International Business Machines Corporation

James Albert Van Norstrand, Jr

Balaram Sinharoy

Christopher Michael Abernathy

William Elton Burky

Richard William Doing

Jeffrey Richard Summers

Albert Thomas Williams

Kevin Neal Magil

Disclosed are a method and a system for grouping processor instructions for execution by a processor, where the group of processor instructions includes at least two branch processor instructions. In one or more embodiments, an instruction buffer can decouple an instruction fetch operation from an instruction decode operation by storing fetched processor instructions in the instruction buffer until the fetched processor instructions are ready to be decoded. Group formation can involve removing processor instructions from the instruction buffer and routing the processor instruction to latches that convey the processor instructions to decoders. Processor instructions that are removed from instruction buffer in a single clock cycle can be called a group of processor instructions. In one or more embodiments, the first instruction in the group must be the oldest instruction in the instruction buffer and instructions must be removed from the instruction buffer ordered from oldest to youngest.

Group formation with multiple taken branches per group

A method and processor for performing on-demand scratch register reallocation by dynamically adjusting the number of scratch registers from within the pool of rename registers includes initially allocating from a set of physical registers one or more architected registers and a pool of one or more rename registers and allocating from the pool of rename registers an initial number of scratch registers for storing microcode operands. In response to detecting that a fetched instruction requires an additional scratch register beyond the initial number, a selected physical register is reallocated from among the pool of rename registers as the additional scratch register, and a flag is set to indicate the rename register is allocated as the additional scratch register. In response to determining that the additional scratch register is no longer needed, the additional scratch register is deallocated and the flag is reset, such that the selected physical register returns to the pool of rename registers.

Method and system for on-demand scratch register renaming

Growing community of inventors

Round Rock, TX, United States of America

James Albert Van Norstrand, Jr