Re: [avr-gcc-list] compilation results with avr-gcc 4.8.3

[Richard Weickelt]

Hi,

>> Is it fair to conclude that the ~
>> operator, applied to an unsigned char, does produce an int as output
>> instead of the input type?
> 
> Yes, this is exactly what the C standard promotion rules require.
> 
> Well, to be exact, they *require* it behaves "as if" it were promoted
> to "int", so if the sign extension has no net effect to the result, it
> might be left out as well.  So in that sense, it might be considered a
> "missed optimization" bug in GCC here, but it's probably always hard
> to catch all those situations well were the integer promotion could be
> bypassed.

I remember vaguely somebody's proposal on this list to write a C++ class for
unsigned char in order to "bypass" promotion rules. Has anyone tried that?
Just being curious.

Richard