[Qemu-devel] Re: [PATCH 1/3] TCG: Mac OS X support for ppc64 target

[Andreas Färber]

Am 06.12.2009 um 06:13 schrieb malc:

> On Sun, 6 Dec 2009, Andreas Faerber wrote:
>
> > Darwin/ppc64 does not use function descriptors,
> > adapt prologue and tcg_out_call accordingly.
> > GPR2 is available for general use, so let's use it.
> >
> > http://developer.apple.com/mac/library/documentation/DeveloperTools/Conceptual/LowLevelABI/110-64-bit_PowerPC_Function_Calling_Conventions/64bitPowerPC.html
> >
> > Signed-off-by: Andreas Faerber <address@hidden>
> > Cc: malc <address@hidden>
> > ---
> > tcg/ppc64/tcg-target.c |   30 ++++++++++++++++++++++++++++++
> > 1 files changed, 30 insertions(+), 0 deletions(-)
> >
> > diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
> > index a612e10..bf9b7d9 100644
> > --- a/tcg/ppc64/tcg-target.c
> > +++ b/tcg/ppc64/tcg-target.c

> > @@ -859,10 +882,12 @@ void tcg_target_qemu_prologue (TCGContext *s)
> >         ;
> >     frame_size = (frame_size + 15) & ~15;
> >
> > +#ifndef __APPLE__
> >     /* First emit adhoc function descriptor */
> >     addr = (uint64_t) s->code_ptr + 24;
> >     tcg_out32 (s, addr >> 32); tcg_out32 (s, addr); /* entry point */
> >     s->code_ptr += 16;          /* skip TOC and environment pointer  
> > */
> > +#endif
> >
> >     /* Prologue */
> >     tcg_out32 (s, MFSPR | RT (0) | LR);
>
> The frame format is different to that of PPC-elf64abi, shouldn't  
> really
> make a difference here, then again i don't have access to PPC64 Mac  
> OSX,
> so can't really verify that.

I checked that the linkage area is 48, too, the LR offset is 16, too.
The parameter area was depicted as 64 < 128.
So I guess we're good there.

> Otherwise looks good.. Should i commit it with R13 fixed?

About the callee-save stuff I was less certain. Feel free to make  
modifications (e.g., moving tcg_out_call up?) or have me resubmit.

Thanks,
Andreas