Re: GNAT 4.4.5 Record Bit_Order Endian issues

[Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>]

On 01/21/2013 08:21 PM, Stephen Leake wrote:
>
> 2/2
> R.C'Position
>
>                 {AI95-00133-01AI95-00133-01} If the nondefault bit
>                 ordering applies to the composite type, and if a
>                 component_clause specifies the placement of C, denotes
>                 the value given for the position of the
>                 component_clause; otherwise, denotes the same value as
>                 R.C'Address - R'Address. The value of this attribute is
>                 of the type universal_integer.
>
> Note the 'otherwise'; that's means the value is R.C'Address - R'Address
> only if position is _not_ specified in a rep clause.

No. This says

if A and B then
    D;
else
    E;
end if;

A = "the nondefault bit ordering applies to the composite type"
B = "a component_clause specifies the placement of C"
D = "denotes the value given for the position of the component_clause"
E = "denotes the same value as R.C'Address - R'Address"

The negation of "A and B" is "not A or not B". Thus E holds when the default bit 
ordering applies, even if the position is specified.

-- 
Jeff Carter
"To Err is human, to really screw up, you need C++!"
Stéphane Richard
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