add model

config.json

@@ -0,0 +1,37 @@
+{
+  "activation": "gelu",
+  "architectures": [
+    "DistilBertForSequenceClassification"
+  ],
+  "attention_dropout": 0.1,
+  "auto_map": {
+    "AutoConfig": "configuration_distilbert_ane.DistilBertConfig",
+    "AutoModelForSequenceClassification": "modeling_distilbert_ane.DistilBertForSequenceClassification"
+  },
+  "dim": 768,
+  "dropout": 0.1,
+  "finetuning_task": "sst-2",
+  "hidden_dim": 3072,
+  "id2label": {
+    "0": "NEGATIVE",
+    "1": "POSITIVE"
+  },
+  "initializer_range": 0.02,
+  "label2id": {
+    "NEGATIVE": 0,
+    "POSITIVE": 1
+  },
+  "max_position_embeddings": 512,
+  "model_type": "distilbert",
+  "n_heads": 12,
+  "n_layers": 6,
+  "output_past": true,
+  "pad_token_id": 0,
+  "qa_dropout": 0.1,
+  "seq_classif_dropout": 0.2,
+  "sinusoidal_pos_embds": false,
+  "tie_weights_": true,
+  "torch_dtype": "float32",
+  "transformers_version": "4.20.0.dev0",
+  "vocab_size": 30522
+}

configuration_distilbert_ane.py

@@ -0,0 +1,5 @@
+from transformers.models.distilbert import configuration_distilbert
+
+class DistilBertConfig(configuration_distilbert.DistilBertConfig):
+    def __init__(self, **kwargs):
+        super().__init__(**kwargs)

modeling_distilbert_ane.py

@@ -0,0 +1,625 @@
+# Copyright (C) 2022 Apple Inc. All Rights Reserved.
+
+# IMPORTANT:  This Apple software is supplied to you by Apple
+# Inc. ("Apple") in consideration of your agreement to the following
+# terms, and your use, installation, modification or redistribution of
+# this Apple software constitutes acceptance of these terms.  If you do
+# not agree with these terms, please do not use, install, modify or
+# redistribute this Apple software.
+
+# In consideration of your agreement to abide by the following terms, and
+# subject to these terms, Apple grants you a personal, non-exclusive
+# license, under Apple's copyrights in this original Apple software (the
+# "Apple Software"), to use, reproduce, modify and redistribute the Apple
+# Software, with or without modifications, in source and/or binary forms;
+# provided that if you redistribute the Apple Software in its entirety and
+# without modifications, you must retain this notice and the following
+# text and disclaimers in all such redistributions of the Apple Software.
+# Neither the name, trademarks, service marks or logos of Apple Inc. may
+# be used to endorse or promote products derived from the Apple Software
+# without specific prior written permission from Apple.  Except as
+# expressly stated in this notice, no other rights or licenses, express or
+# implied, are granted by Apple herein, including but not limited to any
+# patent rights that may be infringed by your derivative works or by other
+# works in which the Apple Software may be incorporated.
+
+# The Apple Software is provided by Apple on an "AS IS" basis.  APPLE
+# MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
+# THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND
+# OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
+
+# IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL
+# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,
+# MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED
+# AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),
+# STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+
+import torch
+import torch.nn as nn
+
+from transformers.models.distilbert import modeling_distilbert
+from .configuration_distilbert_ane import DistilBertConfig
+
+# Note: Original implementation of distilbert uses an epsilon value of 1e-12
+# which is not friendly with the float16 precision that ANE uses by default
+EPS = 1e-7
+
+WARN_MSG_FOR_TRAINING_ATTEMPT = \
+    "This model is optimized for on-device execution only. " \
+    "Please use the original implementation from Hugging Face for training"
+
+WARN_MSG_FOR_DICT_RETURN = \
+    "coremltools does not support dict outputs. Please set return_dict=False"
+
+
+class LayerNormANE(nn.Module):
+    """ LayerNorm optimized for Apple Neural Engine (ANE) execution
+
+    Note: This layer only supports normalization over the final dim. It expects `num_channels`
+    as an argument and not `normalized_shape` which is used by `torch.nn.LayerNorm`.
+    """
+
+    def __init__(self,
+                 num_channels,
+                 clip_mag=None,
+                 eps=1e-5,
+                 elementwise_affine=True):
+        """
+        Args:
+            num_channels:       Number of channels (C) where the expected input data format is BC1S. S stands for sequence length.
+            clip_mag:           Optional float value to use for clamping the input range before layer norm is applied.
+                                If specified, helps reduce risk of overflow.
+            eps:                Small value to avoid dividing by zero
+            elementwise_affine: If true, adds learnable channel-wise shift (bias) and scale (weight) parameters
+        """
+        super().__init__()
+        # Principle 1: Picking the Right Data Format (machinelearning.apple.com/research/apple-neural-engine)
+        self.expected_rank = len('BC1S')
+
+        self.num_channels = num_channels
+        self.eps = eps
+        self.clip_mag = clip_mag
+        self.elementwise_affine = elementwise_affine
+
+        if self.elementwise_affine:
+            self.weight = nn.Parameter(torch.Tensor(num_channels))
+            self.bias = nn.Parameter(torch.Tensor(num_channels))
+
+        self._reset_parameters()
+
+    def _reset_parameters(self):
+        if self.elementwise_affine:
+            nn.init.ones_(self.weight)
+            nn.init.zeros_(self.bias)
+
+    def forward(self, inputs):
+        input_rank = len(inputs.size())
+
+        # Principle 1: Picking the Right Data Format (machinelearning.apple.com/research/apple-neural-engine)
+        # Migrate the data format from BSC to BC1S (most conducive to ANE)
+        if input_rank == 3 and inputs.size(2) == self.num_channels:
+            inputs = inputs.transpose(1, 2).unsqueeze(2)
+            input_rank = len(inputs.size())
+
+        assert input_rank == self.expected_rank
+        assert inputs.size(1) == self.num_channels
+
+        if self.clip_mag is not None:
+            inputs.clamp_(-self.clip_mag, self.clip_mag)
+
+        channels_mean = inputs.mean(dim=1, keepdims=True)
+
+        zero_mean = inputs - channels_mean
+
+        zero_mean_sq = zero_mean * zero_mean
+
+        denom = (zero_mean_sq.mean(dim=1, keepdims=True) + self.eps).rsqrt()
+
+        out = zero_mean * denom
+
+        if self.elementwise_affine:
+            out = (out + self.bias.view(1, self.num_channels, 1, 1)
+                   ) * self.weight.view(1, self.num_channels, 1, 1)
+
+        return out
+
+
+class Embeddings(modeling_distilbert.Embeddings):
+    """ Embeddings module optimized for Apple Neural Engine
+    """
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(self, 'LayerNorm', LayerNormANE(config.dim, eps=EPS))
+
+
+class MultiHeadSelfAttention(modeling_distilbert.MultiHeadSelfAttention):
+    """ MultiHeadSelfAttention module optimized for Apple Neural Engine
+    """
+
+    def __init__(self, config):
+        super().__init__(config)
+
+        setattr(
+            self, 'q_lin',
+            nn.Conv2d(
+                in_channels=config.dim,
+                out_channels=config.dim,
+                kernel_size=1,
+            ))
+
+        setattr(
+            self, 'k_lin',
+            nn.Conv2d(
+                in_channels=config.dim,
+                out_channels=config.dim,
+                kernel_size=1,
+            ))
+
+        setattr(
+            self, 'v_lin',
+            nn.Conv2d(
+                in_channels=config.dim,
+                out_channels=config.dim,
+                kernel_size=1,
+            ))
+
+        setattr(
+            self, 'out_lin',
+            nn.Conv2d(
+                in_channels=config.dim,
+                out_channels=config.dim,
+                kernel_size=1,
+            ))
+
+    def prune_heads(self, heads):
+        raise NotImplementedError
+
+    def forward(self,
+                query,
+                key,
+                value,
+                mask,
+                head_mask=None,
+                output_attentions=False):
+        """
+        Parameters:
+            query: torch.tensor(bs, dim, 1, seq_length)
+            key: torch.tensor(bs, dim, 1, seq_length)
+            value: torch.tensor(bs, dim, 1, seq_length)
+            mask: torch.tensor(bs, seq_length) or torch.tensor(bs, seq_length, 1, 1)
+
+        Returns:
+            weights: torch.tensor(bs, n_heads, seq_length, seq_length) Attention weights context: torch.tensor(bs,
+            dim, 1, seq_length) Contextualized layer. Optional: only if `output_attentions=True`
+        """
+        # Parse tensor shapes for source and target sequences
+        assert len(query.size()) == 4 and len(key.size()) == 4 and len(
+            value.size()) == 4
+
+        bs, dim, dummy, seqlen = query.size()
+        # assert seqlen == key.size(3) and seqlen == value.size(3)
+        # assert dim == self.dim
+        # assert dummy == 1
+
+        # Project q, k and v
+        q = self.q_lin(query)
+        k = self.k_lin(key)
+        v = self.v_lin(value)
+
+        # Validate mask
+        if mask is not None:
+            expected_mask_shape = [bs, seqlen, 1, 1]
+            if mask.dtype == torch.bool:
+                mask = mask.logical_not().float() * -1e4
+            elif mask.dtype == torch.int64:
+                mask = (1 - mask).float() * -1e4
+            elif mask.dtype != torch.float32:
+                raise TypeError(f"Unexpected dtype for mask: {mask.dtype}")
+
+            if len(mask.size()) == 2:
+                mask = mask.unsqueeze(2).unsqueeze(2)
+
+            if list(mask.size()) != expected_mask_shape:
+                raise RuntimeError(
+                    f"Invalid shape for `mask` (Expected {expected_mask_shape}, got {list(mask.size())}"
+                )
+
+        if head_mask is not None:
+            raise NotImplementedError
+
+        # Compute scaled dot-product attention
+        dim_per_head = self.dim // self.n_heads
+        mh_q = q.split(
+            dim_per_head,
+            dim=1)  # (bs, dim_per_head, 1, max_seq_length) * n_heads
+        mh_k = k.transpose(1, 3).split(
+            dim_per_head,
+            dim=3)  # (bs, max_seq_length, 1, dim_per_head) * n_heads
+        mh_v = v.split(
+            dim_per_head,
+            dim=1)  # (bs, dim_per_head, 1, max_seq_length) * n_heads
+
+        normalize_factor = float(dim_per_head)**-0.5
+        attn_weights = [
+            torch.einsum('bchq,bkhc->bkhq', [qi, ki]) * normalize_factor
+            for qi, ki in zip(mh_q, mh_k)
+        ]  # (bs, max_seq_length, 1, max_seq_length) * n_heads
+
+        if mask is not None:
+            for head_idx in range(self.n_heads):
+                attn_weights[head_idx] = attn_weights[head_idx] + mask
+
+        attn_weights = [aw.softmax(dim=1) for aw in attn_weights
+                        ]  # (bs, max_seq_length, 1, max_seq_length) * n_heads
+        attn = [
+            torch.einsum('bkhq,bchk->bchq', wi, vi)
+            for wi, vi in zip(attn_weights, mh_v)
+        ]  # (bs, dim_per_head, 1, max_seq_length) * n_heads
+
+        attn = torch.cat(attn, dim=1)  # (bs, dim, 1, max_seq_length)
+
+        attn = self.out_lin(attn)
+
+        if output_attentions:
+            return attn, attn_weights.cat(dim=2)
+        else:
+            return (attn, )
+
+
+class FFN(modeling_distilbert.FFN):
+    """ FFN module optimized for Apple Neural Engine
+    """
+
+    def __init__(self, config):
+        super().__init__(config)
+        self.seq_len_dim = 3
+
+        setattr(
+            self, 'lin1',
+            nn.Conv2d(
+                in_channels=config.dim,
+                out_channels=config.hidden_dim,
+                kernel_size=1,
+            ))
+
+        setattr(
+            self, 'lin2',
+            nn.Conv2d(
+                in_channels=config.hidden_dim,
+                out_channels=config.dim,
+                kernel_size=1,
+            ))
+
+
+class TransformerBlock(modeling_distilbert.TransformerBlock):
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(self, 'attention', MultiHeadSelfAttention(config))
+        setattr(self, 'sa_layer_norm', LayerNormANE(config.dim, eps=EPS))
+        setattr(self, 'ffn', FFN(config))
+        setattr(self, 'output_layer_norm', LayerNormANE(config.dim, eps=EPS))
+
+
+class Transformer(modeling_distilbert.Transformer):
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(
+            self, 'layer',
+            nn.ModuleList(
+                [TransformerBlock(config) for _ in range(config.n_layers)]))
+
+
+class DistilBertModel(modeling_distilbert.DistilBertModel):
+    config_class = DistilBertConfig
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(self, 'embeddings', Embeddings(config))
+        setattr(self, 'transformer', Transformer(config))
+
+        # Register hook for unsqueezing nn.Linear parameters to match nn.Conv2d parameter spec
+        self._register_load_state_dict_pre_hook(linear_to_conv2d_map)
+
+    def _prune_heads(self, heads_to_prune):
+        raise NotImplementedError
+
+
+class DistilBertForMaskedLM(modeling_distilbert.DistilBertForMaskedLM):
+    config_class = DistilBertConfig
+
+    def __init__(self, config):
+        super().__init__(config)
+        from transformers.activations import get_activation
+        setattr(self, 'activation', get_activation(config.activation))
+        setattr(self, 'distilbert', DistilBertModel(config))
+        setattr(self, 'vocab_transform', nn.Conv2d(config.dim, config.dim, 1))
+        setattr(self, 'vocab_layer_norm', LayerNormANE(config.dim, eps=EPS))
+        setattr(self, 'vocab_projector',
+                nn.Conv2d(config.dim, config.vocab_size, 1))
+
+    def forward(
+        self,
+        input_ids=None,
+        attention_mask=None,
+        head_mask=None,
+        inputs_embeds=None,
+        labels=None,
+        output_attentions=None,
+        output_hidden_states=None,
+        return_dict=None,
+    ):
+        if self.training or labels is not None:
+            raise ValueError(WARN_MSG_FOR_TRAINING_ATTEMPT)
+
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+        if return_dict:
+            raise ValueError(WARN_MSG_FOR_DICT_RETURN)
+
+        dlbrt_output = self.distilbert(
+            input_ids=input_ids,
+            attention_mask=attention_mask,
+            head_mask=head_mask,
+            inputs_embeds=inputs_embeds,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=False,
+        )
+        hidden_states = dlbrt_output[0]  # (bs, dim, 1, seq_len)
+        prediction_logits = self.vocab_transform(
+            hidden_states)  # (bs, dim, 1, seq_len)
+        prediction_logits = self.activation(
+            prediction_logits)  # (bs, dim, 1, seq_len)
+        prediction_logits = self.vocab_layer_norm(
+            prediction_logits)  # (bs, dim, 1, seq_len)
+        prediction_logits = self.vocab_projector(
+            prediction_logits)  # (bs, dim, 1, seq_len)
+        prediction_logits = prediction_logits.squeeze(-1).squeeze(
+            -1)  # (bs, dim)
+
+        output = (prediction_logits, ) + dlbrt_output[1:]
+        mlm_loss = None
+
+        return ((mlm_loss, ) + output) if mlm_loss is not None else output
+
+
+class DistilBertForSequenceClassification(
+        modeling_distilbert.DistilBertForSequenceClassification):
+    config_class = DistilBertConfig
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(self, 'distilbert', DistilBertModel(config))
+        setattr(self, 'pre_classifier', nn.Conv2d(config.dim, config.dim, 1))
+        setattr(self, 'classifier', nn.Conv2d(config.dim, config.num_labels,
+                                              1))
+
+    def forward(
+        self,
+        input_ids=None,
+        attention_mask=None,
+        head_mask=None,
+        inputs_embeds=None,
+        labels=None,
+        output_attentions=None,
+        output_hidden_states=None,
+        return_dict=None,
+    ):
+        if labels is not None or self.training:
+            raise NotImplementedError(WARN_MSG_FOR_TRAINING_ATTEMPT)
+
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+        if return_dict:
+            raise ValueError(WARN_MSG_FOR_DICT_RETURN)
+
+        distilbert_output = self.distilbert(
+            input_ids=input_ids,
+            attention_mask=attention_mask,
+            head_mask=head_mask,
+            inputs_embeds=inputs_embeds,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=False,
+        )
+        hidden_state = distilbert_output[0]  # (bs, dim, 1, seq_len)
+        pooled_output = hidden_state[:, :, :, 0:1]  # (bs, dim, 1, 1)
+        pooled_output = self.pre_classifier(pooled_output)  # (bs, dim, 1, 1)
+        pooled_output = nn.ReLU()(pooled_output)  # (bs, dim, 1, 1)
+        logits = self.classifier(pooled_output)  # (bs, num_labels, 1, 1)
+        logits = logits.squeeze(-1).squeeze(-1)  # (bs, num_labels)
+
+        output = (logits, ) + distilbert_output[1:]
+        loss = None
+
+        return ((loss, ) + output) if loss is not None else output
+
+
+class DistilBertForQuestionAnswering(
+        modeling_distilbert.DistilBertForQuestionAnswering):
+    config_class = DistilBertConfig
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(self, 'distilbert', DistilBertModel(config))
+        setattr(self, 'qa_outputs', nn.Conv2d(config.dim, config.num_labels,
+                                              1))
+
+    def forward(
+        self,
+        input_ids=None,
+        attention_mask=None,
+        head_mask=None,
+        inputs_embeds=None,
+        start_positions=None,
+        end_positions=None,
+        output_attentions=None,
+        output_hidden_states=None,
+        return_dict=None,
+    ):
+
+        if self.training or start_positions is not None or end_positions is not None:
+            raise ValueError(WARN_MSG_FOR_TRAINING_ATTEMPT)
+
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+        if return_dict:
+            raise ValueError(WARN_MSG_FOR_DICT_RETURN)
+
+        distilbert_output = self.distilbert(
+            input_ids=input_ids,
+            attention_mask=attention_mask,
+            head_mask=head_mask,
+            inputs_embeds=inputs_embeds,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=False,
+        )
+        hidden_states = distilbert_output[0]  # (bs, dim, 1, max_query_len)
+
+        hidden_states = self.dropout(
+            hidden_states)  # (bs, dim, 1, max_query_len)
+        logits = self.qa_outputs(hidden_states)  # (bs, 2, 1, max_query_len)
+        start_logits, end_logits = logits.split(
+            1, dim=1)  # (bs, 1, 1, max_query_len) * 2
+        start_logits = start_logits.squeeze().contiguous(
+        )  # (bs, max_query_len)
+        end_logits = end_logits.squeeze().contiguous()  # (bs, max_query_len)
+
+        output = (start_logits, end_logits) + distilbert_output[1:]
+        total_loss = None
+
+        return ((total_loss, ) + output) if total_loss is not None else output
+
+
+class DistilBertForTokenClassification(
+        modeling_distilbert.DistilBertForTokenClassification):
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(self, 'distilbert', DistilBertModel(config))
+        setattr(self, 'classifier',
+                nn.Conv2d(config.hidden_size, config.num_labels, 1))
+
+    def forward(
+        self,
+        input_ids=None,
+        attention_mask=None,
+        head_mask=None,
+        inputs_embeds=None,
+        labels=None,
+        output_attentions=None,
+        output_hidden_states=None,
+        return_dict=None,
+    ):
+        if self.training or labels is not None:
+            raise ValueError(WARN_MSG_FOR_TRAINING_ATTEMPT)
+
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+        if return_dict:
+            raise ValueError(WARN_MSG_FOR_DICT_RETURN)
+
+        outputs = self.distilbert(
+            input_ids,
+            attention_mask=attention_mask,
+            head_mask=head_mask,
+            inputs_embeds=inputs_embeds,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=False,
+        )
+
+        sequence_output = outputs[0]  # (bs, dim, 1, seq_len)
+        logits = self.classifier(
+            sequence_output)  # (bs, num_labels, 1, seq_len)
+        logits = logits.squeeze(2).transpose(1, 2)  # (bs, seq_len, num_labels)
+
+        output = (logits, ) + outputs[1:]
+        loss = None
+        return ((loss, ) + output) if loss is not None else output
+
+
+class DistilBertForMultipleChoice(
+        modeling_distilbert.DistilBertForMultipleChoice):
+    config_class = DistilBertConfig
+
+    def __init__(self, config):
+        super().__init__(config)
+        setattr(self, 'distilbert', DistilBertModel(config))
+        setattr(self, 'pre_classifier', nn.Conv2d(config.dim, config.dim, 1))
+        setattr(self, 'classifier', nn.Conv2d(config.dim, 1, 1))
+
+    def forward(
+        self,
+        input_ids=None,
+        attention_mask=None,
+        head_mask=None,
+        inputs_embeds=None,
+        labels=None,
+        output_attentions=None,
+        output_hidden_states=None,
+        return_dict=None,
+    ):
+        if self.training or labels is not None:
+            raise ValueError(WARN_MSG_FOR_TRAINING_ATTEMPT)
+
+        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
+        if return_dict:
+            raise ValueError(WARN_MSG_FOR_DICT_RETURN)
+
+        num_choices = input_ids.shape[
+            1] if input_ids is not None else inputs_embeds.shape[1]
+
+        input_ids = input_ids.view(
+            -1, input_ids.size(-1)) if input_ids is not None else None
+        attention_mask = attention_mask.view(
+            -1,
+            attention_mask.size(-1)) if attention_mask is not None else None
+        inputs_embeds = (inputs_embeds.view(-1, inputs_embeds.size(-2),
+                                            inputs_embeds.size(-1))
+                         if inputs_embeds is not None else None)
+
+        outputs = self.distilbert(
+            input_ids,
+            attention_mask=attention_mask,
+            head_mask=head_mask,
+            inputs_embeds=inputs_embeds,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+            return_dict=False,
+        )
+
+        hidden_state = outputs[0]  # (bs * num_choices, dim, 1, seq_len)
+        pooled_output = hidden_state[:, :, :,
+                                     0:1]  # (bs * num_choices, dim, 1, 1)
+        pooled_output = self.pre_classifier(
+            pooled_output)  # (bs * num_choices, dim, 1, 1)
+        pooled_output = nn.ReLU()(
+            pooled_output)  # (bs * num_choices, dim, 1, 1)
+        logits = self.classifier(pooled_output)  # (bs * num_choices, 1, 1, 1)
+        logits = logits.squeeze()  # (bs * num_choices)
+
+        reshaped_logits = logits.view(-1, num_choices)  # (bs, num_choices)
+
+        output = (reshaped_logits, ) + outputs[1:]
+        loss = None
+
+        return ((loss, ) + output) if loss is not None else output
+
+
+def linear_to_conv2d_map(state_dict, prefix, local_metadata, strict,
+                         missing_keys, unexpected_keys, error_msgs):
+    """ Unsqueeze twice to map nn.Linear weights to nn.Conv2d weights
+    """
+    for k in state_dict:
+        is_internal_proj = all(substr in k for substr in ['lin', '.weight'])
+        is_output_proj = all(substr in k
+                             for substr in ['classifier', '.weight'])
+        if is_internal_proj or is_output_proj:
+            if len(state_dict[k].shape) == 2:
+                state_dict[k] = state_dict[k][:, :, None, None]

pytorch_model.bin

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:f1200fcc3f752c222525b7740abcd87f3aa26a12cd5d5589cf32763458eb9958
+size 267853297