Path: ...!weretis.net!feeder9.news.weretis.net!i2pn.org!i2pn2.org!.POSTED!not-for-mail From: mitchalsup@aol.com (MitchAlsup1) Newsgroups: comp.arch Subject: Re: except what, is Vax addressing sane today Date: Sun, 22 Sep 2024 18:40:31 +0000 Organization: Rocksolid Light Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Info: i2pn2.org; logging-data="3036965"; mail-complaints-to="usenet@i2pn2.org"; posting-account="65wTazMNTleAJDh/pRqmKE7ADni/0wesT78+pyiDW8A"; User-Agent: Rocksolid Light X-Rslight-Site: $2y$10$xEk4ba9o6tRFSg.JdlmrJ.sCik7wBbg5298l8jVeJCXLzvqwsmo/O X-Spam-Checker-Version: SpamAssassin 4.0.0 X-Rslight-Posting-User: ac58ceb75ea22753186dae54d967fed894c3dce8 Bytes: 2133 Lines: 25 On Sun, 22 Sep 2024 11:30:00 +0000, John Dallman wrote: > In article , > mitchalsup@aol.com (MitchAlsup1) wrote: >> On Sun, 22 Sep 2024 0:14:49 +0000, Chris M. Thomasson wrote: >>> On 9/21/2024 4:29 PM, Lawrence D'Oliveiro wrote: >>>> Aren't branches that are not taken supposed to be fast? >>> Well, they are not taken, so they should be faster... ;^) >> It is NOT the speed, it is the code bloat. > > Yup. Bigger code is always a potential problem, not so much because it > takes up RAM nowadays, but because it takes up memory bandwidth and > cache > space. Using up cache space is always bad, because bigger caches are > slower, and instructions seem naturally smaller than cache blocks. > > Wanting smaller code isn't an argument against RISC, but an argument > against poorly optimised ISA design. Variable-length CISC makes it > easier to get smaller average instruction sizes but has other drawbacks. Variable length RISC makes it easier, too. > For the stuff I work, on ARM64 code is consistently smaller than x86-64, > although the factor varies by platform. > > John