Method for register renaming by copying a 32 bits instruction directly or indirectly to a 64 bits instruction

US6237076A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Ute Gaertner · Schenefeld, DE
• Klaus J. Getzlaff · Schenefeld, DE
• Oliver Laub · Leinfelden, DE
• Erwin Pfeffer · Eppelheim, DE

Key dates

• Filing date: Aug 28, 1998
• Grant date: May 22, 2001
• Expiry date: Aug 28, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F9/384
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A method and system for renaming registers of said system is proposed in which mixed instruction sets, e.g. 32 bit and 64 bit instructions are carried out concurrently in one program. In case of an instruction sequence of a preceding 64 bit instruction and one or more 32 bit instructions to be executed in-order after the 64 bit instruction and where the 32 bit instructions having a data dependence to the preceding 64 bit instruction, said rest of the register range changed by the preceding 64 bit instruction is copied to the corresponding location in a target register of the succeeding 32 bit instruction, at least if the same logical register is specified by the 32 bit instruction as it was specified by the preceding 64 bit instruction. The copy source is addressed by the register number and hold in a list (28).