Re: some basic problems with ppc assembler
On Wed, Jun 25, 2003 at 01:56:54PM -0700, Brad Boyer wrote:
> On Wed, Jun 25, 2003 at 05:02:40PM +0000, paubert wrote:
> > It is specified in the ABI for functions with variable number of argumentsi:
> > the crxor indicates that no parameters have been passed in the floating point
> > registers so an integer only task will not save fpr1-fpr8 to walk the
> > argument list in va_arg. OTOH if you call a variadic functions with
> > floating point parameters, the call will be preceded by creqv 6,6,6.
> Do you actually have a document for the official ABI? I found a link
> to a document in some old messages, but it was a dead link. A generic
> search of the web didn't turn up anything, although I might have
> been searching for the wrong words...
I believe it's still somewhere on the net, Google is your friend,
the keyword is sysv_abi.
> I've been trying to piece it together based on gcc, but that's
> kind of a clumsy way to figure it out.
Indeed, good luck trying to understand GCC's parameter passing code.
Especially for varargs since I believe the 32 bit PPC is by far
the most complex.