Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 beta 3/9/83; site encore.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!panda!talcott!encore!ptw From: ptw@encore.UUCP (P. Tucker Withington) Newsgroups: net.lang.c Subject: Re: How does one construct a mask for the MS bit? Message-ID: <177@encore.UUCP> Date: Mon, 4-Mar-85 12:03:47 EST Article-I.D.: encore.177 Posted: Mon Mar 4 12:03:47 1985 Date-Received: Wed, 6-Mar-85 03:04:31 EST References: <8849@brl-tgr.ARPA> Reply-To: ptw@encore.UUCP (P. Tucker Withington) Organization: Encore Computer Corp., Wellesley Hills, MA Lines: 13 Summary: >> This would require generation of a mask for the most significant bit It should be easy to make a constant that masks a machine's "high" bit, but as I mentioned a while back, ~(~(unsigned)0>>1) croaks pcc in a static declaration; apparently because it does not know how to simplify casts in a constant. (It works fine as auto or in an expression, but then you're doing unnecessary work at run time, especially if you made it a #define.) The only feedback I got was that you "should" be allowed to have casts in a constant; that they were "accidentally" left out of K&R... o.o --tucker ~