The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 2001
Filed:
Jun. 02, 1999
Ravindra K. Nair, Briarcliff Manor, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and apparatus for prefetching superblocks in a computer processing system having a fetch mechanism for fetching instructions for execution includes the step of controlling the fetch mechanism to begin fetching at a starting address of a current superblock. A superblock includes a set of instructions in consecutive address locations terminated by a branch instruction known to have been taken. A Superblock Target Buffer (STB) is supplied with the starting address of the current superblock. The STB has a plurality of entries each indexed by a starting address of a superblock and including a run length of the superblock and a target address of the terminating branch of the superblock. The run length corresponds to the sum of a length of the terminating branch and the difference between a starting address of the terminating branch of the superblock and the starting address of the superblock. It is then determined whether or not the starting address of the current superblock supplied to the STB matches a starting address indexing an STB entry. A starting address of a next sequential superblock is determined by summing the starting address of the current superblock and the run length specified in the STB entry, when the starting address of the current superblock supplied to the STB matches the starting address indexing the STB entry. The fetch mechanism is controlled to end fetching at the starting address of the next sequential superblock.