Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!davecb From: davecb@yunexus.YorkU.CA (David Collier-Brown) Newsgroups: comp.arch Subject: Re: Is handling off-alignment important? Message-ID: <13711@yunexus.YorkU.CA> Date: 10 Aug 90 13:40:03 GMT References: <104037@convex.convex.com> <8840014@hpfcso.HP.COM> <2357@crdos1.crd.ge.COM> <25900@mimsy.umd.edu> <2392@crdos1.crd.ge.COM> <1990Aug8.212255.3555@zoo.toronto.edu> Organization: York U. Computing Services Lines: 21 In article mcgrath@homer.Berkeley.EDU (Roland McGrath) writes: | On machines that "don't handle misaligned accesses", what do they do when one | happens anyway?... henry@zoo.toronto.edu (Henry Spencer) writes: | Mostly they trap. There are probably one or two design groups that were | foolish enough to just ignore the low bits. Ah yes, many older mainframes... I remember DPS-8s with affection, but not for all the decisions they made. A doubleword register load from an odd address used the floor(address), causing an optimization that used double loads to load the wrong two variables. **MY** that was hard to spot. --dave -- David Collier-Brown, | davecb@Nexus.YorkU.CA, ...!yunexus!davecb or 72 Abitibi Ave., | {toronto area...}lethe!dave Willowdale, Ontario, | "And the next 8 man-months came up like CANADA. 416-223-8968 | thunder across the bay" --david kipling