// computes loss and backprop of the loss with respect to 'features'.
//
// Softmax cross entropy loss is defined as follows:
//
//  loss = Sum(-labels * Log(Exp(features) / Sum(Exp(features)))
//  loss = Sum(-labels * LogSoftmax(features))
//
// Computing gradient of the loss with respect to features gives us,
//
//  backprop = (Exp(features) / Sum(Exp(features))) - labels

      Value scratch2 =
          ApplyReduction(loc, weighted_grad, reduce_dims, &rewriter);

      // x_backprop = y_backprop * (scale * scratch1)
      auto scaled_grad =
          rewriter.create<mhlo::MulOp>(loc, op.getScale(), scratch1);
      x_backprop = rewriter.create<mhlo::MulOp>(
          loc, grad,
          Broadcast1DToFeatureDim(loc, act, scaled_grad, feature_dim,

example, suppose y = f(x) and we wish to apply a custom function g for backprop
such that dx = g(dy). In Python,

```python
with tf.get_default_graph().gradient_override_map(
    {'IdentityN': 'OverrideGradientWithG'}):
  y, _ = identity_n([f(x), x])

@tf.RegisterGradient('OverrideGradientWithG')
def ApplyG(op, dy, _):
  return [None, g(dy)]  # Do not backprop to f(x).
```
  }];

  let arguments = (ins

        *   `tf.compat.v1.nn.fused_batch_norm` backprop to `offset` when
            `is_training=False`
        *   `tf.image.adjust_contrast` forward
        *   `tf.nn.depthwise_conv2d` backprop to `filter` when not using cuDNN
            convolution
        *   `tf.image.resize` with `method=ResizeMethod.NEAREST` backprop
        *   `tf.math.bincount` - TODO: confirm exception added

  let description = [{
    Automatic space to depth transform is done by adding space to depth transform op after host input
    and applying space to depth transform for the first convolution and its backprop filter on TPU.

    For example, original program:

    ```mlir
    module {
      func @while_body {
        %input = "tf.IteratorGetNext"(...) {device = "/CPU:0"}: -> tensor<2x224x224x3xf32>