Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site gatech.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!mhuxn!mhuxj!mhuxr!ulysses!gatech!jeff From: jeff@gatech.UUCP (Jeff Lee) Newsgroups: net.unix-wizards,net.lang Subject: Re: smart compilers Message-ID: <11496@gatech.UUCP> Date: Fri, 28-Dec-84 15:02:06 EST Article-I.D.: gatech.11496 Posted: Fri Dec 28 15:02:06 1984 Date-Received: Sat, 29-Dec-84 05:47:33 EST References: <6599@brl-tgr.ARPA> <979@opus.UUCP> <6831@watdaisy.UUCP> Organization: School of ICS, Georgia Institute of Technology, Atlanta Lines: 24 Xref: watmath net.unix-wizards:11265 net.lang:1177 > It is usually necessary for optimizations to break certain obscure points > that conform to the language definition, e.g. which order STATEMENTS are > executed in so that code can be moved out of loops. Many useful optimizations > cannot be done when more than 99.9% of the language definition must be > respected. > > In turn, this is the reason that optimizations must be optional. This is a truly incredible statement. I'm sure we can come up with many more optimizations that work real well if we only respect 99% of the language definition, but how useful are those "optimizations". It seems to me that when your optimizer gets finished with your code, it is no longer compiling FORTRAN, Pascal, C, etc... but some dialect that doesn't do what you intended for it to do. I don't want any compiler (and optimizer) that doesn't "respect" all of the language definition. That is simply begging and pleading for trouble. Jeff Lee CSNet: Jeff @ GATech ARPA: Jeff.GATech @ CSNet-Relay uucp: ...!{akgua,allegra,rlgvax,sb1,unmvax,ulysses,ut-sally}!gatech!jeff -- Jeff Lee CSNet: Jeff @ GATech ARPA: Jeff.GATech @ CSNet-Relay uucp: ...!{akgua,allegra,rlgvax,sb1,unmvax,ulysses,ut-sally}!gatech!jeff