Browse Prior Art Database

Unencountered Branch Indication

IP.com Disclosure Number: IPCOM000060544D
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Mar-08

Publishing Venue

IBM

Related People

Authors:
Emma, PG Knight, JW Pomerene, JH Rechtschaffen, RN Sparacio, FJ [+details]

Abstract

A method is set forth for reducing the branch penalty when processing branch instructions in a computer. A Branch History Table (BHT) contains entries that are comprised of the pair for addresses of branches that were last observed to have been taken. During prefetching, the BHT is searched to see if an entry exists for which is the same as the fetch address. A "BHT hit" is the event in which such an entry is found, and the consequence of a hit is to redirect prefetching down the path specified by and to notify the instruction decoder that the instruction at is a taken branch.