Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!cmcl2!lanl!cochiti.lanl.gov!jlg
From: jlg@cochiti.lanl.gov (Jim Giles)
Newsgroups: comp.lang.c
Subject: Re: low level optimization
Message-ID: <22356@lanl.gov>
Date: 23 Apr 91 15:13:50 GMT
References: <21660@lanl.gov> <1991Apr17.225944.15261@zoo.toronto.edu> <1991Apr18.190403.29049@Think.COM> <21846@lanl.gov> <3247@ksr.com>
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Organization: Los Alamos National Laboratory
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>> And, as I said, if the standard says you _may_
>> do something, the implementation _must_ permit you to do it.
>
> If a compilation system waits until it knows where all the source code is
> to perform code generation, what is the user not being permitted to do?
> Get slow code?  No thanks!

If the compilation system waits until it knows where all the source
code is to perform code generation, it's got a long wait coming.  Many
vendors don't distribute source code.  Your compilation system is 
_never_ going to know where the vendor's source code is.  What you are
not permitting the user to do is one of the very things that separate
compilation is _for_ - vendor distribution of _object_ code.  If your
compiler/language requires source to get fast code, you should think
about changing languages.

J. Giles