Re: [PATCH] powerpc: inline current_stack_pointer()

From: Segher Boessenkool
Date: Tue May 24 2016 - 02:09:24 EST


On Tue, May 24, 2016 at 07:39:59AM +0200, Christophe Leroy wrote:
> >>+static inline unsigned long current_stack_pointer(void)
> >>+{
> >>+ register unsigned long *ptr asm("r1");
> >>+
> >>+ return *ptr;
> >>+}
> >Register asm is only guaranteed to work as input to inline asm. NAK.
> >
> Does it mean that the following declaration in
> arch/powerpc/include/asm/paca.h is wrong too ?
>
> register struct paca_struct *local_paca asm("r13");

That one is fine, because it is a global var.

https://gcc.gnu.org/onlinedocs/gcc/Explicit-Register-Variables.html


Segher