_MAPPING = {
nn.Linear: nnqat.Linear,
nn.Conv2d: nnqat.Conv2d,
# Intrinsic modules:
nni.ConvBn2d: nniqat.ConvBn2d,
nni.ConvBnReLU2d: nniqat.ConvBnReLU2d,
nni.ConvReLU2d: nniqat.ConvReLU2d,
nni.LinearReLU: nniqat.LinearReLU
}
DEFAULT_DYNAMIC_MODULE_MAPPING = {
nn.Linear: nnqd.Linear
}
def quantize(model, run_fn, run_args, mapping=DEFAULT_MODULE_MAPPING):
r"""Converts a float model to quantized model.
First it will prepare the model for calibration or training, then it calls
`run_fn` which will run the calibration step or training step,
after that we will call `convert` which will convert the model to a
quantized model.
Args:
model: input model
run_fn: a function for evaluating the prepared model, can be a
function that simply runs the prepared model or a training loop
run_args: positional arguments for `run_fn`
Return:
A quantized model
"""
model.eval()
model = prepare(model)
run_fn(model, run_args)
convert(model, mapping)
return model
DEFAULT_QCONFIG_DICT = {
nn.Linear : default_dynamic_qconfig
}
def quantize_dynamic(model, qconfig_dict=DEFAULT_QCONFIG_DICT, mapping=DEFAULT_DYNAMIC_MODULE_MAPPING):
r"""Converts a float model to dynamic quantized model. Do dynamic training and output a quantized model.
"""
model.eval()
propagate_qconfig(model, qconfig_dict)
convert(model, mapping)
return model
def prepare_qat(model):
model = prepare(model)
model = convert(model, DEFAULT_QAT_MODULE_MAPPING)
return model
def quantize_qat(model, run_fn, run_args):
r"""Do quantization aware training and output a quantized model
"""
model.train()
model = prepare_qat(model)
run_fn(model, run_args)
convert(model)
return model
def convert(module, mapping=DEFAULT_MODULE_MAPPING):
r"""Converts the float module with observers(where we can get quantization
parameters) to a quantized module.
Args:
module: calibrated module with observers
mapping: a dictionary that maps from float module type to quantized
module type, can be overwrritten to allow swapping user defined Modules
Return:
A quantized module
"""
module_swapped = swap_module(module, mapping)
reassign = {}
# TODO(jerryzh): remove after deciding on the impl of
# intrinsic moudles
if type(module) in [nni.ConvBn2d, nni.ConvBnReLU2d, nni.LinearReLU, nni.ConvReLU2d]:
return module_swapped
for name, mod in module.named_children():
new_mod = convert(mod, mapping)
if new_mod is not mod:
reassign[name] = new_mod
for name, mod in reassign.items():
setattr(module_swapped, name, mod)
return module_swapped
def swap_module(mod, mapping):
r"""Swaps the module if it has a quantized counterpart and it has an
`observer` attached.
Args:
mod: input module
mapping: a dictionary that maps from nn module to nnq module
Return:
The corresponding quantized module of `mod`
"""
new_mod = mod
if hasattr(mod, 'qconfig') and mod.qconfig is not None:
if type(mod) in mapping:
new_mod = mapping[type(mod)].from_float(mod)
return new_mod