From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,FREEMAIL_FROM,
	INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,688b25ba856f42d7
X-Google-Attributes: gid103376,public
From: "Nick Roberts" <nickroberts@callnetuk.com>
Subject: Re: question about functions (bis)
Date: 2000/01/24
Message-ID: <388ce9c4@eeyore.callnetuk.com>#1/1
X-Deja-AN: 577162472
References: <8690s0$8tq$1@news.mgn.net>
X-Original-NNTP-Posting-Host: da130d37.dialup.callnetuk.com
X-Trace: 25 Jan 2000 00:09:40 GMT, da130d37.dialup.callnetuk.com
X-MSMail-Priority: Normal
X-Priority: 3
Newsgroups: comp.lang.ada
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600
Date: 2000-01-24T00:00:00+00:00
List-Id: <comp.lang.ada>

The 'nice' solution is simple: declare a temporary of the return type, pass
its address to the hardware, and return it at the end of the function.

   function Add (Left, Right: in T) return T is
      Result: T;
   begin
      ASIC_Add(Left'Address,Right'Address,Result'Address);
      return Result;
   end;

   pragma Inline(Add);

Couldn't be easier!

Note the use of a 'pragma Inline' to (hopefully) help with speed (which I
presume matters in this situation). With a bit of luck, the compiler will
optimise reasonably.

--
Nick Roberts
http://www.adapower.com/lab/adaos

"Pascal LEJEUNE" <pascal.lejeune@matra-transport.fr> wrote in message
news:8690s0$8tq$1@news.mgn.net...
> ...
> Finaly, my function ADD use a hardware component which do
> the operation with the addresses (it's an asic which needs
> to know on which variable the operation is done) :
>
> function ADD (A, B : in T) return T is
>    tmp : system.address;
> begin
>    << find the address of the result (that's my problem !!) >> and
>    put it in a local variable (tmp)
>
>    call a procedure which use directly the hardware :
>    proc (a'address, b'address, tmp);
> end ADD;
>
> So, the problem is quite simple : the type T is a "numerical" type
> on which it is normal to have operators ... but the hardware need
> to have the address of the arguments and the address of the result !!!