When inputs are "nan"s, I expect outputs to be "nan"s as well. But I found that a nn.Conv2d layer, specifically with kernel_size = (3,3) and in GPU mode, outputs “-inf” instead of “nan”. Here are simple codes to verify.

```
import torch
import torch.nn as nn
x = torch.acos(1+torch.ones(1,1,3,3)) # Make a 'nan' tensor
model = nn.Conv2d(1,1,kernel_size=(3,3))
y = model(x)
print('input_cpu:',x)
print('output_cpu:',y)
model_gpu = model.cuda()
x_gpu = x.cuda()
y_gpu = model_gpu(x_gpu)
print('input_gpu:',x_gpu)
print('output_gpu:',y_gpu)
```

output:

```
input_cpu: tensor([[[[nan, nan, nan],
[nan, nan, nan],
[nan, nan, nan]]]])
output_cpu: tensor([[[[nan]]]], grad_fn=<ThnnConv2DBackward>)
input_gpu: tensor([[[[nan, nan, nan],
[nan, nan, nan],
[nan, nan, nan]]]], device='cuda:0')
output_gpu: tensor([[[[-inf]]]], device='cuda:0', grad_fn=<CudnnConvolutionBackward>)
```

Is this my problem only or you guys have the same issue?