unsigned / double propagation weirdness?

[Segher Boessenkool]

On 24-feb-04, at 13:23, Robert Dewar wrote:

> Joe Buck wrote:
>
>> So the warning would only be generated if an unsigned negation is
>> widened (or potentially widened, in the case of conversions to long,
>> to alert the programmer to portability issues).
>> This should eliminate Robert's concerns about intentional use of -
>> for two's complement: in such cases, the result would not be widened.
>
> Yes, that sounds right, although I wonder how common this case is ...

Well there's other cases resulting in the same problem as well...

See e.g. http://gcc.gnu.org/ml/gcc-patches/2003-12/msg01303.html .


Segher