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Date: Fri, 28 Dec 2007 16:43:14 +0100
From: Philippe Gerum <rpm@xenomai.org>
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Sender: Philippe Gerum <philippe.gerum@domain.hid>
Subject: Re: [Adeos-main] fastcall and asmlinkage in x86
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To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: adeos-main <adeos-main@gna.org>

Jan Kiszka wrote:
> Hi Philippe,
> 
> most of the code in arch/x86/ipipe_*.c can be pushed into some
> ipipe-common.c, reducing the patch size by 10-20k and improving code
> maintainability.
>
> But one thing is currently blocking a copy&paste move: a lot of
> functions that are declared fastcall on 32 bit are asmlinkage on 64 bit.

2.4/x86 legacy that survived.

> As both asmlinkage and fastcall are meaningless on 64 bit, can we safely
> switch to fastcall?

Yes.

 Or even better, could we drop that redundant
> declarations totally, given that everything is fastcall on 32 bit anyway
> (unless its marked asmlinkage)?
> 

I see -mregparm=3 unconditionally set in arch/x86/Makefile_32, so this
should work. Looking at some assembly call sites (exception
handling/diversion) tends to confirm this; AFAIR we should not have any
regparm(0) code anywhere. Well, if we still do have some, you will be
the first to know...

-- 
Philippe.