【Hackathon 6th No.1】Add AdaptiveLogSoftmaxWithLoss API to Paddle -part

python/paddle/nn/__init__.py

@@ -86,6 +86,7 @@
 from .layer.distance import PairwiseDistance
 from .layer.layers import Layer
 from .layer.loss import (
+    AdaptiveLogSoftmaxWithLoss,
     BCELoss,
     BCEWithLogitsLoss,
     CosineEmbeddingLoss,
@@ -295,6 +296,7 @@
     'TripletMarginLoss',
     'SoftMarginLoss',
     'GaussianNLLLoss',
+    'AdaptiveLogSoftmaxWithLoss',
     'Unflatten',
     'FractionalMaxPool2D',
     'FractionalMaxPool3D',

python/paddle/nn/functional/__init__.py

@@ -94,6 +94,7 @@
 )
 from .input import embedding, one_hot
 from .loss import (
+    adaptive_log_softmax_with_loss,
     binary_cross_entropy,
     binary_cross_entropy_with_logits,
     cosine_embedding_loss,
@@ -276,6 +277,7 @@
     'rrelu',
     'triplet_margin_with_distance_loss',
     'triplet_margin_loss',
+    'adaptive_log_softmax_with_loss',
     'multi_margin_loss',
     'soft_margin_loss',
     'gaussian_nll_loss',

python/paddle/nn/functional/loss.py

@@ -4285,3 +4285,154 @@ def gaussian_nll_loss(
         return paddle.sum(loss, name=name)
     elif reduction == 'none':
         return loss
+
+
+def adaptive_log_softmax_with_loss(
+    input, label, head_weight, tail_weights, cutoffs, head_bias=None, name=None
+):
+    r"""Compute adaptive logsoftmax result and negative log likelihood between ``input`` and ``label``.
+    Parameter ``head``, ``tail_weights``, ``cutoffs`` are inner members of AdaptiveLogSoftmaxWithLoss
+    Please refer to :ref:`_cn_api_paddle_nn_AdaptiveLogSoftmaxWithLoss`.
+
+    Args:
+        input (Tensor): Input tensor, the data type should be float32 or float64.
+        label (Tensor): Label tensor, the data type should be float32 or float64.
+        head_weight (Tensor): weight tensor for linear computation, the data type should be float32 or float64, the shape should be [input.shape[1], shortlist_size + n_clusters], where shortlist_size is the first element in the cutoffs list, and n_clusters is the length of the cutoffs list minus 1.
+        tail_weights (list[Tensor]): weight tensor list for linear computation, the data type should be float32 or float64. The number of elements in the tail_weights depends on the value of the n_clusters, and each element contains the weights of two linear layers, their dimensions are [input.shape[1], hsz] and [hsz, osz], where hsz is the number of input features in_features divided by div_value to the power (i + 1), where i is the cyclic variable, from 0 to n_clusters - 1, and osz is the (i + 1) The difference between the cutoff and the ith cutoff.
+        cutoffs (Sequence): Cutoffs used to assign targets to their buckets.
+        head_bias (Tensor, optional): bias tensor for linear computation, the data type should be float32 or float64.
+        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
+
+    Returns:
+        output (Tensor): The tensor sotring adaptive logsoftmax result, the shape of output is [N]
+        loss (Tensor): The tensor variable storing the adaptive_log_softmax_loss of input and label.
+
+    Examples::
+        .. code-block:: python
+
+            >>> import paddle
+            >>> import paddle.nn.functional as F
+
+            >>> paddle.seed(2024)
+            >>> input = paddle.randn([3, 5], dtype=paddle.float32)
+            >>> head_weight = paddle.randn([5, 3], dtype=paddle.float32)
+            >>> head_bias = paddle.randn([3], dtype=paddle.float32)
+            >>> tail_weights = []
+            >>> tail_weights.append(paddle.randn([5, 2], dtype=paddle.float32))
+            >>> tail_weights.append(paddle.randn([2, 1], dtype=paddle.float32))
+            >>> out, loss = F.adaptive_log_softmax_with_loss(input, paddle.full((3,), 1, dtype='int64'), head_weight, tail_weights, cutoffs=[2], head_bias=head_bias)
+            >>> print(out)
+            Tensor(shape=[3], dtype=float32, place=Place(cpu), stop_gradient=True,
+            [-0.99842924, -2.27753878, -0.16740258])
+            >>> print(loss)
+            Tensor(shape=[], dtype=float32, place=Place(cpu), stop_gradient=True,
+            1.14779019)
+    """
+    targt_dim = label.dim()
+
+    if targt_dim == 1:
+        if input.shape[0] != label.shape[0]:
+            raise ValueError(
+                'Input and label should have the same size '
+                'in the batch dimension.'
+            )
+        if input.dim() != 2:
+            raise ValueError(
+                '1D label tensor expects 2D input tensors, '
+                'but found inputs with size',
+                input.shape,
+            )
+    elif targt_dim == 0:
+        if input.dim() != 1:
+            raise ValueError(
+                '0D label tensor expects 1D input tensors, '
+                'but found inputs with size',
+                input.shape,
+            )
+    else:
+        raise ValueError(
+            '0D or 1D label tensor expected, ' 'multi-label not supported'
+        )
+
+    is_batched = targt_dim > 0
+    input = input if is_batched else input.unsqueeze(0)
+    label = label if is_batched else label.unsqueeze(0)
+
+    used_rows = 0
+    batch_size = label.shape[0]
+
+    output = paddle.zeros([batch_size], dtype=input.dtype)
+    gather_inds = paddle.empty([batch_size], dtype=label.dtype)
+
+    cutoff_values = [0] + cutoffs
+    for i in range(len(cutoff_values) - 1):
+        low_idx = cutoff_values[i]
+        high_idx = cutoff_values[i + 1]
+
+        label_mask = (label >= low_idx) & (label < high_idx)
+        row_indices = label_mask.nonzero().squeeze()
+
+        if row_indices.numel() == 0:
+            continue
+
+        if i == 0:
+            scatter_output = paddle.scatter_nd(
+                row_indices.unsqueeze(1),
+                label.masked_select(label_mask),
+                gather_inds.shape,
+            )
+            gather_inds = scatter_output
+        else:
+            relative_label = label[label_mask] - low_idx
+            input_subset = input.index_select(row_indices, axis=0)
+
+            cluster_output = paddle.nn.functional.linear(
+                x=input_subset, weight=tail_weights[i - 1][0]
+            )
+            cluster_output = paddle.nn.functional.linear(
+                x=cluster_output, weight=tail_weights[i - 1][1]
+            )
+
+            cluster_index = cutoffs[0] + i - 1
+
+            gather_inds = paddle.index_fill(
+                gather_inds, row_indices, 0, cluster_index
+            )
+
+            cluster_logprob = paddle.nn.functional.log_softmax(
+                cluster_output, axis=1
+            )
+
+            local_logprob = paddle.take_along_axis(
+                cluster_logprob, relative_label.unsqueeze(1), axis=1
+            )
+            scatter_output = paddle.scatter_nd(
+                row_indices.unsqueeze(1), local_logprob.squeeze(1), output.shape
+            )
+            output = (
+                output * (scatter_output == 0).astype('float32')
+                + scatter_output
+            )
+
+        used_rows += row_indices.numel()
+
+    if used_rows != batch_size:
+        raise ValueError(
+            f"label values should be in [0, n_classes - 1], "
+            f"but values in range [{label.min().item()}, {label.max().item()}] "
+            "were found. "
+        )
+
+    head_output = paddle.nn.functional.linear(
+        x=input, weight=head_weight, bias=head_bias
+    )
+    head_logprob = paddle.nn.functional.log_softmax(head_output, axis=1)
+    output += paddle.take_along_axis(
+        head_logprob, gather_inds.unsqueeze(1), axis=1
+    ).squeeze()
+    loss = (-output).mean()
+
+    if not is_batched:
+        output = output.squeeze(0)
+
+    return output, loss

python/paddle/nn/layer/__init__.py

@@ -60,6 +60,7 @@
 from .distance import PairwiseDistance  # noqa: F401
 from .layers import Layer  # noqa: F401
 from .loss import (  # noqa: F401
+    AdaptiveLogSoftmaxWithLoss,
     BCELoss,
     BCEWithLogitsLoss,
     CrossEntropyLoss,