Date: Fri, 18 Oct 1996 16:31:15 +0000
From: Bill Currie <billc AT blackmagic DOT tait DOT co DOT nz>
Subject: Re: Some Inline ASM questions
To: khcm6sh AT dmu DOT ac DOT uk
Cc: djgpp AT delorie DOT com
Message-id: <3267B0D3.2632@blackmagic.tait.co.nz>
Organization: Tait Electronics NZ
MIME-version: 1.0
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References: <326651D4 DOT 7250 AT dmu DOT ac DOT uk>

Simon Hammett wrote:
> some_routine()
> {
> asm     ("
> 
>         movl    _Y_coord, %eax
>         imul    $HREZ, %eax
> 
>         ");
> }change to:
some_routine()
{
asm     ("

        movl    _Y_coord, %%eax
        imul    $%0, %%eax

        "
        : 
        :"i"(HREZ));
}

> int     some_function ( int x, int y );
> {
> asm     ("
> 
>         movl    X(%sp), %eax
>         imul    Y(%sp), %eax
>         movl    %eax, RESULT( %sp )
> 
>         ");
> }chage to:
int     some_function ( int x, int y );
{
int result;
asm     ("
        imul    %2, %%eax
        "
	:"=a"(result)
	:"a"(x),"g"(y) );
}


Basically, extended inline asm makes life much easier. (type 'info gcc "c ex" ex' to get more 
info)

Hope this helps
Bill