COMPOUND INSTRUCTIONS IN A MULTI-THREADED PROCESSOR

A multi-threaded processor determines which threads to execute, switches between execution of threads in dependence on the determination, each thread being coupled to a respective register for storing the state of the thread and used in executing instructions on the thread and includes a further register shared by all the threads. The executing threads use the further register to improve execution performance and prevents the switching of execution to another thread while the internal register is in use.