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From: andy@cbmvax.commodore.com (Andy Finkel)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: How are some programs SO DAMN SMALL!
Message-ID: <17876@cbmvax.commodore.com>
Date: 22 Jan 91 01:55:17 GMT
References: <1991Jan20.210328.18087@hoss.unl.edu> <702@caslon.cs.arizona.edu>
Reply-To: andy@cbmvax.commodore.com (Andy Finkel)
Organization: Commodore, West Chester, PA
Lines: 49

In article <702@caslon.cs.arizona.edu> dave@cs.arizona.edu (Dave P. Schaumann) writes:
>In article <1991Jan20.210328.18087@hoss.unl.edu> 231b3678@fergvax.unl.edu (CS 231 section 2) writes:
>>I was looking through some programs that were written in C, and I noticed that
>>a few were really SMALL!  Like only 2k for a full-blown clock.  How does the
>>program get so small!  It seems that if I compile a program like
>> 
>>#include <stdio.h>
>>main(){printf("hey man!\n");}
>
>The reason even a minimal C program, ie "main(){}" compiles to ~4K is that it
>you have to link it to the run-time library.  This has code for stuff like
>parsing the command line, and setting up stdin/stdout.  If you had something
>like "main(){real x; x = 0.0;}", it would be even larger, because now you
>would be bringing in all the f.p. routines as well.

>>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.
>
>As you guessed, if you want *really* small code, you have to use assembler.
>Then you only have the code you need to run your program, and no extra hidden
>stuff.
>

Well, actually, the 2.0 commands in the C: directory are written
in C, not assembler.

The reason we can get so small is:

1) we compile without a startup.  For a small command, often the
   startup is a major part of the program itself.

Because these commands get called in a CLI environment, we
can make certain assumptions, and do without a startup.

2) We use 2.0 AmigaDOS calls (ReadArgs() ) to parse the command
   line


		andy
-- 
andy finkel		{uunet|rutgers|amiga}!cbmvax!andy
Commodore-Amiga, Inc.

"God was able to create the world in only seven days because there
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