Abstract: Register renaming as contemplated by this invention allows processor hardware to use a larger set of registers than the architected registers visible to the compiler. This larger set of registers is called the physical register file. Thus, dynamically renaming every compiler-suggested architected register to a microarchitecture-specific physical register, allows the processor to overcome name dependencies and the hazards (pipeline slowdowns) induced by name dependencies. The invention here described differs from prior renaming techniques in that it extracts significant benefit from renaming with a fraction of the number of physical registers previously used for this process. The invention therefore also simplifies the logic involved in supporting the use of the physical registers.

Abstract: Disclosed is a split computer system that includes a first housing coupled to a second housing with a multi-conductor cable. The first housing includes a first direct access storage device (DASD) having an opening for receiving a removable storage medium. The second housing is separate from the first housing and includes a central processing unit (CPU) coupled to a local bus and an expansion bus, a non-volatile storage device coupled to the local bus, a second DASD coupled to the local bus and a power supply. The system further includes first and second DASD controllers coupled to the first and second DASDs respectively. The cable has one end coupled to the first housing and another end coupled to the second housing for electrically connecting devices in the first housing to devices in the second housing. The second housing has a first interface coupled to the expansion bus and the cable. The first housing also includes a second interface coupled to the cable and the first DASD.