Re: [PATCH v3 1/2] xen/arm: Start to implement an ARM decoder instruction

[Julien Grall <julien.grall@linaro.org>]

On 07/31/2013 05:26 PM, Ian Campbell wrote:
> On Wed, 2013-07-31 at 17:18 +0100, Julien Grall wrote:
> 
> 
>>>> +        switch ( opB & 0x3 )
>>>> +        {
>>>> +        case 0:
>>>> +            dabt->size = 2;
>>>> +            break;
>>>> +        case 1:
>>>> +            dabt->size = 1;
>>>
>>> ->sign is uninitialised for these two cases?
>>>
>>> Actually, for many of them I think?
>>
>> I plan to zeroed the ISS field (ie sign, reg...) by default. See TODO in
>> decode_instruction. Do I still need to set sign to 0?
> 
> Well, you need to at least do one or the other!
> 
> Even if you are zeroing the iss be default I think it would be useful
> from a documentation/clarity perspective to set it explicitly to zero.

There is only few functions which deal with signed-register. So if we
add a line "dabt->sign = 0" it's less clear. What about a helper?

update_dabt(struct hsr_dabt *dabt, uint16_t reg, uint8_t size,
            bool_t sign)

-- 
Julien