Re: [Qemu-devel] [PATCH] s390x: Fix stoc direction

[Richard Henderson <rth@twiddle.net>]

On 04/14/2015 06:45 PM, Alexander Graf wrote:
> The store conditional instruction wants to store when the condition
> is fulfilled, so we should branch out when it's not true.
> 
> The code today branches out when the condition is true, clearly
> reversing the logic. Fix it up by negating the condition.
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  target-s390x/translate.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/target-s390x/translate.c b/target-s390x/translate.c
> index 4f82edd..8ae4912 100644
> --- a/target-s390x/translate.c
> +++ b/target-s390x/translate.c
> @@ -3082,6 +3082,10 @@ static ExitStatus op_soc(DisasContext *s, DisasOps *o)
>  
>      disas_jcc(s, &c, get_field(s->fields, m3));
>  
> +    /* We want to store when the condition is fulfilled, so branch
> +       out when it's not */
> +    c.cond = tcg_invert_cond(c.cond);

Doh.

Reviewed-by: Richard Henderson <rth@twiddle.net>


r~