use flow.randperm

[Flowingsun007]

用flow.randperm替换np方法

>>> x = flow.randperm(10).tolist()
>>> x
[0, 7, 4, 1, 2, 6, 3, 5, 9, 8]

[github-actions]

Speed stats:

GPU Name: GeForce GTX 1080 

PyTorch resnet50 time: 140.8ms (= 7042.4ms / 50, input_shape=[16, 3, 224, 224], backward is enabled)
OneFlow resnet50 time: 128.0ms (= 6398.1ms / 50, input_shape=[16, 3, 224, 224], backward is enabled)
Relative speed: 1.10 (= 140.8ms / 128.0ms)

PyTorch resnet50 time: 83.2ms (= 4158.8ms / 50, input_shape=[8, 3, 224, 224], backward is enabled)
OneFlow resnet50 time: 74.1ms (= 3705.4ms / 50, input_shape=[8, 3, 224, 224], backward is enabled)
Relative speed: 1.12 (= 83.2ms / 74.1ms)

PyTorch resnet50 time: 56.5ms (= 2826.8ms / 50, input_shape=[4, 3, 224, 224], backward is enabled)
OneFlow resnet50 time: 48.1ms (= 2403.0ms / 50, input_shape=[4, 3, 224, 224], backward is enabled)
Relative speed: 1.18 (= 56.5ms / 48.1ms)

PyTorch resnet50 time: 47.5ms (= 2374.9ms / 50, input_shape=[2, 3, 224, 224], backward is enabled)
OneFlow resnet50 time: 39.4ms (= 1971.5ms / 50, input_shape=[2, 3, 224, 224], backward is enabled)
Relative speed: 1.20 (= 47.5ms / 39.4ms)

PyTorch resnet50 time: 43.5ms (= 2173.7ms / 50, input_shape=[1, 3, 224, 224], backward is enabled)
OneFlow resnet50 time: 37.6ms (= 1879.4ms / 50, input_shape=[1, 3, 224, 224], backward is enabled)
Relative speed: 1.16 (= 43.5ms / 37.6ms)