Activity masking with mask context of SIMD processors

摘要

Disclosed is a masking technique for a SIMD processor (10) which is capable of masking a plurality of individual machine operations within a single instruction incorporating a plurality of operations. To accomplish this each different machine operation within the instruction includes a number of masking bits which address a specific location in a mask register (60). The mask register (60) includes a mask bit bank (62). The mask location selected within the mask register (60) is bit-wise ANDed with a mask context bit (66) in order to establish whether the processing element will be enabled or disabled for a particular conditional sub-routine which is called. One of the bit locations in the mask bit bank (60) is a hard-wired unconditional bit which overrides the mask context bit (66) in order to enable the processing elements in special situations. In addition, a scalar mask bit is provided to facilitate scalar processing. By this operation, instructional parallelism can be incorporated in order to increase through-put of the processor.