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Reprioritizing STORES With Respect to GUESSED TAKEN I-Fetches to Improve I-Fetching During TAKEN Branch Delays

IP.com Disclosure Number: IPCOM000034325D
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27

Publishing Venue

IBM

Related People

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

Abstract

By reprioritizing STORES from a previous branch-taken-group (BTG), whose putaway falls in a GUESSED-TAKEN interval, the processor design assures that both the taken branch delay is not lengthened and the requisite I-Fetch is interfered with on a minimal basis. The ability to perform the requisite I-Fetching for a BTG is generally limited to the interval between taken branches. Store activity from the previous group can prevent the three initial I-Fetches for the BTG from occurring within the GUESSED-TAKEN interval. With the exception of the dynamics introduced by cache misses and the action and target changes of branches, the inevitability of the I-Fetch-Store interaction is evident. Not only will the store interfere with the I-Fetching, but will continue to do so in a recurrent manner.