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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: Pass by reference
Date: 10 Apr 2004 07:33:14 +0100
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Vinzent 'Gadget' Hoefler <nntp-2004-04@t-domaingrabbing.de> writes:

> Pat Rogers wrote:
> 
> >If you made the type volatile that would also force by-reference.

C.6(18): If a type is atomic or volatile and it is not a by-copy type,
then the type is defined to be a by-reference type. If any
subcomponent of a type is atomic or volatile, then the type is defined
to be a by-reference type.

> Are you sure? I'm just looking at the assembly ouput of GNAT for a
> procedure that takes a volatile type (memory mapped register) and it
> does't seem so. Even worse, it optimizes the sequence of assignment
> which I need for this register. If you have any idea how can I avoid
> using access types to make it right, I'd be glad to hear it.

I think you need to use inline assembler to be sure.

And to be really sure you may need to use Volatile => True on the
call, I had to (this was GNAT/PowerPC, by the way).

-- 
Simon Wright                               100% Ada, no bugs.