pytorch/test/onnx/autograd_helper.py

# Owner(s): ["module: onnx"]

import torch


# Autograd function that is a replica of the autograd function in
# test_utility_funs.py (test_autograd_module_name)
class CustomFunction(torch.autograd.Function):
    @staticmethod
    def forward(ctx, input):
        ctx.save_for_backward(input)
        return input.clamp(min=0)

    @staticmethod
    def backward(ctx, grad_output):
        (input,) = ctx.saved_tensors
        grad_input = grad_output.clone()
        grad_input[input < 0] = 0
        return grad_input