IndexError when converting torch pad operator to TensorRT

[Thrsu]

Description

I encountered an issue while trying to convert the pad operator from torch to TensorRT. The following error message is displayed:

Traceback (most recent call last):
  File "test_4014.py", line 13, in <module>
    model_trt = torch2trt(model, [para_0])
  File "/home/henry/anaconda3/envs/tensorrt/lib/python3.8/site-packages/torch2trt-0.4.0-py3.8.egg/torch2trt/torch2trt.py", line 779, in torch2trt
    outputs = module(*inputs)
  File "/home/henry/anaconda3/envs/tensorrt/lib/python3.8/site-packages/torch/nn/modules/module.py", line 1128, in _call_impl
    result = forward_call(*input, **kwargs)
  File "test_4014.py", line 10, in forward
    return torch.nn.functional.pad(input, para_1,mode='circular',)
  File "/home/henry/anaconda3/envs/tensorrt/lib/python3.8/site-packages/torch2trt-0.4.0-py3.8.egg/torch2trt/torch2trt.py", line 310, in wrapper
    converter["converter"](ctx)
  File "/home/henry/anaconda3/envs/tensorrt/lib/python3.8/site-packages/torch2trt-0.4.0-py3.8.egg/torch2trt/converters/pad.py", line 12, in convert_pad
    pre_padding = (pad[2], pad[0])
IndexError: tuple index out of range

Reproduce

This bug can be reproduced by the below script:

from torch2trt import torch2trt
import torch
from torch.nn import Module

para_0 = torch.randn([2, 2, 4], dtype=torch.float32).cuda()
para_1 = (1, 1)
class pad(Module):
    def forward(self, input):
        return torch.nn.functional.pad(input, para_1,mode='circular',)

model = pad().float().cuda()
model_trt = torch2trt(model, [para_0])
y = model(para_0)
y_trt = model_trt(para_0)

# check the output against PyTorch
print(torch.max(torch.abs(y - y_trt)))

Environment

• torch: 1.11.0
• torch2trt: 0.4.0
• tensorrt: 8.6.1.6

[timegoby]

It's only support padding H,W at same time.
reference: https://github.com/NVIDIA-AI-IOT/torch2trt/blob/master/torch2trt/converters/pad.py#L17

[Thrsu]

Thank you for your response :)