Re: [OpenBIOS] [RFC 3/3] SPARC32/64: Mimic Sun's OBP behaviour if a divide by zero occurs.

[Artyom Tarasenko]

Hi Mark,

On Mon, Jan 7, 2013 at 4:07 PM, Mark Cave-Ayland
 wrote:
> As reported by Artyom Tarasenko, if anything is divided by zero then we should
> return no value:
>
> 0 > 4 2 / u. 2  ok
> 0 > 2 0 /  ok

NAK. Either my memory is cheating on me or there is some other Artyom
Tarasenko who reported it. OBP produces an exception in case of
division by zero.

(This time adding you to cc, since the mailing list bounces my mails
saying my emai is graylisted - whatever it means).
> Signed-off-by: Mark Cave-Ayland
>
> openbios-devel/arch/sparc32/init.fs |    7 +++++++
>  openbios-devel/arch/sparc64/init.fs |    7 +++++++
>  2 files changed, 14 insertions(+)
>
> diff --git a/openbios-devel/arch/sparc32/init.fs b/openbios-devel/arch/sparc32/init.fs
> index 7306eab..7d20d4d 100644
> --- a/openbios-devel/arch/sparc32/init.fs
> +++ b/openbios-devel/arch/sparc32/init.fs
> @@ -45,3 +45,10 @@ device-end
>  : obmem ( -- space )
>    0
>    ;
>
> +\ Override divide by zero handling
> +\ Tests indicate that Sun's OBP implementation returns no value in this case
>
> +: (sparc-div-by-zero-handler) 3drop 0 0 ;
>
> +['] (sparc-div-by-zero-handler) to (div-by-zero-handler)
> diff --git a/openbios-devel/arch/sparc64/init.fs b/openbios-devel/arch/sparc64/init.fs
> index a1cadc1..535b7d2 100644
> --- a/openbios-devel/arch/sparc64/init.fs
> +++ b/openbios-devel/arch/sparc64/init.fs
> @@ -53,3 +53,10 @@ device-end
>  : rmap@    ( virt -- rmentry )
>    drop 0
>    ;
>
> +\ Override divide by zero handling
> +\ Tests indicate that Sun's OBP implementation returns no value in this case
>
> +: (sparc-div-by-zero-handler) 3drop 0 0 ;
> +['] (sparc-div-by-zero-handler) to (div-by-zero-handler)
>
> 1.7.10.4