MeCo/zero-cost-nas/foresight/pruners/measures/snip.py
HamsterMimi 189df25fd3 upload
2023-05-04 13:09:03 +08:00

70 lines
2.3 KiB
Python

# Copyright 2021 Samsung Electronics Co., 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.
# =============================================================================
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
import copy
import types
from . import measure
from ..p_utils import get_layer_metric_array
def snip_forward_conv2d(self, x):
return F.conv2d(x, self.weight * self.weight_mask, self.bias,
self.stride, self.padding, self.dilation, self.groups)
def snip_forward_linear(self, x):
return F.linear(x, self.weight * self.weight_mask, self.bias)
@measure('snip', bn=True, mode='param')
def compute_snip_per_weight(net, inputs, targets, mode, loss_fn, split_data=1):
for layer in net.modules():
if isinstance(layer, nn.Conv2d) or isinstance(layer, nn.Linear):
layer.weight_mask = nn.Parameter(torch.ones_like(layer.weight))
layer.weight.requires_grad = False
# Override the forward methods:
if isinstance(layer, nn.Conv2d):
layer.forward = types.MethodType(snip_forward_conv2d, layer)
if isinstance(layer, nn.Linear):
layer.forward = types.MethodType(snip_forward_linear, layer)
# Compute gradients (but don't apply them)
net.zero_grad()
N = inputs.shape[0]
for sp in range(split_data):
st=sp*N//split_data
en=(sp+1)*N//split_data
outputs = net.forward(inputs[st:en])
loss = loss_fn(outputs, targets[st:en])
loss.backward()
# select the gradients that we want to use for search/prune
def snip(layer):
if layer.weight_mask.grad is not None:
return torch.abs(layer.weight_mask.grad)
else:
return torch.zeros_like(layer.weight)
grads_abs = get_layer_metric_array(net, snip, mode)
return grads_abs