Bit flip only function?

[Richard Damon]

On 7/20/14, 12:22 PM, Viktor Kletzhändler wrote:
> Thanks for the reply.
>
> mpz_com seems to do more than flipping.
>
> For example, for a base-2 number
> mpz_com ( 1111 1111 ) returns ( -1 0000 0000 )
> whereas I would like _dcom ( 1111 1111 ) returns ( 0 ).
>
> Am I missing something?
>
> --vk
>
I suspect that what you are missing is that the binary value 1111 1111 
if it really means 255 decimal is REALLY the bit pattern
+0 1111 1111 (to store the sign bit), and thus the complement would be 
-1 0000 0000 (where the sign is used to indicate that the leading bit is 
replicated to infinity (but can be ignored for value).

-- 
Richard Damon