Newsgroups: comp.lang.c
Path: utzoo!utgpu!watserv1!watmath!tolstoy.waterloo.edu!mhcoffin
From: mhcoffin@tolstoy.waterloo.edu (Michael Coffin)
Subject: Re: low level optimization
Message-ID: <1991Apr18.124836.5686@watmath.waterloo.edu>
Sender: news@watmath.waterloo.edu (News Owner)
Organization: University of Waterloo
References: <21660@lanl.gov> <1991Apr17.190243.24691@watmath.waterloo.edu> <21703@lanl.gov>
Date: Thu, 18 Apr 1991 12:48:36 GMT
Lines: 15

In article <21703@lanl.gov> jlg@cochiti.lanl.gov (Jim Giles) writes:
>For a language which requires
>separate compilation, _NO_OTHER_INFORMATION_ is known about an
>external procedure.  The reason is that _all_ other characteristics
>of an external procedure are allowed to _change_ without the need to
>recompile any uses of that procedure.

The C standard doesn't say Thou Must Compile Separately.  It says that
the meaning of the program---roughly speaking, the output obtained by
running the program---doesn't depend on information gleaned from
intermodule analysis.  Nothing in the standard says that a compiler
can't take advantage of all available information to produce good
code.

-mike