mirror of https://github.com/hpcaitech/ColossalAI
46 lines
1.8 KiB
Python
46 lines
1.8 KiB
Python
import torch
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try:
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import fused_mix_prec_layer_norm_cuda
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except:
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fused_mix_prec_layer_norm_cuda = None
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class FusedLayerNormAffineFunction1D(torch.autograd.Function):
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r"""Layernorm
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Args:
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input: input matrix.
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weight: weight matrix.
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bias: bias matrix.
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normalized_shape: input shape from an expected input of size.
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:math:`[* \times \text{normalized_shape}[0] \times \text{normalized_shape}[1] \times \ldots \times \text{normalized_shape}[-1]]`
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If a single integer is used, it is treated as a singleton list, and this module will
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normalize over the last dimension which is expected to be of that specific size.
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eps: a value added to the denominator for numerical stability
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"""
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@staticmethod
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def forward(ctx, input, weight, bias, normalized_shape, eps):
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ctx.normalized_shape = normalized_shape
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ctx.eps = eps
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input_ = input.contiguous()
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weight_ = weight.contiguous()
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bias_ = bias.contiguous()
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output, mean, invvar = fused_mix_prec_layer_norm_cuda.forward_affine(input_, ctx.normalized_shape, weight_,
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bias_, ctx.eps)
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ctx.save_for_backward(input_, weight_, bias_, mean, invvar)
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return output
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@staticmethod
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def backward(ctx, grad_output):
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input_, weight_, bias_, mean, invvar = ctx.saved_tensors
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grad_input = grad_weight = grad_bias = None
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grad_input, grad_weight, grad_bias \
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= fused_mix_prec_layer_norm_cuda.backward_affine(
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grad_output.contiguous(), mean, invvar,
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input_, ctx.normalized_shape,
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weight_, bias_, ctx.eps)
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return grad_input, grad_weight, grad_bias, None, None
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