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from collections import OrderedDict |
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import math |
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from typing import Callable, Optional, Sequence, Tuple, Text |
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import torch |
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from torch import nn |
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from torch.nn import functional as F |
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from torch.utils.checkpoint import checkpoint |
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import numbers |
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import einops |
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import numpy as np |
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from misc import to_2tuple |
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class LayerNorm(nn.Module): |
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"""Subclass torch's LayerNorm (with cast back to input dtype).""" |
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def __init__( |
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self, |
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normalized_shape, |
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eps: float = 1e-5, |
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elementwise_affine: bool = True, |
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device=None, |
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dtype=None, |
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): |
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super().__init__() |
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if isinstance(normalized_shape, numbers.Integral): |
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normalized_shape = (normalized_shape,) |
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self.normalized_shape = tuple(normalized_shape) |
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self.eps = eps |
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self.elementwise_affine = elementwise_affine |
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if self.elementwise_affine: |
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self.weight = torch.nn.Parameter( |
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torch.empty(self.normalized_shape) |
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) |
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self.bias = torch.nn.Parameter( |
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torch.empty(self.normalized_shape) |
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) |
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else: |
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self.register_parameter("weight", None) |
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self.register_parameter("bias", None) |
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def forward(self, x: torch.Tensor): |
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orig_type = x.dtype |
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assert self.normalized_shape == x.shape[-len(self.normalized_shape):] |
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dims = [-(i + 1) for i in range(len(self.normalized_shape))] |
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mean = x.mean(dim=dims, keepdim=True) |
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mean_x2 = (x**2).mean(dim=dims, keepdim=True) |
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var = mean_x2 - mean**2 |
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x_norm = (x - mean) / torch.sqrt(var + self.eps) |
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if self.elementwise_affine: |
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x_norm = self.weight * x_norm + self.bias |
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return x_norm.to(orig_type) |
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class QuickGELU(nn.Module): |
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def forward(self, x: torch.Tensor): |
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return x * torch.sigmoid(1.702 * x) |
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class LayerScale(nn.Module): |
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def __init__(self, dim, init_values=1e-5, inplace=False): |
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super().__init__() |
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self.inplace = inplace |
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self.gamma = nn.Parameter(init_values * torch.ones(dim)) |
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def forward(self, x): |
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raise ValueError("Not implemented") |
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return x.mul_(self.gamma) if self.inplace else x * self.gamma |
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class PatchDropout(nn.Module): |
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""" |
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https://arxiv.org/abs/2212.00794 |
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""" |
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def __init__(self, prob, exclude_first_token=True): |
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super().__init__() |
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assert 0 <= prob < 1.0 |
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self.prob = prob |
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self.exclude_first_token = exclude_first_token |
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def forward(self, x): |
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if not self.training or self.prob == 0.0: |
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return x |
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if self.exclude_first_token: |
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cls_tokens, x = x[:, :1], x[:, 1:] |
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else: |
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cls_tokens = torch.jit.annotate(torch.Tensor, x[:, :1]) |
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batch = x.size()[0] |
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num_tokens = x.size()[1] |
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batch_indices = torch.arange(batch) |
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batch_indices = batch_indices[..., None] |
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keep_prob = 1 - self.prob |
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num_patches_keep = max(1, int(num_tokens * keep_prob)) |
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rand = torch.randn(batch, num_tokens) |
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patch_indices_keep = rand.topk(num_patches_keep, dim=-1).indices |
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x = x[batch_indices, patch_indices_keep] |
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if self.exclude_first_token: |
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x = torch.cat((cls_tokens, x), dim=1) |
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return x |
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class Attention(nn.Module): |
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def __init__( |
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self, |
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dim, |
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num_heads=8, |
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qkv_bias=True, |
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scaled_cosine=False, |
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scale_heads=False, |
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logit_scale_max=math.log(1.0 / 0.01), |
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attn_drop=0.0, |
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proj_drop=0.0, |
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): |
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super().__init__() |
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self.scaled_cosine = scaled_cosine |
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self.scale_heads = scale_heads |
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assert dim % num_heads == 0, "dim should be divisible by num_heads" |
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self.num_heads = num_heads |
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self.head_dim = dim // num_heads |
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self.scale = self.head_dim**-0.5 |
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self.logit_scale_max = logit_scale_max |
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self.in_proj_weight = nn.Parameter(torch.randn((dim * 3, dim)) * self.scale) |
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if qkv_bias: |
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self.in_proj_bias = nn.Parameter(torch.zeros(dim * 3)) |
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else: |
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self.in_proj_bias = None |
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if self.scaled_cosine: |
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self.logit_scale = nn.Parameter( |
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torch.log(10 * torch.ones((num_heads, 1, 1))) |
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) |
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else: |
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self.logit_scale = None |
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self.attn_drop = nn.Dropout(attn_drop) |
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if self.scale_heads: |
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self.head_scale = nn.Parameter(torch.ones((num_heads, 1, 1))) |
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else: |
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self.head_scale = None |
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self.out_proj = nn.Linear(dim, dim) |
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self.out_drop = nn.Dropout(proj_drop) |
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def forward(self, x, attn_mask: Optional[torch.Tensor] = None): |
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L, N, C = x.shape |
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q, k, v = F.linear(x, self.in_proj_weight, self.in_proj_bias).chunk(3, dim=-1) |
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q = q.contiguous().view(L, N * self.num_heads, -1).transpose(0, 1) |
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k = k.contiguous().view(L, N * self.num_heads, -1).transpose(0, 1) |
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v = v.contiguous().view(L, N * self.num_heads, -1).transpose(0, 1) |
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if self.logit_scale is not None: |
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attn = torch.bmm( |
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F.normalize(q, dim=-1), F.normalize(k, dim=-1).transpose(-1, -2) |
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) |
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logit_scale = torch.clamp(self.logit_scale, max=self.logit_scale_max).exp() |
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attn = attn.view(N, self.num_heads, L, L) * logit_scale |
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attn = attn.view(-1, L, L) |
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else: |
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q = q * self.scale |
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attn = torch.bmm(q, k.transpose(-1, -2)) |
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if attn_mask is not None: |
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if attn_mask.dtype == torch.bool: |
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new_attn_mask = torch.zeros_like(attn_mask, dtype=q.dtype) |
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new_attn_mask.masked_fill_(attn_mask, float("-inf")) |
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attn_mask = new_attn_mask |
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attn += attn_mask |
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attn = attn.softmax(dim=-1) |
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attn = self.attn_drop(attn) |
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x = torch.bmm(attn, v) |
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if self.head_scale is not None: |
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x = x.view(N, self.num_heads, L, C) * self.head_scale |
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x = x.view(-1, L, C) |
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x = x.transpose(0, 1).reshape(L, N, C) |
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x = self.out_proj(x) |
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x = self.out_drop(x) |
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return x |
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class AttentionalPooler(nn.Module): |
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def __init__( |
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self, |
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d_model: int, |
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context_dim: int, |
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n_head: int = 8, |
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n_queries: int = 256, |
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norm_layer: Callable = LayerNorm, |
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): |
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super().__init__() |
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self.query = nn.Parameter(torch.randn(n_queries, d_model)) |
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self.attn = nn.MultiheadAttention( |
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d_model, n_head, kdim=context_dim, vdim=context_dim |
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) |
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self.ln_q = norm_layer(d_model) |
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self.ln_k = norm_layer(context_dim) |
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def forward(self, x: torch.Tensor): |
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x = self.ln_k(x).permute(1, 0, 2) |
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N = x.shape[1] |
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q = self.ln_q(self.query) |
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out = self.attn(self._repeat(q, N), x, x, need_weights=False)[0] |
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return out.permute(1, 0, 2) |
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def _repeat(self, query, N: int): |
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return query.unsqueeze(1).repeat(1, N, 1) |
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class MLP(nn.Module): |
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def __init__( |
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self, |
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d_model: int, |
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mlp_width: int, |
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act_layer: Callable = nn.GELU, |
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layer_id: Optional[int] = None, |
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): |
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super().__init__() |
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self.c_fc = nn.Linear(d_model, mlp_width) |
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self.gelu = act_layer() |
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self.c_proj = nn.Linear(mlp_width, d_model) |
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self.layer_id = layer_id |
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def forward(self, x, neuron_dict=None, num_register_tokens=0): |
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x = self.c_fc(x) |
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if neuron_dict is not None and self.layer_id in neuron_dict and num_register_tokens>0: |
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neurons = neuron_dict[self.layer_id] |
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x_after_gelu = self.gelu(x) |
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original_activations = x_after_gelu.clone() |
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new_activation_map = torch.zeros( |
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(x_after_gelu.shape[0], x_after_gelu.shape[1], len(neurons)), |
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device=x_after_gelu.device, |
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).to(x_after_gelu.dtype) |
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max_values = torch.max(original_activations[:, :, neurons], dim=1, keepdim=True).values |
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new_activation_map[:, -num_register_tokens:, :] = max_values |
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new_activation_map[:,0,:] = x_after_gelu[:,0,neurons] |
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x_after_gelu[:,:,neurons] = new_activation_map |
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x = x_after_gelu |
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else: |
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x = self.gelu(x) |
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x = self.c_proj(x) |
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return x |
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class MultiheadAttention(nn.Module): |
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def __init__( |
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self, |
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embed_dim, |
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num_heads, |
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dropout=0.0, |
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bias=True, |
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add_bias_kv=False, |
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add_zero_attn=False, |
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kdim=None, |
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vdim=None, |
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batch_first=False, |
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device=None, |
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dtype=None, |
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): |
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super().__init__() |
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self.embed_dim = embed_dim |
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self.kdim = kdim if kdim is not None else embed_dim |
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self.vdim = vdim if vdim is not None else embed_dim |
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self._qkv_same_embed_dim = self.kdim == embed_dim and self.vdim == embed_dim |
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self.q_out = nn.Identity() |
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self.k_out = nn.Identity() |
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self.v_out = nn.Identity() |
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self.qkv_out = nn.Identity() |
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self.attn_map = nn.Identity() |
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self.num_heads = num_heads |
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self.dropout = dropout |
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self.batch_first = batch_first |
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self.head_dim = embed_dim // num_heads |
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assert ( |
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self.head_dim * num_heads == self.embed_dim |
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), "embed_dim must be divisible by num_heads" |
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self.in_proj_weight = nn.Parameter(torch.empty((3 * embed_dim, embed_dim))) |
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if bias: |
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self.in_proj_bias = nn.Parameter(torch.empty(3 * embed_dim)) |
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else: |
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self.register_parameter("in_proj_bias", None) |
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self.out_proj = nn.Linear(embed_dim, embed_dim, bias=bias) |
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if add_bias_kv: |
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self.bias_k = nn.Parameter(torch.empty((1, 1, embed_dim))) |
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self.bias_v = nn.Parameter(torch.empty((1, 1, embed_dim))) |
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else: |
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self.bias_k = self.bias_v = None |
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self.add_zero_attn = add_zero_attn |
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def forward_direct(self, x, attn_mask=None): |
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B, N, C = x.shape |
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qkv = x @ self.in_proj_weight.T + self.in_proj_bias |
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qkv = self.qkv_out(qkv) |
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qkv = qkv.reshape(B, N, 3, self.num_heads, self.head_dim).permute(2, 0, 3, 1, 4) |
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q, k, v = qkv.unbind(0) |
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q = self.q_out(q) |
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k = self.k_out(k) |
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v = self.v_out(v) |
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dk = q.size()[-1] |
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q = q / math.sqrt(dk) |
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attn = q @ k.transpose(-2, -1) |
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if attn_mask is not None: |
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attn += attn_mask |
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attn = attn.softmax(dim=-1) |
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attn = self.attn_map(attn) |
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x = attn @ v |
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x = x.transpose(1, 2).reshape(B, N, C) |
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x = x @ self.out_proj.weight.T + self.out_proj.bias |
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return x |
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def _split_qkv_weight(self): |
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q_weight, k_weight, v_weight = ( |
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self.in_proj_weight[: self.embed_dim].reshape( |
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self.num_heads, self.head_dim, -1 |
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), |
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self.in_proj_weight[self.embed_dim : self.embed_dim * 2].reshape( |
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self.num_heads, self.head_dim, -1 |
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), |
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self.in_proj_weight[self.embed_dim * 2 :].reshape( |
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self.num_heads, self.head_dim, -1 |
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), |
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) |
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return q_weight, k_weight, v_weight |
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def _split_qkv_bias(self): |
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q_bias, k_bias, v_bias = ( |
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self.in_proj_bias[: self.embed_dim].reshape( |
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1, self.num_heads, 1, self.head_dim |
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), |
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self.in_proj_bias[self.embed_dim : self.embed_dim * 2].reshape( |
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1, self.num_heads, 1, self.head_dim |
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), |
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self.in_proj_bias[self.embed_dim * 2 :].reshape( |
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1, self.num_heads, 1, self.head_dim |
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), |
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) |
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return q_bias, k_bias, v_bias |
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def forward_qkv(self, x, attn_mask=None): |
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B, N, C = x.shape |
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q_weight, k_weight, v_weight = ( |
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self.in_proj_weight[: self.embed_dim], |
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self.in_proj_weight[self.embed_dim : self.embed_dim * 2], |
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self.in_proj_weight[self.embed_dim * 2 :], |
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) |
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q_bias, k_bias, v_bias = ( |
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self.in_proj_bias[: self.embed_dim], |
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self.in_proj_bias[self.embed_dim : self.embed_dim * 2], |
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self.in_proj_bias[self.embed_dim * 2 :], |
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) |
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q = (x @ q_weight.T + q_bias).reshape(B, N, self.num_heads, self.head_dim).permute(0, 2, 1, 3) |
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k = (x @ k_weight.T + k_bias).reshape(B, N, self.num_heads, self.head_dim).permute(0, 2, 1, 3) |
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v = (x @ v_weight.T + v_bias).reshape(B, N, self.num_heads, self.head_dim).permute(0, 2, 1, 3) |
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dk = q.size()[-1] |
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q = q / math.sqrt(dk) |
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attn = q @ k.transpose(-2, -1) |
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if attn_mask is not None: |
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attn += attn_mask |
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attn = attn.softmax(dim=-1) |
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x = torch.einsum("bhnm,bhmc->bhnmc", attn, v) |
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x = x.sum(axis=3).transpose(1, 2).reshape(B, N, C) |
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x = x @ self.out_proj.weight.T + self.out_proj.bias |
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return x |
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def forward_per_head(self, x, attn_mask=None): |
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B, N, C = x.shape |
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q_weight, k_weight, v_weight = self._split_qkv_weight() |
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q_bias, k_bias, v_bias = self._split_qkv_bias() |
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q = torch.einsum("bnc,hdc->bhnd", x, q_weight) + q_bias |
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k = torch.einsum("bnc,hdc->bhnd", x, k_weight) + k_bias |
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v = torch.einsum("bnc,hdc->bhnd", x, v_weight) + v_bias |
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dk = q.size()[-1] |
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q = q / math.sqrt(dk) |
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attn = q @ k.transpose(-2, -1) |
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if attn_mask is not None: |
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attn += attn_mask |
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attn = attn.softmax(dim=-1) |
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x = torch.einsum("bhnm,bhmc->bnmhc", attn, v) |
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x = torch.einsum( |
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"bnmhc,dhc->bnmhd", |
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x, |
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self.out_proj.weight.reshape(self.embed_dim, self.num_heads, self.head_dim), |
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) |
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x = x.sum(axis=[2, 3]) + self.out_proj.bias |
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return x |
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def _get_ov_circuit(self): |
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reshaped_o = self.out_proj.weight.reshape( |
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self.embed_dim, self.num_heads, self.head_dim |
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) |
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_, _, v_weight = self._split_qkv_weight() |
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_, _, v_bias = self._split_qkv_bias() |
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ov_circuit = torch.einsum("onh,nhi->oni", reshaped_o, v_weight) |
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ov_bias_circuit = torch.einsum("onh,bnxh->bnxo", reshaped_o, v_bias) |
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return ov_circuit, ov_bias_circuit |
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def forward_ov_circuit(self, x, attn_mask=None): |
|
|
B, N, C = x.shape |
|
|
q_weight, k_weight, _ = self._split_qkv_weight() |
|
|
q_bias, k_bias, _ = self._split_qkv_bias() |
|
|
q = torch.einsum("bnc,hdc->bhnd", x, q_weight) + q_bias |
|
|
k = torch.einsum("bnc,hdc->bhnd", x, k_weight) + k_bias |
|
|
ov, ov_bias = self._get_ov_circuit() |
|
|
v = torch.einsum("bnc,dhc->bhnd", x, ov) + ov_bias |
|
|
|
|
|
dk = q.size()[-1] |
|
|
q = q / math.sqrt(dk) |
|
|
attn = q @ k.transpose(-2, -1) |
|
|
if attn_mask is not None: |
|
|
attn += attn_mask |
|
|
attn = attn.softmax(dim=-1) |
|
|
x = torch.einsum("bhnm,bhmc->bnmhc", attn, v) |
|
|
x = x.sum(axis=[2, 3]) + self.out_proj.bias |
|
|
return x |
|
|
|
|
|
def forward(self, x, attn_mask=None, method: Text = "ov_circuit"): |
|
|
if method == "direct": |
|
|
return self.forward_direct(x, attn_mask=attn_mask) |
|
|
elif method == "qkv": |
|
|
return self.forward_qkv(x, attn_mask=attn_mask) |
|
|
elif method == "head": |
|
|
return self.forward_per_head(x, attn_mask=attn_mask) |
|
|
elif method == "ov_circuit": |
|
|
return self.forward_ov_circuit(x, attn_mask=attn_mask) |
|
|
|
|
|
|
|
|
class ResidualAttentionBlock(nn.Module): |
|
|
def __init__( |
|
|
self, |
|
|
d_model: int, |
|
|
n_head: int, |
|
|
mlp_ratio: float = 4.0, |
|
|
ls_init_value: float = None, |
|
|
act_layer: Callable = nn.GELU, |
|
|
norm_layer: Callable = LayerNorm, |
|
|
layer_id: Optional[int] = None, |
|
|
): |
|
|
super().__init__() |
|
|
self.ln_1 = norm_layer(d_model) |
|
|
self.attn = MultiheadAttention(d_model, n_head) |
|
|
self.layer_id = layer_id |
|
|
|
|
|
self.ls_1 = ( |
|
|
LayerScale(d_model, ls_init_value) |
|
|
if ls_init_value is not None |
|
|
else nn.Identity() |
|
|
) |
|
|
|
|
|
self.ln_2 = norm_layer(d_model) |
|
|
self.mlp_width = int(d_model * mlp_ratio) |
|
|
self.mlp = MLP( |
|
|
d_model, |
|
|
self.mlp_width, |
|
|
act_layer=act_layer, |
|
|
layer_id=layer_id, |
|
|
) |
|
|
self.ls_2 = ( |
|
|
LayerScale(d_model, ls_init_value) |
|
|
if ls_init_value is not None |
|
|
else nn.Identity() |
|
|
) |
|
|
|
|
|
def attention( |
|
|
self, |
|
|
q_x: torch.Tensor, |
|
|
attn_mask: Optional[torch.Tensor] = None, |
|
|
method: Text = "direct", |
|
|
): |
|
|
attn_mask = attn_mask.to(q_x.dtype) if attn_mask is not None else None |
|
|
return self.attn(q_x, attn_mask=attn_mask, method=method) |
|
|
|
|
|
def forward( |
|
|
self, |
|
|
q_x: torch.Tensor, |
|
|
attn_mask: Optional[torch.Tensor] = None, |
|
|
attn_method: Text = "direct", |
|
|
neuron_dict=None, |
|
|
num_register_tokens=0 |
|
|
): |
|
|
after_ln1 = self.ln_1(q_x) |
|
|
after_attn = self.attention( |
|
|
q_x=after_ln1, attn_mask=attn_mask, method=attn_method |
|
|
) |
|
|
x = q_x + self.ls_1(after_attn) |
|
|
after_ln2 = self.ln_2(x) |
|
|
after_mlp = self.mlp(after_ln2, neuron_dict=neuron_dict, num_register_tokens=num_register_tokens) |
|
|
x = x + self.ls_2(after_mlp) |
|
|
return x |
|
|
|
|
|
|
|
|
class Transformer(nn.Module): |
|
|
def __init__( |
|
|
self, |
|
|
width: int, |
|
|
layers: int, |
|
|
heads: int, |
|
|
mlp_ratio: float = 4.0, |
|
|
ls_init_value: float = None, |
|
|
act_layer: Callable = nn.GELU, |
|
|
norm_layer: Callable = LayerNorm, |
|
|
): |
|
|
super().__init__() |
|
|
self.width = width |
|
|
self.layers = layers |
|
|
self.grad_checkpointing = False |
|
|
|
|
|
self.resblocks = nn.ModuleList( |
|
|
[ |
|
|
ResidualAttentionBlock( |
|
|
width, |
|
|
heads, |
|
|
mlp_ratio, |
|
|
ls_init_value=ls_init_value, |
|
|
act_layer=act_layer, |
|
|
norm_layer=norm_layer, |
|
|
layer_id=i, |
|
|
) |
|
|
for i in range(layers) |
|
|
] |
|
|
) |
|
|
|
|
|
def get_cast_dtype(self) -> torch.dtype: |
|
|
if hasattr(self.resblocks[0].mlp.c_fc, "int8_original_dtype"): |
|
|
return self.resblocks[0].mlp.c_fc.int8_original_dtype |
|
|
return self.resblocks[0].mlp.c_fc.weight.dtype |
|
|
|
|
|
def forward( |
|
|
self, |
|
|
x: torch.Tensor, |
|
|
attn_mask: Optional[torch.Tensor] = None, |
|
|
attn_method: Text = "direct", |
|
|
neuron_dict=None, |
|
|
num_register_tokens=0, |
|
|
get_hidden_states: bool = False, |
|
|
): |
|
|
if "hidden_states" not in locals(): |
|
|
hidden_states = [] |
|
|
hidden_states.append(x) |
|
|
for r in self.resblocks: |
|
|
if self.grad_checkpointing and not torch.jit.is_scripting(): |
|
|
raise ValueError("grad_checkpointing not implemented") |
|
|
else: |
|
|
x = r( |
|
|
x, |
|
|
attn_mask=attn_mask, |
|
|
attn_method=attn_method, |
|
|
neuron_dict=neuron_dict, |
|
|
num_register_tokens=num_register_tokens |
|
|
) |
|
|
if get_hidden_states: |
|
|
hidden_states.append(x) |
|
|
|
|
|
if get_hidden_states: |
|
|
return { |
|
|
"hidden_states": hidden_states, |
|
|
"last_hidden_state": x, |
|
|
} |
|
|
else: |
|
|
return x |
|
|
|
|
|
|
|
|
class VisionTransformer(nn.Module): |
|
|
output_tokens: torch.jit.Final[bool] |
|
|
|
|
|
def __init__( |
|
|
self, |
|
|
image_size: int, |
|
|
patch_size: int, |
|
|
width: int, |
|
|
layers: int, |
|
|
heads: int, |
|
|
mlp_ratio: float, |
|
|
ls_init_value: float = None, |
|
|
global_average_pool: bool = False, |
|
|
attentional_pool: bool = False, |
|
|
n_queries: int = 256, |
|
|
attn_pooler_heads: int = 8, |
|
|
output_dim: int = 512, |
|
|
patch_dropout: float = 0.0, |
|
|
input_patchnorm: bool = False, |
|
|
act_layer: Callable = nn.GELU, |
|
|
norm_layer: Callable = LayerNorm, |
|
|
output_tokens: bool = False, |
|
|
): |
|
|
super().__init__() |
|
|
self.output_tokens = output_tokens |
|
|
image_height, image_width = self.image_size = to_2tuple(image_size) |
|
|
patch_height, patch_width = self.patch_size = to_2tuple(patch_size) |
|
|
self.grid_size = (image_height // patch_height, image_width // patch_width) |
|
|
self.output_dim = output_dim |
|
|
|
|
|
self.num_register_tokens = 0 |
|
|
self.neuron_dict = None |
|
|
|
|
|
self.input_patchnorm = input_patchnorm |
|
|
|
|
|
if input_patchnorm: |
|
|
patch_input_dim = patch_height * patch_width * 3 |
|
|
self.patchnorm_pre_ln = LayerNorm(patch_input_dim) |
|
|
self.conv1 = nn.Linear(patch_input_dim, width) |
|
|
else: |
|
|
self.patchnorm_pre_ln = nn.Identity() |
|
|
self.conv1 = nn.Conv2d( |
|
|
in_channels=3, |
|
|
out_channels=width, |
|
|
kernel_size=patch_size, |
|
|
stride=patch_size, |
|
|
bias=False, |
|
|
) |
|
|
|
|
|
scale = width**-0.5 |
|
|
self.class_embedding = nn.Parameter(scale * torch.randn(width)) |
|
|
self.positional_embedding = nn.Parameter( |
|
|
scale * torch.randn(self.grid_size[0] * self.grid_size[1] + 1, width) |
|
|
) |
|
|
|
|
|
self.width = width |
|
|
self.scale = scale |
|
|
self.extra_token = self.scale * torch.randn(width) |
|
|
|
|
|
self.patch_dropout = ( |
|
|
PatchDropout(patch_dropout) if patch_dropout > 0.0 else nn.Identity() |
|
|
) |
|
|
|
|
|
self.ln_pre = norm_layer(width) |
|
|
self.transformer = Transformer( |
|
|
width, |
|
|
layers, |
|
|
heads, |
|
|
mlp_ratio, |
|
|
ls_init_value=ls_init_value, |
|
|
act_layer=act_layer, |
|
|
norm_layer=norm_layer, |
|
|
) |
|
|
|
|
|
self.global_average_pool = global_average_pool |
|
|
if attentional_pool: |
|
|
self.attn_pool = AttentionalPooler( |
|
|
output_dim, width, n_head=attn_pooler_heads, n_queries=n_queries |
|
|
) |
|
|
self.ln_post = norm_layer(output_dim) |
|
|
self.proj = nn.Parameter(scale * torch.randn(output_dim, output_dim)) |
|
|
else: |
|
|
self.attn_pool = None |
|
|
self.ln_post = norm_layer(width) |
|
|
self.proj = nn.Parameter(scale * torch.randn(width, output_dim)) |
|
|
|
|
|
@torch.jit.ignore |
|
|
def set_grad_checkpointing(self, enable=True): |
|
|
self.transformer.grad_checkpointing = enable |
|
|
|
|
|
def _global_pool(self, x: torch.Tensor) -> Tuple[torch.Tensor, torch.Tensor]: |
|
|
if self.global_average_pool: |
|
|
return x.mean(dim=1), x |
|
|
else: |
|
|
return x[:, 0], x[:, 1:] |
|
|
|
|
|
|
|
|
def forward(self, x: torch.Tensor, attn_method: Text = "direct", num_register_tokens = None, neuron_dict=None, get_hidden_states:bool=False): |
|
|
|
|
|
|
|
|
if num_register_tokens is None and neuron_dict is None: |
|
|
num_register_tokens = self.num_register_tokens |
|
|
neuron_dict = self.neuron_dict |
|
|
|
|
|
if self.input_patchnorm: |
|
|
x = x.reshape( |
|
|
x.shape[0], |
|
|
x.shape[1], |
|
|
self.grid_size[0], |
|
|
self.patch_size[0], |
|
|
self.grid_size[1], |
|
|
self.patch_size[1], |
|
|
) |
|
|
x = x.permute(0, 2, 4, 1, 3, 5) |
|
|
x = x.reshape(x.shape[0], self.grid_size[0] * self.grid_size[1], -1) |
|
|
x = self.patchnorm_pre_ln(x) |
|
|
x = self.conv1(x) |
|
|
else: |
|
|
x = self.conv1(x) |
|
|
x = x.reshape(x.shape[0], x.shape[1], -1) |
|
|
x = x.permute(0, 2, 1) |
|
|
|
|
|
|
|
|
x = torch.cat([ |
|
|
self.class_embedding.to(x.dtype) |
|
|
+ torch.zeros( |
|
|
x.shape[0], 1, x.shape[-1], dtype=x.dtype, device=x.device |
|
|
), |
|
|
x, |
|
|
], |
|
|
dim=1, |
|
|
) |
|
|
x = x + self.positional_embedding.to(x.dtype) |
|
|
|
|
|
extra_token_embeddings = [] |
|
|
total_patches = x.shape[1] - 1 |
|
|
for i in range(num_register_tokens): |
|
|
extra_token_embeddings.append( |
|
|
torch.zeros( |
|
|
x.shape[0], 1, x.shape[-1], dtype=x.dtype, device=x.device |
|
|
), |
|
|
) |
|
|
|
|
|
|
|
|
if num_register_tokens > 0: |
|
|
x = torch.cat([x, *extra_token_embeddings], dim=1) |
|
|
|
|
|
x = self.patch_dropout(x) |
|
|
x = self.ln_pre(x) |
|
|
|
|
|
|
|
|
if get_hidden_states: |
|
|
ret = self.transformer(x, attn_mask=None, attn_method=attn_method, neuron_dict=neuron_dict, num_register_tokens=num_register_tokens,get_hidden_states=get_hidden_states) |
|
|
|
|
|
hidden_states = ret["hidden_states"] |
|
|
x = ret["last_hidden_state"] |
|
|
else: |
|
|
x = self.transformer(x, attn_mask=None, attn_method=attn_method, neuron_dict=neuron_dict, num_register_tokens=num_register_tokens,get_hidden_states=get_hidden_states) |
|
|
|
|
|
if self.attn_pool is not None: |
|
|
x = self.attn_pool(x) |
|
|
x = self.ln_post(x) |
|
|
pooled, tokens = self._global_pool(x) |
|
|
else: |
|
|
pooled, tokens = self._global_pool(x) |
|
|
pooled = self.ln_post(pooled) |
|
|
|
|
|
if self.proj is not None: |
|
|
pooled = pooled @ self.proj |
|
|
|
|
|
if self.output_tokens: |
|
|
return pooled, tokens |
|
|
|
|
|
if get_hidden_states: |
|
|
return { |
|
|
"pooled": pooled, |
|
|
"tokens": tokens, |
|
|
"hidden_states": hidden_states |
|
|
} |
|
|
|
|
|
return pooled |
|
|
|
|
|
|
|
|
class TextTransformer(nn.Module): |
|
|
output_tokens: torch.jit.Final[bool] |
|
|
|
|
|
def __init__( |
|
|
self, |
|
|
context_length: int = 77, |
|
|
vocab_size: int = 49408, |
|
|
width: int = 512, |
|
|
heads: int = 8, |
|
|
layers: int = 12, |
|
|
ls_init_value: float = None, |
|
|
output_dim: int = 512, |
|
|
act_layer: Callable = nn.GELU, |
|
|
norm_layer: Callable = LayerNorm, |
|
|
embed_cls: bool = False, |
|
|
pad_id: int = 0, |
|
|
output_tokens: bool = False, |
|
|
): |
|
|
super().__init__() |
|
|
self.output_tokens = output_tokens |
|
|
self.num_pos = self.context_length = context_length |
|
|
self.vocab_size = vocab_size |
|
|
self.width = width |
|
|
self.output_dim = output_dim |
|
|
self.heads = heads |
|
|
self.pad_id = pad_id |
|
|
|
|
|
self.text_projection = nn.Parameter(torch.empty(width, output_dim)) |
|
|
|
|
|
if embed_cls: |
|
|
self.cls_emb = nn.Parameter(torch.empty(width)) |
|
|
self.num_pos += 1 |
|
|
else: |
|
|
self.cls_emb = None |
|
|
|
|
|
self.token_embedding = nn.Embedding(vocab_size, width) |
|
|
self.positional_embedding = nn.Parameter(torch.empty(self.num_pos, width)) |
|
|
self.transformer = Transformer( |
|
|
width=width, |
|
|
layers=layers, |
|
|
heads=heads, |
|
|
ls_init_value=ls_init_value, |
|
|
act_layer=act_layer, |
|
|
norm_layer=norm_layer, |
|
|
) |
|
|
self.ln_final = norm_layer(width) |
|
|
|
|
|
self.register_buffer("attn_mask", self.build_attention_mask(), persistent=False) |
|
|
|
|
|
self.init_parameters() |
|
|
|
|
|
def init_parameters(self): |
|
|
nn.init.normal_(self.token_embedding.weight, std=0.02) |
|
|
nn.init.normal_(self.positional_embedding, std=0.01) |
|
|
if self.cls_emb is not None: |
|
|
nn.init.normal_(self.cls_emb, std=0.01) |
|
|
|
|
|
proj_std = (self.transformer.width**-0.5) * ( |
|
|
(2 * self.transformer.layers) ** -0.5 |
|
|
) |
|
|
attn_std = self.transformer.width**-0.5 |
|
|
fc_std = (2 * self.transformer.width) ** -0.5 |
|
|
for block in self.transformer.resblocks: |
|
|
nn.init.normal_(block.attn.in_proj_weight, std=attn_std) |
|
|
nn.init.normal_(block.attn.out_proj.weight, std=proj_std) |
|
|
nn.init.normal_(block.mlp.c_fc.weight, std=fc_std) |
|
|
nn.init.normal_(block.mlp.c_proj.weight, std=proj_std) |
|
|
|
|
|
if self.text_projection is not None: |
|
|
nn.init.normal_(self.text_projection, std=self.transformer.width**-0.5) |
|
|
|
|
|
@torch.jit.ignore |
|
|
def set_grad_checkpointing(self, enable=True): |
|
|
self.transformer.grad_checkpointing = enable |
|
|
|
|
|
def build_attention_mask(self): |
|
|
mask = torch.empty(self.num_pos, self.num_pos) |
|
|
mask.fill_(float("-inf")) |
|
|
mask.triu_(1) |
|
|
return mask |
|
|
|
|
|
def build_cls_mask(self, text, cast_dtype: torch.dtype): |
|
|
cls_mask = (text != self.pad_id).unsqueeze(1) |
|
|
cls_mask = F.pad(cls_mask, (1, 0, cls_mask.shape[2], 0), value=1.0) |
|
|
additive_mask = torch.empty( |
|
|
cls_mask.shape, dtype=cast_dtype, device=cls_mask.device |
|
|
) |
|
|
additive_mask.fill_(0) |
|
|
additive_mask.masked_fill_(~cls_mask, float("-inf")) |
|
|
additive_mask = torch.repeat_interleave(additive_mask, self.heads, 0) |
|
|
return additive_mask |
|
|
|
|
|
def _repeat(self, t, N: int): |
|
|
return t.reshape(1, 1, -1).repeat(N, 1, 1) |
|
|
|
|
|
def forward(self, text, attn_method: Text = "direct"): |
|
|
cast_dtype = self.transformer.get_cast_dtype() |
|
|
seq_len = text.shape[1] |
|
|
|
|
|
x = self.token_embedding(text).to(cast_dtype) |
|
|
attn_mask = self.attn_mask |
|
|
if self.cls_emb is not None: |
|
|
seq_len += 1 |
|
|
x = torch.cat([x, self._repeat(self.cls_emb, x.shape[0])], dim=1) |
|
|
cls_mask = self.build_cls_mask(text, cast_dtype) |
|
|
attn_mask = ( |
|
|
attn_mask[None, :seq_len, :seq_len] + cls_mask[:, :seq_len, :seq_len] |
|
|
) |
|
|
|
|
|
x = x + self.positional_embedding[:seq_len].to(cast_dtype) |
|
|
x = self.transformer(x, attn_mask=attn_mask, attn_method=attn_method) |
|
|
|
|
|
if self.cls_emb is not None: |
|
|
pooled, tokens = x[:, -1], x[:, :-1] |
|
|
pooled = self.ln_final(pooled) |
|
|
else: |
|
|
x = self.ln_final(x) |
|
|
pooled, tokens = x[torch.arange(x.shape[0]), text.argmax(dim=-1)], x |
|
|
|
|
|
if self.text_projection is not None: |
|
|
pooled = pooled @ self.text_projection |
|
|
|
|
|
if self.output_tokens: |
|
|
return pooled, tokens |
|
|
|
|
|
return pooled |