title: TensorFlow Operator Source Code
body: <p>I'm trying to find the source code for TensorFlow's low level linear-algebra and matrix arithmetic operators for execution on CPU. For example, where is the actual implementation of <code>tf.add()</code> for execution on a CPU? As far as I know, most linear algebra operators are actually implemented by Eigen, but I'd like to know what Eigen functions specifically are being called.</p>
  
  <p>I've tried tracing back from the high-level API, but this is difficult as there are a lot of steps between placing an operator on the graph, and the actual execution of the operator by the TF runtime.</p>