Geert Uytterhoeven wrote:
[snip]
> > > Strangely, this is actually "correct" behavior. Arguments on
> > > variable-length argument lists are implicitly "promoted" to unsigned
> > > int at the widest. See K&R 2nd ed. A6.1 and A7.3.2.
> >
> > Ugh. Thanks for pointing this out. I wasn't aware of it.
> >
> > printf("%016Lx\n", ~a);
> >
> > Produces the expected output. So it is actually an implementation
> > bug in binutils, which isn't fixable for 2.14 and earlier, because
> > those have to remain at K&R C level. The K&R requirement was only
> > recenly loosened.
>
> How can it print the correct output if ~a is `promoted' to unsigned int, while
> you specify %Lx in the format string?
>From 'info gcc':
Double-Word Integers
====================
ISO C99 supports data types for integers that are at least 64 bits
wide, and as an extension GCC supports them in C89 mode and in C++.
[...]
There may be pitfalls when you use `long long' types for function
arguments, unless you declare function prototypes. If a function
expects type `int' for its argument, and you pass a value of type `long
long int', confusion will result because the caller and the subroutine
will disagree about the number of bytes for the argument. Likewise, if
the function expects `long long int' and you pass `int'. The best way
to avoid such problems is to use prototypes.
Thiemo
