List of Core ops

Not currently a comprehensive list.

More about Core Ops

More about Core Ops

An Op’s primary role is to function as a node in a ddirected acyclic computation graph.

Core ops are ops that are available and generally useful to all framework bridges and that can be compiled by all transformers. A framework bridge may define framework-specific ops to simplify graph construction, provided that the bridge can enable every transformer to replace all such ops with equivalent clusters or subgraphs composed of core ops. In a similar manner, transformers may define transformer-specific ops to represent kernels or other intermediate operations.

The input and output ports of ops are any of the functions which work with Output<Node>/Input<Node>. Previous functions that worked at the level of ops are deprecated, like:

Node::get_element_type()

as it does not take any input. This function has been replaced with new functions like:

Node::get_output_element_type(index)

where there is no ambiguity.

If a framework supports extending the set of ops it offers, a bridge may even expose transformer-specific ops to the framework user.

Operations Available in the nGraph IR

Operations Available in the nGraph IR

Important

Our design philosophy is that the graph is not a script for running kernels; rather, our compilation will match ops to appropriate kernels for the backend(s) in use. Thus, we expect that adding of new Core ops should be infrequent and that most functionality instead gets added with new functions that build sub-graphs from existing core ops.

It is easiest to define a new op by adapting an existing op. Some of the tasks that must be performed are:

  • Op constructor:
    • Checking type-consistency of arguments
    • Specifying the result type for a call
  • Serializer/Deserializer
  • Transformer handlers:
    • Interpreter (reference) implementation of behavior. The implementation should favor clarity over efficiency.