from functools import reduce
import torch
import torch._utils
from ..function import Function
class Type(Function):
@staticmethod
def forward(ctx, i, dest_type):
ctx.input_type = type(i)
ctx.input_device = -1 if not i.is_cuda else i.get_device()
return i.type(dest_type)
@staticmethod
def backward(ctx, grad_output):
if ctx.input_device == -1:
return grad_output.type(ctx.input_type), None
else:
with torch.cuda.device(ctx.input_device):
return grad_output.type(ctx.input_type), None
# TODO: deprecate this
class Resize(Function):
@staticmethod
def forward(ctx, tensor, sizes):
ctx.sizes = sizes
ctx.numel = reduce(lambda x, y: x * y, sizes, 1)
if tensor.numel() != ctx.numel:
raise RuntimeError(("requested resize to {} ({} elements in total), "
"but the given tensor has a size of {} ({} elements). "
"autograd's resize can only change the shape of a given "
"tensor, while preserving the number of elements. ").format(
'x'.join(map(str, sizes)), ctx.numel,
'x'.join(map(str, tensor.size())), tensor.numel()))
ctx.input_sizes = tensor.size()
if tensor.is_quantized:
tensor.copy_(tensor)
return tensor.contiguous().view(*sizes)
if tensor.is_contiguous():
result = tensor.new(tensor).contiguous().view(*sizes)
return result
else:
return tensor.contiguous().view(*sizes)
@staticmethod
def backward(ctx, grad_output):
assert grad_output.numel() == ctx.numel
return grad_output.contiguous().view(ctx.input_sizes), None