Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!zaphod.mps.ohio-state.edu!think.com!paperboy!meissner From: meissner@osf.org (Michael Meissner) Newsgroups: comp.lang.misc Subject: Re: Aggressive optimization Message-ID: Date: 11 Nov 90 21:26:07 GMT References: <2060@aber-cs.UUCP> <65592@lanl.gov> <2677@l.cc.purdue.edu> <12175@ganymede.inmos.co.uk> <123@garth.UUCP> Sender: news@OSF.ORG Organization: Open Software Foundation Lines: 31 In-reply-to: smryan@garth.UUCP's message of 6 Nov 90 20:12:12 GMT In article <123@garth.UUCP> smryan@garth.UUCP (Steven Ryan) writes: | Beat me! Whip me! Make me use an optimiser! | | Isn't this kind of silly? Are there really compilers that force people to | use the optimiser or is it optional? If it's optional and you don't want, | don't use. If you can buy a compiler without an optimiser (which is easy), | do so. If nobody wants an optimiser, nobody buys them. If somebody wants | one, why not let them buy it? I once worked on a language (DG/L at Data General), in which it had NO option to turn off the optimizer. It was 9 passes plus a control program that ran in a 64K address space (and no segments to extend the address space), and had some optimizations that the later DG compilers never did, such as doing interprocedural analysis with code motion from internal subroutines to their caller's. I've also found a few cases in finishing GCC ports for the 88k and MIPS, where optimizing the code produced correct code, and not optimizing produced compiler error messages. This is because constraints in the machine description were not quite correct, but the optimizer smoothed things over by putting variables into registers. I personally never compile any code, except test suites, without enabling both debug and 'full' optimization these days, unless I'm using a vendor's PCC derived compiler. -- Michael Meissner email: meissner@osf.org phone: 617-621-8861 Open Software Foundation, 11 Cambridge Center, Cambridge, MA, 02142 Considering the flames and intolerance, shouldn't USENET be spelled ABUSENET?