osargs functions and 32 bit values

[David Bryan]

Jonathan Coxhead wrote:

>    On 23 Aug 00, at 19:41, Chris Rutter wrote:
> 
>  | An off-topic question: if `UINT_MAX' was 0xffffffffu, and I took the 
>  | number 0xf0f0f0f0 and shifted it left by 8 places, would ANSI guarantee me
>  | that those eight most significant bits would simply be discarded, or do I,
>  | /strictly speaking/, have to AND with a protective mask first?
>  | 
>  | (I could look this up but I suspect Jon will know. ;-)
> 
>    I'd have to look it up too, because the answer's more complicated than 
> you might have thought. The question is, what type is 0xF0F0F0F0? It's not 
> int, because it doesn't fit. There are some complicated rules to decide 
> what it is, but (without checking) I think it's unsigned int. Therefore, 
> all operations work modulo 2^^32, and the answer is 0xF0F0F000. If the type 
> of 0xF0F0F0F0 *was* int (i e, if an int with that value was shifted), the 
> answer would be undefined (I think).

As the constant 0xf0f0f0f0 doesn't have a suffix, the choices go

  int -> long int -> unsigned long int

As I can't think of a compiler for the ARM which doesn't have both
32bit ints and long ints, unsigned int seems close enough.  (Both
the ARM and gcc compilers use "long long" to denote 64bits.)

-- 
David Bryan