Re: Bitordering? was Re: Bitmanipulation in Ada

[Alfred Hilscher <SPAM@alfred-hilscher.de>]

Georg Bauhaus schrieb:
> 
> Nick Roberts <nick.roberts@acm.org> wrote:
> : On Fri, 20 Aug 2004 22:57:40 +0200, Alfred Hilscher
> : <SPAM@alfred-hilscher.de> wrote:
> :
> :> When I declare an boolean array with eight elements 1..8 (e.g. to
> :> address a hardware port with eight status bits), how are they
> :> ordered is X(1) the msb or the lsb of the byte?
> :
> : It is undefined.
> :
> : The typical way to deal with this kind of situation is to use a
> : record type with a record representation clause. For example:
> 
> [...]
> 
> You might also be interested in the Bit Order paper by Norman Cohen
> available in the grab bag at http://www.ada-auth.org
> 
> -- Georg

Very interessting. Thanks.

I worked in the range of telecommunication (with CHILL) and our compiler
had directives (pragmas) to tell him which variable should be treated as
big-endian, bzw little endian. In the case of mixed expressions, the
compiler generated code to change the representation. This siplyfied the
code in some situations.


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