Subject: Re: Floating Point speed in Common Lisp From: Erik Naggum <clerik@naggum.no> Date: 1998/03/29 Newsgroups: comp.lang.lisp Message-ID: <3100173493999671@naggum.no> * Andi Kleen | How can bigloo or Stalin produce faster code than C when they both | compile into C? the same way some C compilers produce faster and better assembly code than humans could do even though they produce assembly code: by going way beyond the mental limitations of the human mind in the code produced, such as the number of "open issues" that can be dealt with. for the most part, this is a purely mechanical limitation, so if a programmer can make another program (such as a compiler) juggle the open issues for him, he can deal with more of them. since C is an amazingly stupid language, the number of open issues for even an excellent C programmer are strictly limited to a small constant number. (the human consciousness is reported to be able to deal with 7 simultaneously open issues, which very from all concrete, like something to watch out for, to very abstract, like a free variable. most programming languages do not optimize for the use of these "slots" in the human psyche, and so can vary greatly in how many are required at any time. compilers, however, do not have to worry about such slots, and can have any number of issues open at a time, and can thus make what would appear to a human being to be highly intelligent conclusions; recall the references to the "sufficiently smart compiler".) #:Erik -- religious cult update in light of new scientific discoveries: "when we cannot go to the comet, the comet must come to us."