Three extensions to register integration

Register integration (or just integration) is a register renaming discipline that implements instruction reuse via physical register sharing. Initially developed to perform squash reuse, the integration mechanism is a powerful reuse tool that can exploit more reuse scenarios. In this paper, we describe three extensions to the initial integration mechanism that expand its applicability and boost its performance impact. First, we extend squash reuse to general reuse. Whereas squash reuse maintains the superscalar concept of an instruction instance “owning” its output physical register, we allow multiple instructions to simultaneously and seamlessly share a single physical register. Next, we replace the PC-indexing scheme used by squash reuse with an opcode-based indexing scheme that exposes more integration opportunities. Finally, we introduce an extension called reverse integration in which we speculatively create integration entries for the inverses of operations—for instance, w...

• Type: Conference
• Year: 2002
• Where: MICRO
• Authors: Vlad Petric, Anne Bracy, Amir Roth
• Keywords: Hardware, MICRO 2002, Physical Register, Reverse Integration, Squash Reuse