Operation interfaces, as the name suggests, are those registered at the
Operation level. These interfaces provide an opaque view into derived
operations, by providing a virtual interface that must be implemented. As an
example, the Linalg dialect implements an interface LinalgOp that provides
general queries about some of the dialects library operations. These queries may
provide things like: the number of parallel loops, the number of inputs and
outputs, etc.
Operation interfaces are defined by overriding the CRTP base class OpInterface.
This class takes as a template parameter, a `Traits` class that defines a
Concept and a Model class. These classes provide an implementation of
concept-based polymorphism, where the Concept defines a set of virtual methods
that are overridden by the Model that is templated on the concrete operation
type. It is important to note that these classes should be pure in that they
contain no non-static data members.
PiperOrigin-RevId: 264218741
Dialect interfaces are virtual apis registered to a specific dialect instance. Dialect interfaces are generally useful for transformation passes, or analyses, that want to opaquely operate on operations within a given dialect. These interfaces generally involve wide coverage over the entire dialect.
A dialect interface can be defined by inheriting from the CRTP base class DialectInterfaceBase::Base. This class provides the necessary utilities for registering an interface with the dialect so that it can be looked up later. Dialects overriding an interface may register an instance via 'Dialect::addInterfaces'. This API works very similarly to the respective addOperations/addTypes/etc. This will allow for a transformation/utility to later query the interface from an opaque dialect instance via 'getInterface<T>'.
A utility class 'DialectInterfaceCollection' is also provided that will collect all of the dialects that implement a specific interface within a given module. This allows for simplifying the API of interface lookups.
PiperOrigin-RevId: 263489015
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