Re: CVS commit: src/sys/arch/amd64/amd64

[Maxime Villard <max%m00nbsd.net@localhost>]

Le 24/02/2018 à 17:30, Christos Zoulas a écrit :
> In article <18bc2a5a-f82d-91ba-5e52-b262c907bd43%m00nbsd.net@localhost>,
> Maxime Villard  <max%m00nbsd.net@localhost> wrote:
> > Le 24/02/2018 à 11:54, Martin Husemann a écrit :
> > > On Sat, Feb 24, 2018 at 11:37:11AM +0100, Maxime Villard wrote:
> > > > If the macro was defined as #if, you would need to do something like:
> > > >
> > > > 	SYSCALL_ENTRY(syscall)
> > > > 	#define SYSCALL_ENTRY_SVS
> > > > 	SYSCALL_ENTRY(syscall_svs)
> > > > 	#undef SYSCALL_ENTRY_SVS
> > > >
> > > > Where SYSCALL_ENTRY would contain another macro that depends on whether
> > > > SYSCALL_ENTRY_SVS is defined.
> > >
> > > Not sure I follow here.
> > >
> > > I would do something like:
> > >
> > > SYSCALL_ENTRY_PLAIN(syscall)
> > > SYSCALL_ENTRY_SVS(syscall_svs)
> > >
> > > and have the SYSCALL_ENTRY_SVS be defined empty ifndef SVS.
> >
> > But then you are duplicating the code that is shared between the two.
>
> Yes, I can see why you prefer macros here, but you are also duplicating
> the stack frame formation code just because in one branch you are using
> r15 and in the other rax. Why not simplify it? or use a macro for it?

Actually I was unhappy about having two different branches too. But thinking
about this, now that we have a dynamic detection for SVS, we can use %rax in
both branches. I've fixed that in rev1.155, now there is no duplication.

Maxime