delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/2001/02/07/15:34:21

From: "Miguel A. Ballicora" <ballicor AT msu DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Function and File ordering and speed optimization
Date: Wed, 07 Feb 2001 15:03:43 -0500
Organization: Michigan State University
Lines: 44
Message-ID: <3A81AA1F.D8D883CB@msu.edu>
References: <3A8049B6 DOT 7C7B7BB1 AT msu DOT edu> <95pk8j$ft4$1 AT nets3 DOT rz DOT RWTH-Aachen DOT DE>
NNTP-Posting-Host: padmanab-51.user.msu.edu
Mime-Version: 1.0
X-Mailer: Mozilla 4.7 [en] (WinNT; I)
X-Accept-Language: en,pdf
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com


Hans-Bernhard Broeker wrote:

[snip]

>
> > Do I have to place the function definitions in the same order in one
> > file.c when I compile?
>
> If you want to achieve that sorting: yes. The order of .o files in
> your command line would also be important.
>
> > Is djgpp going to follow that sorting?
>
> Yes. The DJGPP linker doesn't reorder objects itself.

Thanks for the answer and the discussion! very instructive to me.
And that is what I needed to know!. I do not know if this kind of
optimization
is going to be useful in my case. Probably not much, but I got curious when I
changed
in RHIDE the name of one of files in the project and I got ~5% reduction in
the the speed.
I renamed the file to the original and I recovered the speed. Apparently,
RHIDE gives
to the compiler and linker the list of files sorted alphabetically, so
renaming files change the function order. I did not play around much with
this, but it looked weird. That is why I thought
that I could optimize the order of the files and functions. When I have time
I will try a little bit
of this. I won't try to sort the whole thing but I will chose the smallest
and hottest functions
the profiler will give me. I won't be a lot of work, I think.
Of course, I have to do other obvious optimizations first, but since speed is
critical to me, I won't
discard anything...

Thanks,
Miguel




- Raw text -


  webmaster     delorie software   privacy  
  Copyright 2019   by DJ Delorie     Updated Jul 2019