Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!houxm!vax135!cornell!uw-beaver!tektronix!hplabs!sri-unix!BLARSON@ecld.#eclnet From: BLARSON@ecld.#eclnet Newsgroups: net.lang.c Subject: Re: advice statement Message-ID: <13035@sri-arpa.UUCP> Date: Fri, 31-Aug-84 07:18:22 EDT Article-I.D.: sri-arpa.13035 Posted: Fri Aug 31 07:18:22 1984 Date-Received: Mon, 3-Sep-84 11:17:52 EDT Lines: 18 From: Bob Larson The Prime 9950 and 9750 are examples of non-RISC pipelined architectures that handle this problem (branch lookahead) by utilizing a special branch cashe with an 80% success rate (according to sales literature). Most programmers could probably not beat this, especially since the branch cashe is updated on the fly. Note that a pipeline architecture can only take the most probable path, so only one bit of the programmers guess would be significant (which path is most probable). The Prime 9950 and 9750, being object code compatible with the rest of the 50 series, have no provision for a programmers guess of the most probable path. Do you have an example of a (commercially produced in quantity) machine that does expect a guess of the most probable path? I feel that this problem is best solved in the machines that need it by additional hardware rather that expecting all programs to be updated to run on it. Bob Larson -------