On Tue, 28 Aug 2012, Ulrich Drepper wrote:
On Tue, Aug 28, 2012 at 3:47 AM, Marc Glisse <marc.gli...@inria.fr> wrote:
I assume they are different enough that they can't all be abstracted
behind a nice common builtin (with default implementation in libgcc
and/or a macro advertising fast implementations of it) :-(
What is different is the way to interact with the CPU facility to get
the data. That's exactly the part I abstracted out in its own
function. I named it __x86_rdrand() but that's more an historic
accident. I should have named it __get_random_word. Then all that
needs to be done for another architecture is to provide a definition
of this function. The rest can be shared. But this function needs to
be arch-specific since the details really differ sufficiently.
Thank you for your answers. My main concern was whether it was best to
implement __get_random_word in libstdc++, or __builtin_random in gcc.
But it looks like your solution of doing it in libstdc++ makes more sense
(at least for now).
--
Marc Glisse
