Re: [Qemu-devel] [RFC 19/38] tcg: add tcg_gen_smp_rmb()

[Alex Bennée]

Emilio G. Cota <address@hidden> writes:

> Signed-off-by: Emilio G. Cota <address@hidden>
> ---
>  tcg/tcg-op.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
> index 52482c0..3ec9f13 100644
> --- a/tcg/tcg-op.h
> +++ b/tcg/tcg-op.h
> @@ -716,6 +716,16 @@ static inline void tcg_gen_fence_full(void)
>      tcg_gen_op0(&tcg_ctx, INDEX_op_fence_full);
>  }
>  
> +#if defined(__i386__) || defined(__x86_64__) || defined(__s390x__)
> +static inline void tcg_gen_smp_rmb(void)
> +{ }
> +#else
> +static inline void tcg_gen_smp_rmb(void)
> +{
> +    tcg_gen_fence_load();
> +}
> +#endif

This seems a little pointless wrapping up tcg_gen_fence_load. Could the
magic dealing with the backend not be done with something like
TCG_TARGET_HAS_fence_load. On the x86/x86_64 backends this could then
NOP away.

> +
>  /* QEMU specific operations.  */
>  
>  #ifndef TARGET_LONG_BITS

-- 
Alex Bennée