Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!lll-winken!elroy.jpl.nasa.gov!usc!wuarchive!kuhub.cc.ukans.edu!markv
From: markv@kuhub.cc.ukans.edu
Newsgroups: comp.sys.amiga.programmer
Subject: Re: How are some programs SO DAMN SMALL!
Message-ID: <28077.279c3c3f@kuhub.cc.ukans.edu>
Date: 22 Jan 91 19:21:02 GMT
References: <1991Jan20.210328.18087@hoss.unl.edu>
Organization: University of Kansas Academic Computing Services
Lines: 52

> the result is 4424 bytes, OPTIMIZED and all.  How can a HUGE clock compile
> smaller then a printf statement.

Assembler has a lot to do with it.  A C compiler pulls in a lot of
code for run time support.
  
> What are steps to compile the smallest Lattice code?  Here are the few that I
> know.
>  
> 1)  Use protos and include files whenever possible.
> 2)  Utilize .library calls when possible and don't forget to OPEN it so
>     the pragmas dont go to waste.
> 3)  Try not to use printf and any amiga.lib function for the matter.
> 4)  Compile with -Lvrt -curfist -rr -mat -O -b1 file to create registerized
>     code.

Well, you can cheat quite a bit.  Write all your I/O to use Amiga
system lib funcs.  Rewrite the startup to be bare bones and not pull
in things.  Play with the preprocessor.  I have a file "mystdio.h"
that I include after stdio.h that includes things like:

#define puts(s)	{Write(Output(), s, strlen(s));}

This gets pretty efficient assuming an inline strlen.  Things like
sprintf(), fprintf(), etc (w/o fancy formatting) can be emulated using
RawDoFmt() and Write().  Fopen can be done with things like:

#define "w" MODE_NEWFILE
#define "r" MODE_OLDFILE

#define fopen(f, m);	Open(f, m);

Note that doing things like this you loose the support you get from
the normal C library like buffering, auto file closing, etc.  Modes
like "w+", etc require more work but are possible.

> Can 'C' code get small?  I have a LIST program in the works.  It's 14000
> bytes compared to c:list's 2500.  Assembly must be the only decent way to
> go.
  
See how small it gets if you use AmigaDOS functions like Examine(),
ExNext(), Write()) and system support, RawDoFmt(), etc instead of C
lib functions like printf(), dnext(), etc.
-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mark Gooderum			Only...		\    Good Cheer !!!
Academic Computing Services	       ///	  \___________________________
University of Kansas		     ///  /|         __    _
Bix:	  markgood	      \\\  ///  /__| |\/| | | _   /_\  makes it
Bitnet:   MARKV@UKANVAX		\/\/  /    | |  | | |__| /   \ possible...
Internet: markv@kuhub.cc.ukans.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~