Date: Wed, 25 May 1994 12:30:08 -0400
From: morphine AT whatever DOT cs DOT jhu DOT edu (Michael Phelps)
Sender: morphine AT whatever DOT cs DOT jhu DOT edu
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: RE:  FW: inline assembler code on PC
Cc: dj AT ctron DOT com

>> Does anybody have examples which use inline assembler code in C programs
>> which can be compiled by DJ gcc on MS-DOS 5.0? What is the correct
>> compiler directive I have to use?
>
>Look at <sys/farptr.h> in 1.11.maint5.  No compiler directives are 
>required

I also want to add inline assembler code, and even after looking at farptr.h,
I'm still baffled.  I know 8086 assembly language (NOT 80386+), and I find
some of the examples in the docs for the GNU assembler to be puzzling.  For
example, the assembler docs has the following:
	asm ("movl %0,r9;movl %1,r10;call _foo"
	      : /* no outputs */
	      : "g" (from), "g" (to)
	      : "r9", "r10");
It almost looks as if the asm() function tries to have a similar format as 
prinf(), but I don't understand the %0, %1, r9, and r10.  Okay, let's say I
want to do something really simple and write a routine that will be the same
as "x++".  Would the following work?
	asm ("inc %0;
	     : "r" (result)
	     : "r" (input));

What if I don't have it in a function, but rather would like to refer to 
variables within the C program?  (ie, can I say "mov ax, _some_variable;" ?)
What I would like to do is to embed assembly language statements like:
		mov	cx, _time_delay;
	loop1:  loop	loop1;
Is there any way I can do this?
	Also, one more thing:  if I assemble a function with another program
and produce and object file to be linked with the compiled C program, how do I
retrieve the variables passed to the function?  (Are they pushed onto the stack,
or what?)
	I apologize if these questions sound really basic; I just couldn't find
enough relevant information in the documentation that I searched through.
						---Michael