Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!decwrl!turtleva!ken From: ken@turtleva.UUCP (Ken Turkowski) Newsgroups: net.lang.c Subject: Re: Must useless expressions be evaluated? Message-ID: <237@turtleva.UUCP> Date: Fri, 14-Oct-83 03:11:38 EDT Article-I.D.: turtleva.237 Posted: Fri Oct 14 03:11:38 1983 Date-Received: Sat, 15-Oct-83 04:55:27 EDT References: bbncca.187 Lines: 12 Another C compiler implementation issue is whether to do computations in shorts when the destination and all the operands are shorts. How about multiplying two shorts giving a long, without converting the shorts to longs and using lmul? Testing bits by using the bit test instruction instead of ANDing? This last one may be an optimizer problem, but the first two are related to K&R's assertion that all computations be done in ints, or that to get a long result, at least one of the operands must be long. Ken Turkowski CADLINC, Palo Alto {decwrl,amd70}!turtlevax!ken