Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!thumper!ulysses!andante!princeton!udel!gatech!ncar!ames!pasteur!ucbvax!agate!eos!labrea!sri-unix!garth!smryan From: smryan@garth.UUCP Newsgroups: comp.lang.c Subject: Re: volatile Message-ID: <673@garth.UUCP> Date: 20 May 88 21:21:21 GMT References: <20345@pyramid.pyramid.com> <502@wsccs.UUCP> <51431@sun.uucp> <659@garth.UUCP> <11566@mimsy.UUCP> Reply-To: smryan@garth.UUCP (Steven Ryan) Organization: INTERGRAPH (APD) -- Palo Alto, CA Lines: 15 Posted: Fri May 20 17:21:21 1988 Enormously expensive refers quadratic, cubic, quadric, or higher order time. Best possible optimisation uses exponential time. (There are few transistive closures involved, graph colourring, et cetera.) What is involved is spending a few days to compile a large system. Some of us have customers who notice if compilation times increases by a millsecond. Also, please do not assume the Church-Turing Hypothesis. The point being, do not expect magic from a compiler. It can provide at best linear improvement. And like everything else in life, the more you put into the more you get out. The less you put in, the less you get out. It's up to you decide if the effort is worthwhile.