Re: [Xen-devel] [PATCH v3 11/24] xen/arm: Let the toolstack configure the number of SPIs

[Julien Grall <julien.grall@xxxxxxxxxx>]

Hi Ian,

On 23/02/15 15:22, Ian Campbell wrote:
> On Fri, 2015-02-20 at 17:29 +0000, Julien Grall wrote:
>> On 20/02/15 16:08, Ian Campbell wrote:
>>> On Wed, 2015-01-28 at 18:26 +0000, Stefano Stabellini wrote:
>>>
>>>>> +        int spi = irq - 32;
>>>>
>>>> unsigned int
>>>
>>> and underflow?
>>
>> No because there is a check (irq < 32) before using the variable spi.
>> It was more convenient to initialize it directly.
> 
> You'd have to be sure that "irq - 32" wasn't undefined behaviour then,
> or the compiler can decide to omit the rest of the function, or perhaps
> just that second check, because things are undefined from the
> initialiser onwards.
> 
> I think with unsigned you are probably ok.

I will move the (irq - 32) after the check for safety.

Regards,

-- 
Julien Grall

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