Re: [PATCH] local_t : powerpc extension - use long for powerpc32

From: Mathieu Desnoyers
Date: Thu Feb 15 2007 - 16:23:23 EST


* Kumar Gala (galak@xxxxxxxxxxxxxxxxxxx) wrote:
>
> On Feb 15, 2007, at 2:02 PM, Mathieu Desnoyers wrote:
>
> >* Kumar Gala (galak@xxxxxxxxxxxxxxxxxxx) wrote:
> >>is there a reason this isn't local_add_return(long a, local_t *l) on
> >>ppc32?
> >>
> >>(same comment for other functions)
> >>
> >>- k
> >
> >no, except that we use the code is taken from atomic.h and used an
> >int parameter. However, due to the semantics of local_t, we should
> >manipulate longs instead of ints, even if they are the same size on a
> >given architecture (ppc32 and mips32 are affectec by this).
> >
> >Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
>
> Right, this means we can simply for ppc version down to:
>
> +static __inline__ int local_add_return(int a, local_t *l)
> +{
> + int t;
> +
> + __asm__ __volatile__(
> +"1: PPC_LLARX %0,0,%2 # local_add_return\n\
> + add %0,%1,%0\n"
> + PPC405_ERR77(0,%2)
> +" PPC_STLCX %0,0,%2 \n\
what about the dot after stwcx ? (stwcx.) ? Is it no longer required ?

> + bne- 1b"
> + : "=&r" (t)
> + : "r" (a), "r" (&(l->a.counter))
> + : "cc", "memory");
> +
> + return t;
> +}
>
> and that should work for both ppc32 & ppc64 and removes the
> duplication between the two.
>
> - k
>

--
Mathieu Desnoyers
Computer Engineering Ph.D. Candidate, École Polytechnique de Montréal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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