Maintaining state information

An apparatus comprising:

• a data processing pipeline for processing a sequence of instructions, wherein the data processing pipeline comprises decoder circuitry responsive to receipt of instructions of the sequence of instructions to generate control signals to control the data processing pipeline to perform processing operations;
• and
• extension processing circuitry responsive to identification, by the data processing pipeline, of a delegated task to perform the delegated task asynchronously to the data processing pipeline,
• wherein:
• the extension processing circuitry is configured to maintain extension state information indicative of an execution context of the extension processing circuitry independent of processing state information associated with the data processing pipeline;
• and
• the decoder circuitry is responsive to an extension context restore instruction comprising a storage location identifier, to trigger the extension processing circuitry, in response to an indication that restoration of previous extension state information associated with the previous execution context is required, to load the previous extension state information from a location identified by the storage location identifier.

A method of operating an apparatus comprising a data processing pipeline for processing a sequence of instructions, wherein the data processing pipeline comprises decoder circuitry responsive to receipt of instructions of the sequence of instructions, to generate control signals to control the data processing pipeline to perform processing operations, the method comprising:

• with extension processing circuitry and in response to identification, by the data processing pipeline, of a delegated task, performing the delegated task asynchronously to the data processing pipeline;
• maintaining, using the extension processing circuitry, extension state information indicative of an execution context of the extension processing circuitry independent of processing state information associated with the data processing pipeline;
• and
• with the decoder circuitry, in response to an extension context save instruction comprising a storage location identifier, triggering the extension processing circuitry to perform a context switch from the execution context to a further execution context and, at a point of storing the extension state information, storing the extension state information to a location identified by the storage location identifier.