On Fri, 19 Aug 2016, Jonathan Wakely wrote:
On 19 August 2016 at 09:53, Jonathan Wakely wrote:
On 19 August 2016 at 09:07, Jeffrey Walton wrote:
You've basically gone chasing after some unrelated definition (that of
uint64_t) which has nothing to do with _rdrand64(), looking at
unrelated implementation details of that different type, and the
simple solution is to just use the type in the function declaration.
That's how Intel documents it.
They document it as unsigned __int64 but that's not a standard type.
That's not a standard type. You found some definition of __int64 in a
different set of GCC headers and chased that, but there's no guarantee
that the header you looked in defined it consistently with how it's
used in the Intel docs.
A long time ago I was told to use Intel's documentation because GCC
does not provide it (cf.,
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=68081).
GCC might not document the function, but the header unambiguously
defines the function signature, and it takes unsigned long long*.
Arguably the GCC intrinsic should use uint64_t* but it doesn't, so the
answer to your original question is still to simply use the right
type. And the right type was shown in the error messages you quoted in
your first mail.
If a function is declared to take X* and you get an error when passing
Y* the solution is to pass X* instead.
We could overload the function in C++ in 64-bit mode, but that may break
code that tries to use a function pointer.
--
Marc Glisse
