From: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: pentium
Date: 18 Feb 1997 06:02:16 GMT
Organization: The National Capital FreeNet
Lines: 32
Message-ID: <5ebgl8$lan@freenet-news.carleton.ca>
References: <199702161216 DOT HAA10376 AT delorie DOT com> <Pine DOT HPP DOT 3 DOT 95 DOT 970217133936 DOT 15118A-100000 AT santaka DOT sc-uni DOT ktu DOT lt> <rzqk9o71dzp DOT fsf AT djlvig DOT dl DOT ac DOT uk>
Reply-To: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
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To: djgpp AT delorie DOT com
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Dave Love (d DOT love AT dl DOT ac DOT uk) writes:
>>>>>> "Martynas" == Martynas Kunigelis <algikun AT santaka DOT sc-uni DOT ktu DOT lt> writes:
> 
>  Martynas> Do you mean that pentium optimized code does not run on
>  Martynas> 386/486?
> 
> I don't know about that, but the `pgcc' hacks that I last saw actually
> were even at least somewhat specific to the GCC front end language
> (tough on Fortran, for instance).  I've also been told that they are
> 586-specific and not appropriate (as optimizations) for 686.

686???

> For the brave, a snapshot of the current gcc development version,
> which has (different) [56]86 knowledge can be had from the GNU `win'32
> distribution at ftp.cygnus.com.  [Other front ends than the C-based
> ones may not build against it straight off; G77 won't, anyhow.]

Why not include an option to build a program into a "super-executable"
with three copies of the code in it, and at the start a routine to
autodetect whether you have <586, 586, or 686 and branch to the right
code, which is properly optimised for that chip?
(Of course exe's would be up to three times as big, except for the 200k
startup-code and stub.)


--
    .*.  Where feelings are concerned, answers are rarely simple [GeneDeWeese]
 -()  <  When I go to the theater, I always go straight to the "bag and mix"
    `*'  bulk candy section...because variety is the spice of life... [me]
Paul Derbyshire ao950 AT freenet DOT carleton DOT ca, http://chat.carleton.ca/~pderbysh