SWITCHING MULTI-CONTEXT PROCESSOR AND METHOD OVERCOMING PIPELINE VACANCIES

An instruction executing section supplies an instruction of a certain context to a pipeline and executes the context. When a vacancy of the pipeline is judged, the instruction executing section switches the context to another context which is being executed, thereby simultaneously executing a plurality of contexts. An ID setting section sets a peculiar context ID to each of the plurality of contexts which are simultaneously executed by the instruction executing section. A register renaming section executes a multi-renaming such that a register name which is used when the plurality of contexts are simultaneously executed by the instruction executing section is renamed to a register name CIDi-Rj obtained by adding a designation register name Rj (j=1, 2, 3, . . . , m) of an execution instruction to CIDi as a context ID which was set by an ID setting section and whose context is being executed and the physical register is allocated.