Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!mcvax!ukc!eagle!icdoc!mjd From: mjd@doc.ic.ac.uk (Martin J Davies) Newsgroups: comp.sys.nsc.32k Subject: Re: cxp/rxp instructions Message-ID: <486@ivax.doc.ic.ac.uk> Date: Sun, 19-Jul-87 08:41:33 EDT Article-I.D.: ivax.486 Posted: Sun Jul 19 08:41:33 1987 Date-Received: Fri, 24-Jul-87 01:43:58 EDT References: <1439@tekchips.TEK.COM> Reply-To: winterbo@kcl-cs.UUCP Organization: Dept. of Computing, Imperial College, London, UK. Lines: 16 Keywords: Shared libraries > >>1) What good are the cxp/rxp instructions?... >>The reason I ask is that evern cxp/rxp causes the 32xxx to read >>from the mod table and I can see this as slowing things down A LOT. > >These instructions support shared libraries. Yes, they are somewhat slower than jsr/ret, but they are MUCH faster than doing shared library calls in software! I have implemented shared 'C' libraries on a 32016 machine running my own multi-user/multitasking o/s. I started using the RXP/CXP instructions and this went quite well but there was a speed penalty. I found it much faster to dynamicly link the library calls using an interrupt linkage handler. How this could be applied to unix I am not sure, but modules do seem to use a noticable amount of cpu time. Posted on for P.Winterbottom Kings College London (Gemini Project)