Given the same model, I found that the calculated flops in pytorch and tensorflow are different. I used the keras_flops (keras-flops · PyPI) in tensorflow, and ptflops (ptflops · PyPI) in pytorch to calculate flops. Is that TensorFlow has some tricks to speed up the computation so that few flops are measured? How come pytorch and tensorflow can have different flops with the same model?

The FLops in pytorch is

```
Model_1(
0.013 M, 100.000% Params, 45.486 GMac, 100.000% MACs,
(begin): Sequential(
0.002 M, 11.804% Params, 0.851 GMac, 1.870% MACs,
(0): Conv2d(0.001 M, 11.367% Params, 0.819 GMac, 1.801% MACs, 1, 56, kernel_size=(5, 5), stride=(1, 1), padding=(2, 2))
(1): PReLU(0.0 M, 0.437% Params, 0.032 GMac, 0.069% MACs, num_parameters=56)
)
(middle): Sequential(
0.007 M, 52.775% Params, 3.803 GMac, 8.360% MACs,
(0): Conv2d(0.001 M, 5.340% Params, 0.385 GMac, 0.846% MACs, 56, 12, kernel_size=(1, 1), stride=(1, 1))
(1): PReLU(0.0 M, 0.094% Params, 0.007 GMac, 0.015% MACs, num_parameters=12)
(2): Conv2d(0.001 M, 10.212% Params, 0.736 GMac, 1.618% MACs, 12, 12, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
(3): PReLU(0.0 M, 0.094% Params, 0.007 GMac, 0.015% MACs, num_parameters=12)
(4): Conv2d(0.001 M, 10.212% Params, 0.736 GMac, 1.618% MACs, 12, 12, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
(5): PReLU(0.0 M, 0.094% Params, 0.007 GMac, 0.015% MACs, num_parameters=12)
(6): Conv2d(0.001 M, 10.212% Params, 0.736 GMac, 1.618% MACs, 12, 12, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
(7): PReLU(0.0 M, 0.094% Params, 0.007 GMac, 0.015% MACs, num_parameters=12)
(8): Conv2d(0.001 M, 10.212% Params, 0.736 GMac, 1.618% MACs, 12, 12, kernel_size=(3, 3), stride=(1, 1), padding=(1, 1))
(9): PReLU(0.0 M, 0.094% Params, 0.007 GMac, 0.015% MACs, num_parameters=12)
(10): Conv2d(0.001 M, 5.684% Params, 0.409 GMac, 0.900% MACs, 12, 56, kernel_size=(1, 1), stride=(1, 1))
(11): PReLU(0.0 M, 0.437% Params, 0.032 GMac, 0.069% MACs, num_parameters=56)
)
(final): ConvTranspose2d(0.005 M, 35.420% Params, 40.833 GMac, 89.770% MACs, 56, 1, kernel_size=(9, 9), stride=(4, 4), padding=(4, 4), output_padding=(3, 3))
)
Computational complexity: 45.49 GMac
```

My model in tensorflow

```
d=56
s=12
inp = Input((750 ,750, 1))
x = Conv2D(d, (5,5), padding='same')(inp)
x = PReLU()(x)
x = Conv2D(s, (1,1), padding='valid')(x)
x = PReLU()(x)
x = Conv2D(s, (3,3), padding='same')(x)
x = PReLU()(x)
x = Conv2D(s, (3,3), padding='same')(x)
x = PReLU()(x)
x = Conv2D(s, (3,3), padding='same')(x)
x = PReLU()(x)
x = Conv2D(s, (3,3), padding='same')(x)
x = PReLU()(x)
x = Conv2D(d, (1,1), padding='same')(x)
x = PReLU()(x)
out = Conv2DTranspose(1 ,(9,9), strides=(4, 4),padding='same',output_padding = 3)(x)
```

The Flops output in tensorflow is: Profile:

```
node name | # float_ops
Conv2D 8.92b float_ops (100.00%, 61.95%)
Conv2DBackpropInput 5.10b float_ops (38.05%, 35.44%)
Neg 180.00m float_ops (2.61%, 1.25%)
BiasAdd 105.75m float_ops (1.36%, 0.73%)
Mul 90.00m float_ops (0.63%, 0.63%)
======================End of Report==========================
The FLOPs is:14.3 GFlops
```