303 lines
12 KiB
Python
303 lines
12 KiB
Python
#!/usr/bin/env python3
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# -*- coding:utf-8 -*-
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#############################################################
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# File: Involution.py
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# Created Date: Tuesday July 20th 2021
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# Author: Chen Xuanhong
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# Email: chenxuanhongzju@outlook.com
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# Last Modified: Friday, 11th February 2022 12:08:41 am
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# Modified By: Chen Xuanhong
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# Copyright (c) 2021 Shanghai Jiao Tong University
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#############################################################
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import torch
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import torch.nn as nn
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from torch.nn.modules.utils import _pair
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from torch.autograd import Function
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import cupy
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from string import Template
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from collections import namedtuple
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Stream = namedtuple('Stream', ['ptr'])
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def Dtype(t):
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if isinstance(t, torch.cuda.FloatTensor):
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return 'float'
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elif isinstance(t, torch.cuda.DoubleTensor):
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return 'double'
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@cupy._util.memoize(for_each_device=True)
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def load_kernel(kernel_name, code, **kwargs):
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code = Template(code).substitute(**kwargs)
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kernel_code = cupy.cuda.compile_with_cache(code)
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return kernel_code.get_function(kernel_name)
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CUDA_NUM_THREADS = 1024
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kernel_loop = '''
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#define CUDA_KERNEL_LOOP(i, n) \
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for (int i = blockIdx.x * blockDim.x + threadIdx.x; \
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i < (n); \
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i += blockDim.x * gridDim.x)
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'''
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def GET_BLOCKS(N):
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return (N + CUDA_NUM_THREADS - 1) // CUDA_NUM_THREADS
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_involution_kernel = kernel_loop + '''
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extern "C"
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__global__ void involution_forward_kernel(
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const ${Dtype}* bottom_data, const ${Dtype}* weight_data, ${Dtype}* top_data) {
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CUDA_KERNEL_LOOP(index, ${nthreads}) {
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const int n = index / ${channels} / ${top_height} / ${top_width};
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const int c = (index / ${top_height} / ${top_width}) % ${channels};
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const int h = (index / ${top_width}) % ${top_height};
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const int w = index % ${top_width};
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const int g = c / (${channels} / ${groups});
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${Dtype} value = 0;
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#pragma unroll
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for (int kh = 0; kh < ${kernel_h}; ++kh) {
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#pragma unroll
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for (int kw = 0; kw < ${kernel_w}; ++kw) {
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const int h_in = -${pad_h} + h * ${stride_h} + kh * ${dilation_h};
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const int w_in = -${pad_w} + w * ${stride_w} + kw * ${dilation_w};
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if ((h_in >= 0) && (h_in < ${bottom_height})
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&& (w_in >= 0) && (w_in < ${bottom_width})) {
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const int offset = ((n * ${channels} + c) * ${bottom_height} + h_in)
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* ${bottom_width} + w_in;
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const int offset_weight = ((((n * ${groups} + g) * ${kernel_h} + kh) * ${kernel_w} + kw) * ${top_height} + h)
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* ${top_width} + w;
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value += weight_data[offset_weight] * bottom_data[offset];
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}
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}
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}
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top_data[index] = value;
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}
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}
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'''
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_involution_kernel_backward_grad_input = kernel_loop + '''
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extern "C"
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__global__ void involution_backward_grad_input_kernel(
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const ${Dtype}* const top_diff, const ${Dtype}* const weight_data, ${Dtype}* const bottom_diff) {
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CUDA_KERNEL_LOOP(index, ${nthreads}) {
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const int n = index / ${channels} / ${bottom_height} / ${bottom_width};
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const int c = (index / ${bottom_height} / ${bottom_width}) % ${channels};
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const int h = (index / ${bottom_width}) % ${bottom_height};
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const int w = index % ${bottom_width};
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const int g = c / (${channels} / ${groups});
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${Dtype} value = 0;
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#pragma unroll
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for (int kh = 0; kh < ${kernel_h}; ++kh) {
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#pragma unroll
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for (int kw = 0; kw < ${kernel_w}; ++kw) {
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const int h_out_s = h + ${pad_h} - kh * ${dilation_h};
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const int w_out_s = w + ${pad_w} - kw * ${dilation_w};
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if (((h_out_s % ${stride_h}) == 0) && ((w_out_s % ${stride_w}) == 0)) {
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const int h_out = h_out_s / ${stride_h};
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const int w_out = w_out_s / ${stride_w};
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if ((h_out >= 0) && (h_out < ${top_height})
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&& (w_out >= 0) && (w_out < ${top_width})) {
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const int offset = ((n * ${channels} + c) * ${top_height} + h_out)
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* ${top_width} + w_out;
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const int offset_weight = ((((n * ${groups} + g) * ${kernel_h} + kh) * ${kernel_w} + kw) * ${top_height} + h_out)
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* ${top_width} + w_out;
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value += weight_data[offset_weight] * top_diff[offset];
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}
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}
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}
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}
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bottom_diff[index] = value;
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}
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}
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'''
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_involution_kernel_backward_grad_weight = kernel_loop + '''
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extern "C"
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__global__ void involution_backward_grad_weight_kernel(
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const ${Dtype}* const top_diff, const ${Dtype}* const bottom_data, ${Dtype}* const buffer_data) {
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CUDA_KERNEL_LOOP(index, ${nthreads}) {
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const int h = (index / ${top_width}) % ${top_height};
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const int w = index % ${top_width};
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const int kh = (index / ${kernel_w} / ${top_height} / ${top_width})
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% ${kernel_h};
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const int kw = (index / ${top_height} / ${top_width}) % ${kernel_w};
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const int h_in = -${pad_h} + h * ${stride_h} + kh * ${dilation_h};
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const int w_in = -${pad_w} + w * ${stride_w} + kw * ${dilation_w};
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if ((h_in >= 0) && (h_in < ${bottom_height})
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&& (w_in >= 0) && (w_in < ${bottom_width})) {
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const int g = (index / ${kernel_h} / ${kernel_w} / ${top_height} / ${top_width}) % ${groups};
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const int n = (index / ${groups} / ${kernel_h} / ${kernel_w} / ${top_height} / ${top_width}) % ${num};
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${Dtype} value = 0;
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#pragma unroll
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for (int c = g * (${channels} / ${groups}); c < (g + 1) * (${channels} / ${groups}); ++c) {
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const int top_offset = ((n * ${channels} + c) * ${top_height} + h)
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* ${top_width} + w;
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const int bottom_offset = ((n * ${channels} + c) * ${bottom_height} + h_in)
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* ${bottom_width} + w_in;
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value += top_diff[top_offset] * bottom_data[bottom_offset];
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}
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buffer_data[index] = value;
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} else {
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buffer_data[index] = 0;
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}
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}
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}
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'''
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class _involution(Function):
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@staticmethod
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def forward(ctx, input, weight, stride, padding, dilation):
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assert input.dim() == 4 and input.is_cuda
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assert weight.dim() == 6 and weight.is_cuda
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batch_size, channels, height, width = input.size()
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kernel_h, kernel_w = weight.size()[2:4]
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output_h = int((height + 2 * padding[0] - (dilation[0] * (kernel_h - 1) + 1)) / stride[0] + 1)
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output_w = int((width + 2 * padding[1] - (dilation[1] * (kernel_w - 1) + 1)) / stride[1] + 1)
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output = input.new(batch_size, channels, output_h, output_w)
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n = output.numel()
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with torch.cuda.device_of(input):
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f = load_kernel('involution_forward_kernel', _involution_kernel, Dtype=Dtype(input), nthreads=n,
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num=batch_size, channels=channels, groups=weight.size()[1],
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bottom_height=height, bottom_width=width,
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top_height=output_h, top_width=output_w,
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kernel_h=kernel_h, kernel_w=kernel_w,
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stride_h=stride[0], stride_w=stride[1],
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dilation_h=dilation[0], dilation_w=dilation[1],
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pad_h=padding[0], pad_w=padding[1])
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f(block=(CUDA_NUM_THREADS,1,1),
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grid=(GET_BLOCKS(n),1,1),
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args=[input.data_ptr(), weight.data_ptr(), output.data_ptr()],
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stream=Stream(ptr=torch.cuda.current_stream().cuda_stream))
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ctx.save_for_backward(input, weight)
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ctx.stride, ctx.padding, ctx.dilation = stride, padding, dilation
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return output
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@staticmethod
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def backward(ctx, grad_output):
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assert grad_output.is_cuda and grad_output.is_contiguous()
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input, weight = ctx.saved_tensors
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stride, padding, dilation = ctx.stride, ctx.padding, ctx.dilation
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batch_size, channels, height, width = input.size()
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kernel_h, kernel_w = weight.size()[2:4]
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output_h, output_w = grad_output.size()[2:]
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grad_input, grad_weight = None, None
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opt = dict(Dtype=Dtype(grad_output),
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num=batch_size, channels=channels, groups=weight.size()[1],
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bottom_height=height, bottom_width=width,
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top_height=output_h, top_width=output_w,
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kernel_h=kernel_h, kernel_w=kernel_w,
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stride_h=stride[0], stride_w=stride[1],
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dilation_h=dilation[0], dilation_w=dilation[1],
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pad_h=padding[0], pad_w=padding[1])
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with torch.cuda.device_of(input):
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if ctx.needs_input_grad[0]:
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grad_input = input.new(input.size())
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n = grad_input.numel()
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opt['nthreads'] = n
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f = load_kernel('involution_backward_grad_input_kernel',
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_involution_kernel_backward_grad_input, **opt)
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f(block=(CUDA_NUM_THREADS,1,1),
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grid=(GET_BLOCKS(n),1,1),
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args=[grad_output.data_ptr(), weight.data_ptr(), grad_input.data_ptr()],
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stream=Stream(ptr=torch.cuda.current_stream().cuda_stream))
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if ctx.needs_input_grad[1]:
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grad_weight = weight.new(weight.size())
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n = grad_weight.numel()
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opt['nthreads'] = n
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f = load_kernel('involution_backward_grad_weight_kernel',
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_involution_kernel_backward_grad_weight, **opt)
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f(block=(CUDA_NUM_THREADS,1,1),
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grid=(GET_BLOCKS(n),1,1),
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args=[grad_output.data_ptr(), input.data_ptr(), grad_weight.data_ptr()],
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stream=Stream(ptr=torch.cuda.current_stream().cuda_stream))
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return grad_input, grad_weight, None, None, None
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def _involution_cuda(input, weight, bias=None, stride=1, padding=0, dilation=1):
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""" involution kernel
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"""
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assert input.size(0) == weight.size(0)
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assert input.size(-2)//stride == weight.size(-2)
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assert input.size(-1)//stride == weight.size(-1)
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if input.is_cuda:
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out = _involution.apply(input, weight, _pair(stride), _pair(padding), _pair(dilation))
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if bias is not None:
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out += bias.view(1,-1,1,1)
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else:
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raise NotImplementedError
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return out
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class involution(nn.Module):
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def __init__(self,
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channels,
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kernel_size,
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stride):
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super(involution, self).__init__()
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self.kernel_size = kernel_size
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self.stride = stride
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self.channels = channels
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reduction_ratio = 4
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self.group_channels = 8
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self.groups = self.channels // self.group_channels
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self.seblock = nn.Sequential(
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nn.Conv2d(in_channels = channels, out_channels = channels // reduction_ratio, kernel_size= 1),
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# nn.BatchNorm2d(channels // reduction_ratio),
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nn.ReLU(),
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nn.Conv2d(in_channels = channels // reduction_ratio, out_channels = kernel_size**2 * self.groups, kernel_size= 1)
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)
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# self.conv1 = ConvModule(
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# in_channels=channels,
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# out_channels=channels // reduction_ratio,
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# kernel_size=1,
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# conv_cfg=None,
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# norm_cfg=dict(type='BN'),
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# act_cfg=dict(type='ReLU'))
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# self.conv2 = ConvModule(
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# in_channels=channels // reduction_ratio,
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# out_channels=kernel_size**2 * self.groups,
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# kernel_size=1,
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# stride=1,
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# conv_cfg=None,
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# norm_cfg=None,
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# act_cfg=None)
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if stride > 1:
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self.avgpool = nn.AvgPool2d(stride, stride)
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def forward(self, x):
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# weight = self.conv2(self.conv1(x if self.stride == 1 else self.avgpool(x)))
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weight = self.seblock(x)
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b, c, h, w = weight.shape
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weight = weight.view(b, self.groups, self.kernel_size, self.kernel_size, h, w)
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out = _involution_cuda(x, weight, stride=self.stride, padding=(self.kernel_size-1)//2)
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return out
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