autodl-projects/xautodl/models/shape_searchs/SearchCifarResNet.py
2021-05-18 14:08:00 +00:00

761 lines
29 KiB
Python

##################################################
# Copyright (c) Xuanyi Dong [GitHub D-X-Y], 2019 #
##################################################
import math, torch
from collections import OrderedDict
from bisect import bisect_right
import torch.nn as nn
from ..initialization import initialize_resnet
from ..SharedUtils import additive_func
from .SoftSelect import select2withP, ChannelWiseInter
from .SoftSelect import linear_forward
from .SoftSelect import get_width_choices
def get_depth_choices(nDepth, return_num):
if nDepth == 2:
choices = (1, 2)
elif nDepth == 3:
choices = (1, 2, 3)
elif nDepth > 3:
choices = list(range(1, nDepth + 1, 2))
if choices[-1] < nDepth:
choices.append(nDepth)
else:
raise ValueError("invalid nDepth : {:}".format(nDepth))
if return_num:
return len(choices)
else:
return choices
def conv_forward(inputs, conv, choices):
iC = conv.in_channels
fill_size = list(inputs.size())
fill_size[1] = iC - fill_size[1]
filled = torch.zeros(fill_size, device=inputs.device)
xinputs = torch.cat((inputs, filled), dim=1)
outputs = conv(xinputs)
selecteds = [outputs[:, :oC] for oC in choices]
return selecteds
class ConvBNReLU(nn.Module):
num_conv = 1
def __init__(
self, nIn, nOut, kernel, stride, padding, bias, has_avg, has_bn, has_relu
):
super(ConvBNReLU, self).__init__()
self.InShape = None
self.OutShape = None
self.choices = get_width_choices(nOut)
self.register_buffer("choices_tensor", torch.Tensor(self.choices))
if has_avg:
self.avg = nn.AvgPool2d(kernel_size=2, stride=2, padding=0)
else:
self.avg = None
self.conv = nn.Conv2d(
nIn,
nOut,
kernel_size=kernel,
stride=stride,
padding=padding,
dilation=1,
groups=1,
bias=bias,
)
# if has_bn : self.bn = nn.BatchNorm2d(nOut)
# else : self.bn = None
self.has_bn = has_bn
self.BNs = nn.ModuleList()
for i, _out in enumerate(self.choices):
self.BNs.append(nn.BatchNorm2d(_out))
if has_relu:
self.relu = nn.ReLU(inplace=True)
else:
self.relu = None
self.in_dim = nIn
self.out_dim = nOut
self.search_mode = "basic"
def get_flops(self, channels, check_range=True, divide=1):
iC, oC = channels
if check_range:
assert (
iC <= self.conv.in_channels and oC <= self.conv.out_channels
), "{:} vs {:} | {:} vs {:}".format(
iC, self.conv.in_channels, oC, self.conv.out_channels
)
assert (
isinstance(self.InShape, tuple) and len(self.InShape) == 2
), "invalid in-shape : {:}".format(self.InShape)
assert (
isinstance(self.OutShape, tuple) and len(self.OutShape) == 2
), "invalid out-shape : {:}".format(self.OutShape)
# conv_per_position_flops = self.conv.kernel_size[0] * self.conv.kernel_size[1] * iC * oC / self.conv.groups
conv_per_position_flops = (
self.conv.kernel_size[0] * self.conv.kernel_size[1] * 1.0 / self.conv.groups
)
all_positions = self.OutShape[0] * self.OutShape[1]
flops = (conv_per_position_flops * all_positions / divide) * iC * oC
if self.conv.bias is not None:
flops += all_positions / divide
return flops
def get_range(self):
return [self.choices]
def forward(self, inputs):
if self.search_mode == "basic":
return self.basic_forward(inputs)
elif self.search_mode == "search":
return self.search_forward(inputs)
else:
raise ValueError("invalid search_mode = {:}".format(self.search_mode))
def search_forward(self, tuple_inputs):
assert (
isinstance(tuple_inputs, tuple) and len(tuple_inputs) == 5
), "invalid type input : {:}".format(type(tuple_inputs))
inputs, expected_inC, probability, index, prob = tuple_inputs
index, prob = torch.squeeze(index).tolist(), torch.squeeze(prob)
probability = torch.squeeze(probability)
assert len(index) == 2, "invalid length : {:}".format(index)
# compute expected flop
# coordinates = torch.arange(self.x_range[0], self.x_range[1]+1).type_as(probability)
expected_outC = (self.choices_tensor * probability).sum()
expected_flop = self.get_flops([expected_inC, expected_outC], False, 1e6)
if self.avg:
out = self.avg(inputs)
else:
out = inputs
# convolutional layer
out_convs = conv_forward(out, self.conv, [self.choices[i] for i in index])
out_bns = [self.BNs[idx](out_conv) for idx, out_conv in zip(index, out_convs)]
# merge
out_channel = max([x.size(1) for x in out_bns])
outA = ChannelWiseInter(out_bns[0], out_channel)
outB = ChannelWiseInter(out_bns[1], out_channel)
out = outA * prob[0] + outB * prob[1]
# out = additive_func(out_bns[0]*prob[0], out_bns[1]*prob[1])
if self.relu:
out = self.relu(out)
else:
out = out
return out, expected_outC, expected_flop
def basic_forward(self, inputs):
if self.avg:
out = self.avg(inputs)
else:
out = inputs
conv = self.conv(out)
if self.has_bn:
out = self.BNs[-1](conv)
else:
out = conv
if self.relu:
out = self.relu(out)
else:
out = out
if self.InShape is None:
self.InShape = (inputs.size(-2), inputs.size(-1))
self.OutShape = (out.size(-2), out.size(-1))
return out
class ResNetBasicblock(nn.Module):
expansion = 1
num_conv = 2
def __init__(self, inplanes, planes, stride):
super(ResNetBasicblock, self).__init__()
assert stride == 1 or stride == 2, "invalid stride {:}".format(stride)
self.conv_a = ConvBNReLU(
inplanes,
planes,
3,
stride,
1,
False,
has_avg=False,
has_bn=True,
has_relu=True,
)
self.conv_b = ConvBNReLU(
planes, planes, 3, 1, 1, False, has_avg=False, has_bn=True, has_relu=False
)
if stride == 2:
self.downsample = ConvBNReLU(
inplanes,
planes,
1,
1,
0,
False,
has_avg=True,
has_bn=False,
has_relu=False,
)
elif inplanes != planes:
self.downsample = ConvBNReLU(
inplanes,
planes,
1,
1,
0,
False,
has_avg=False,
has_bn=True,
has_relu=False,
)
else:
self.downsample = None
self.out_dim = planes
self.search_mode = "basic"
def get_range(self):
return self.conv_a.get_range() + self.conv_b.get_range()
def get_flops(self, channels):
assert len(channels) == 3, "invalid channels : {:}".format(channels)
flop_A = self.conv_a.get_flops([channels[0], channels[1]])
flop_B = self.conv_b.get_flops([channels[1], channels[2]])
if hasattr(self.downsample, "get_flops"):
flop_C = self.downsample.get_flops([channels[0], channels[-1]])
else:
flop_C = 0
if (
channels[0] != channels[-1] and self.downsample is None
): # this short-cut will be added during the infer-train
flop_C = (
channels[0]
* channels[-1]
* self.conv_b.OutShape[0]
* self.conv_b.OutShape[1]
)
return flop_A + flop_B + flop_C
def forward(self, inputs):
if self.search_mode == "basic":
return self.basic_forward(inputs)
elif self.search_mode == "search":
return self.search_forward(inputs)
else:
raise ValueError("invalid search_mode = {:}".format(self.search_mode))
def search_forward(self, tuple_inputs):
assert (
isinstance(tuple_inputs, tuple) and len(tuple_inputs) == 5
), "invalid type input : {:}".format(type(tuple_inputs))
inputs, expected_inC, probability, indexes, probs = tuple_inputs
assert indexes.size(0) == 2 and probs.size(0) == 2 and probability.size(0) == 2
out_a, expected_inC_a, expected_flop_a = self.conv_a(
(inputs, expected_inC, probability[0], indexes[0], probs[0])
)
out_b, expected_inC_b, expected_flop_b = self.conv_b(
(out_a, expected_inC_a, probability[1], indexes[1], probs[1])
)
if self.downsample is not None:
residual, _, expected_flop_c = self.downsample(
(inputs, expected_inC, probability[1], indexes[1], probs[1])
)
else:
residual, expected_flop_c = inputs, 0
out = additive_func(residual, out_b)
return (
nn.functional.relu(out, inplace=True),
expected_inC_b,
sum([expected_flop_a, expected_flop_b, expected_flop_c]),
)
def basic_forward(self, inputs):
basicblock = self.conv_a(inputs)
basicblock = self.conv_b(basicblock)
if self.downsample is not None:
residual = self.downsample(inputs)
else:
residual = inputs
out = additive_func(residual, basicblock)
return nn.functional.relu(out, inplace=True)
class ResNetBottleneck(nn.Module):
expansion = 4
num_conv = 3
def __init__(self, inplanes, planes, stride):
super(ResNetBottleneck, self).__init__()
assert stride == 1 or stride == 2, "invalid stride {:}".format(stride)
self.conv_1x1 = ConvBNReLU(
inplanes, planes, 1, 1, 0, False, has_avg=False, has_bn=True, has_relu=True
)
self.conv_3x3 = ConvBNReLU(
planes,
planes,
3,
stride,
1,
False,
has_avg=False,
has_bn=True,
has_relu=True,
)
self.conv_1x4 = ConvBNReLU(
planes,
planes * self.expansion,
1,
1,
0,
False,
has_avg=False,
has_bn=True,
has_relu=False,
)
if stride == 2:
self.downsample = ConvBNReLU(
inplanes,
planes * self.expansion,
1,
1,
0,
False,
has_avg=True,
has_bn=False,
has_relu=False,
)
elif inplanes != planes * self.expansion:
self.downsample = ConvBNReLU(
inplanes,
planes * self.expansion,
1,
1,
0,
False,
has_avg=False,
has_bn=True,
has_relu=False,
)
else:
self.downsample = None
self.out_dim = planes * self.expansion
self.search_mode = "basic"
def get_range(self):
return (
self.conv_1x1.get_range()
+ self.conv_3x3.get_range()
+ self.conv_1x4.get_range()
)
def get_flops(self, channels):
assert len(channels) == 4, "invalid channels : {:}".format(channels)
flop_A = self.conv_1x1.get_flops([channels[0], channels[1]])
flop_B = self.conv_3x3.get_flops([channels[1], channels[2]])
flop_C = self.conv_1x4.get_flops([channels[2], channels[3]])
if hasattr(self.downsample, "get_flops"):
flop_D = self.downsample.get_flops([channels[0], channels[-1]])
else:
flop_D = 0
if (
channels[0] != channels[-1] and self.downsample is None
): # this short-cut will be added during the infer-train
flop_D = (
channels[0]
* channels[-1]
* self.conv_1x4.OutShape[0]
* self.conv_1x4.OutShape[1]
)
return flop_A + flop_B + flop_C + flop_D
def forward(self, inputs):
if self.search_mode == "basic":
return self.basic_forward(inputs)
elif self.search_mode == "search":
return self.search_forward(inputs)
else:
raise ValueError("invalid search_mode = {:}".format(self.search_mode))
def basic_forward(self, inputs):
bottleneck = self.conv_1x1(inputs)
bottleneck = self.conv_3x3(bottleneck)
bottleneck = self.conv_1x4(bottleneck)
if self.downsample is not None:
residual = self.downsample(inputs)
else:
residual = inputs
out = additive_func(residual, bottleneck)
return nn.functional.relu(out, inplace=True)
def search_forward(self, tuple_inputs):
assert (
isinstance(tuple_inputs, tuple) and len(tuple_inputs) == 5
), "invalid type input : {:}".format(type(tuple_inputs))
inputs, expected_inC, probability, indexes, probs = tuple_inputs
assert indexes.size(0) == 3 and probs.size(0) == 3 and probability.size(0) == 3
out_1x1, expected_inC_1x1, expected_flop_1x1 = self.conv_1x1(
(inputs, expected_inC, probability[0], indexes[0], probs[0])
)
out_3x3, expected_inC_3x3, expected_flop_3x3 = self.conv_3x3(
(out_1x1, expected_inC_1x1, probability[1], indexes[1], probs[1])
)
out_1x4, expected_inC_1x4, expected_flop_1x4 = self.conv_1x4(
(out_3x3, expected_inC_3x3, probability[2], indexes[2], probs[2])
)
if self.downsample is not None:
residual, _, expected_flop_c = self.downsample(
(inputs, expected_inC, probability[2], indexes[2], probs[2])
)
else:
residual, expected_flop_c = inputs, 0
out = additive_func(residual, out_1x4)
return (
nn.functional.relu(out, inplace=True),
expected_inC_1x4,
sum(
[
expected_flop_1x1,
expected_flop_3x3,
expected_flop_1x4,
expected_flop_c,
]
),
)
class SearchShapeCifarResNet(nn.Module):
def __init__(self, block_name, depth, num_classes):
super(SearchShapeCifarResNet, self).__init__()
# Model type specifies number of layers for CIFAR-10 and CIFAR-100 model
if block_name == "ResNetBasicblock":
block = ResNetBasicblock
assert (depth - 2) % 6 == 0, "depth should be one of 20, 32, 44, 56, 110"
layer_blocks = (depth - 2) // 6
elif block_name == "ResNetBottleneck":
block = ResNetBottleneck
assert (depth - 2) % 9 == 0, "depth should be one of 164"
layer_blocks = (depth - 2) // 9
else:
raise ValueError("invalid block : {:}".format(block_name))
self.message = (
"SearchShapeCifarResNet : Depth : {:} , Layers for each block : {:}".format(
depth, layer_blocks
)
)
self.num_classes = num_classes
self.channels = [16]
self.layers = nn.ModuleList(
[
ConvBNReLU(
3, 16, 3, 1, 1, False, has_avg=False, has_bn=True, has_relu=True
)
]
)
self.InShape = None
self.depth_info = OrderedDict()
self.depth_at_i = OrderedDict()
for stage in range(3):
cur_block_choices = get_depth_choices(layer_blocks, False)
assert (
cur_block_choices[-1] == layer_blocks
), "stage={:}, {:} vs {:}".format(stage, cur_block_choices, layer_blocks)
self.message += (
"\nstage={:} ::: depth-block-choices={:} for {:} blocks.".format(
stage, cur_block_choices, layer_blocks
)
)
block_choices, xstart = [], len(self.layers)
for iL in range(layer_blocks):
iC = self.channels[-1]
planes = 16 * (2 ** stage)
stride = 2 if stage > 0 and iL == 0 else 1
module = block(iC, planes, stride)
self.channels.append(module.out_dim)
self.layers.append(module)
self.message += "\nstage={:}, ilayer={:02d}/{:02d}, block={:03d}, iC={:3d}, oC={:3d}, stride={:}".format(
stage,
iL,
layer_blocks,
len(self.layers) - 1,
iC,
module.out_dim,
stride,
)
# added for depth
layer_index = len(self.layers) - 1
if iL + 1 in cur_block_choices:
block_choices.append(layer_index)
if iL + 1 == layer_blocks:
self.depth_info[layer_index] = {
"choices": block_choices,
"stage": stage,
"xstart": xstart,
}
self.depth_info_list = []
for xend, info in self.depth_info.items():
self.depth_info_list.append((xend, info))
xstart, xstage = info["xstart"], info["stage"]
for ilayer in range(xstart, xend + 1):
idx = bisect_right(info["choices"], ilayer - 1)
self.depth_at_i[ilayer] = (xstage, idx)
self.avgpool = nn.AvgPool2d(8)
self.classifier = nn.Linear(module.out_dim, num_classes)
self.InShape = None
self.tau = -1
self.search_mode = "basic"
# assert sum(x.num_conv for x in self.layers) + 1 == depth, 'invalid depth check {:} vs {:}'.format(sum(x.num_conv for x in self.layers)+1, depth)
# parameters for width
self.Ranges = []
self.layer2indexRange = []
for i, layer in enumerate(self.layers):
start_index = len(self.Ranges)
self.Ranges += layer.get_range()
self.layer2indexRange.append((start_index, len(self.Ranges)))
assert len(self.Ranges) + 1 == depth, "invalid depth check {:} vs {:}".format(
len(self.Ranges) + 1, depth
)
self.register_parameter(
"width_attentions",
nn.Parameter(torch.Tensor(len(self.Ranges), get_width_choices(None))),
)
self.register_parameter(
"depth_attentions",
nn.Parameter(torch.Tensor(3, get_depth_choices(layer_blocks, True))),
)
nn.init.normal_(self.width_attentions, 0, 0.01)
nn.init.normal_(self.depth_attentions, 0, 0.01)
self.apply(initialize_resnet)
def arch_parameters(self, LR=None):
if LR is None:
return [self.width_attentions, self.depth_attentions]
else:
return [
{"params": self.width_attentions, "lr": LR},
{"params": self.depth_attentions, "lr": LR},
]
def base_parameters(self):
return (
list(self.layers.parameters())
+ list(self.avgpool.parameters())
+ list(self.classifier.parameters())
)
def get_flop(self, mode, config_dict, extra_info):
if config_dict is not None:
config_dict = config_dict.copy()
# select channels
channels = [3]
for i, weight in enumerate(self.width_attentions):
if mode == "genotype":
with torch.no_grad():
probe = nn.functional.softmax(weight, dim=0)
C = self.Ranges[i][torch.argmax(probe).item()]
elif mode == "max":
C = self.Ranges[i][-1]
elif mode == "fix":
C = int(math.sqrt(extra_info) * self.Ranges[i][-1])
elif mode == "random":
assert isinstance(extra_info, float), "invalid extra_info : {:}".format(
extra_info
)
with torch.no_grad():
prob = nn.functional.softmax(weight, dim=0)
approximate_C = int(math.sqrt(extra_info) * self.Ranges[i][-1])
for j in range(prob.size(0)):
prob[j] = 1 / (
abs(j - (approximate_C - self.Ranges[i][j])) + 0.2
)
C = self.Ranges[i][torch.multinomial(prob, 1, False).item()]
else:
raise ValueError("invalid mode : {:}".format(mode))
channels.append(C)
# select depth
if mode == "genotype":
with torch.no_grad():
depth_probs = nn.functional.softmax(self.depth_attentions, dim=1)
choices = torch.argmax(depth_probs, dim=1).cpu().tolist()
elif mode == "max" or mode == "fix":
choices = [depth_probs.size(1) - 1 for _ in range(depth_probs.size(0))]
elif mode == "random":
with torch.no_grad():
depth_probs = nn.functional.softmax(self.depth_attentions, dim=1)
choices = torch.multinomial(depth_probs, 1, False).cpu().tolist()
else:
raise ValueError("invalid mode : {:}".format(mode))
selected_layers = []
for choice, xvalue in zip(choices, self.depth_info_list):
xtemp = xvalue[1]["choices"][choice] - xvalue[1]["xstart"] + 1
selected_layers.append(xtemp)
flop = 0
for i, layer in enumerate(self.layers):
s, e = self.layer2indexRange[i]
xchl = tuple(channels[s : e + 1])
if i in self.depth_at_i:
xstagei, xatti = self.depth_at_i[i]
if xatti <= choices[xstagei]: # leave this depth
flop += layer.get_flops(xchl)
else:
flop += 0 # do not use this layer
else:
flop += layer.get_flops(xchl)
# the last fc layer
flop += channels[-1] * self.classifier.out_features
if config_dict is None:
return flop / 1e6
else:
config_dict["xchannels"] = channels
config_dict["xblocks"] = selected_layers
config_dict["super_type"] = "infer-shape"
config_dict["estimated_FLOP"] = flop / 1e6
return flop / 1e6, config_dict
def get_arch_info(self):
string = (
"for depth and width, there are {:} + {:} attention probabilities.".format(
len(self.depth_attentions), len(self.width_attentions)
)
)
string += "\n{:}".format(self.depth_info)
discrepancy = []
with torch.no_grad():
for i, att in enumerate(self.depth_attentions):
prob = nn.functional.softmax(att, dim=0)
prob = prob.cpu()
selc = prob.argmax().item()
prob = prob.tolist()
prob = ["{:.3f}".format(x) for x in prob]
xstring = "{:03d}/{:03d}-th : {:}".format(
i, len(self.depth_attentions), " ".join(prob)
)
logt = ["{:.4f}".format(x) for x in att.cpu().tolist()]
xstring += " || {:17s}".format(" ".join(logt))
prob = sorted([float(x) for x in prob])
disc = prob[-1] - prob[-2]
xstring += " || discrepancy={:.2f} || select={:}/{:}".format(
disc, selc, len(prob)
)
discrepancy.append(disc)
string += "\n{:}".format(xstring)
string += "\n-----------------------------------------------"
for i, att in enumerate(self.width_attentions):
prob = nn.functional.softmax(att, dim=0)
prob = prob.cpu()
selc = prob.argmax().item()
prob = prob.tolist()
prob = ["{:.3f}".format(x) for x in prob]
xstring = "{:03d}/{:03d}-th : {:}".format(
i, len(self.width_attentions), " ".join(prob)
)
logt = ["{:.3f}".format(x) for x in att.cpu().tolist()]
xstring += " || {:52s}".format(" ".join(logt))
prob = sorted([float(x) for x in prob])
disc = prob[-1] - prob[-2]
xstring += " || dis={:.2f} || select={:}/{:}".format(
disc, selc, len(prob)
)
discrepancy.append(disc)
string += "\n{:}".format(xstring)
return string, discrepancy
def set_tau(self, tau_max, tau_min, epoch_ratio):
assert (
epoch_ratio >= 0 and epoch_ratio <= 1
), "invalid epoch-ratio : {:}".format(epoch_ratio)
tau = tau_min + (tau_max - tau_min) * (1 + math.cos(math.pi * epoch_ratio)) / 2
self.tau = tau
def get_message(self):
return self.message
def forward(self, inputs):
if self.search_mode == "basic":
return self.basic_forward(inputs)
elif self.search_mode == "search":
return self.search_forward(inputs)
else:
raise ValueError("invalid search_mode = {:}".format(self.search_mode))
def search_forward(self, inputs):
flop_width_probs = nn.functional.softmax(self.width_attentions, dim=1)
flop_depth_probs = nn.functional.softmax(self.depth_attentions, dim=1)
flop_depth_probs = torch.flip(
torch.cumsum(torch.flip(flop_depth_probs, [1]), 1), [1]
)
selected_widths, selected_width_probs = select2withP(
self.width_attentions, self.tau
)
selected_depth_probs = select2withP(self.depth_attentions, self.tau, True)
with torch.no_grad():
selected_widths = selected_widths.cpu()
x, last_channel_idx, expected_inC, flops = inputs, 0, 3, []
feature_maps = []
for i, layer in enumerate(self.layers):
selected_w_index = selected_widths[
last_channel_idx : last_channel_idx + layer.num_conv
]
selected_w_probs = selected_width_probs[
last_channel_idx : last_channel_idx + layer.num_conv
]
layer_prob = flop_width_probs[
last_channel_idx : last_channel_idx + layer.num_conv
]
x, expected_inC, expected_flop = layer(
(x, expected_inC, layer_prob, selected_w_index, selected_w_probs)
)
feature_maps.append(x)
last_channel_idx += layer.num_conv
if i in self.depth_info: # aggregate the information
choices = self.depth_info[i]["choices"]
xstagei = self.depth_info[i]["stage"]
# print ('iL={:}, choices={:}, stage={:}, probs={:}'.format(i, choices, xstagei, selected_depth_probs[xstagei].cpu().tolist()))
# for A, W in zip(choices, selected_depth_probs[xstagei]):
# print('Size = {:}, W = {:}'.format(feature_maps[A].size(), W))
possible_tensors = []
max_C = max(feature_maps[A].size(1) for A in choices)
for tempi, A in enumerate(choices):
xtensor = ChannelWiseInter(feature_maps[A], max_C)
# drop_ratio = 1-(tempi+1.0)/len(choices)
# xtensor = drop_path(xtensor, drop_ratio)
possible_tensors.append(xtensor)
weighted_sum = sum(
xtensor * W
for xtensor, W in zip(
possible_tensors, selected_depth_probs[xstagei]
)
)
x = weighted_sum
if i in self.depth_at_i:
xstagei, xatti = self.depth_at_i[i]
x_expected_flop = flop_depth_probs[xstagei, xatti] * expected_flop
else:
x_expected_flop = expected_flop
flops.append(x_expected_flop)
flops.append(expected_inC * (self.classifier.out_features * 1.0 / 1e6))
features = self.avgpool(x)
features = features.view(features.size(0), -1)
logits = linear_forward(features, self.classifier)
return logits, torch.stack([sum(flops)])
def basic_forward(self, inputs):
if self.InShape is None:
self.InShape = (inputs.size(-2), inputs.size(-1))
x = inputs
for i, layer in enumerate(self.layers):
x = layer(x)
features = self.avgpool(x)
features = features.view(features.size(0), -1)
logits = self.classifier(features)
return features, logits