Function MaximumMinimumGradCommon

tensorflow/cc/gradients/math_grad.cc:545–559

MaximumMinimumGradCommon adds shared ops to calculate gradients for the binary Maximum and Minimum ops.

// MaximumMinimumGradCommon adds shared ops to calculate gradients for
// the binary Maximum and Minimum ops.
Status MaximumMinimumGradCommon(const Scope& scope, const Operation& op,
                                const std::vector<Output>& grad_inputs,
                                std::vector<Output>* grad_outputs,
                                const Output& comparator) {
  // comparator is a boolean tensor, with
  // y = x_1 at points where comparator is true, and x_2 otherwise
  // Therefore
  // dy/dx_1 = 1 where comparator is true, and 0 otherwise.
  // dy/dx_2 = 0 where comparator is true, and 1 otherwise.
  auto grad = grad_inputs[0];
  auto zeros = ZerosLike(scope, grad);
  auto gx_1 = Where3(scope, comparator, grad, zeros);
  auto gx_2 = Where3(scope, comparator, zeros, grad);
  return BinaryGradCommon(scope, op, grad_outputs, gx_1, gx_2);
}

Status MaximumGrad(const Scope& scope, const Operation& op,
                   const std::vector<Output>& grad_inputs,