[mpich-discuss] Possible integer overflows at scale in gather.c

[Ignacio Laguna]

Rob,

Besides these two cases, the other integer operations are safe. Trust me 
on that ;-)

Thanks for the patch! I think it should fix it. I will run the analysis 
again to double check and I will get back to you.

Ignacio


On 10/2/15 11:50 AM, Rob Latham wrote:
>
>
> On 10/01/2015 12:35 PM, Ignacio Laguna wrote:
>
>> Once you have a version I can download with the patches, I can run the
>> analysis again and see if I can catch more things. Just let me know and
>> I would be happy to test it.
>
> I tried to decipher the LLVM output: I see a few more i64 values, but
> not certain I'm reading it correctly.
>
> Does this patch do the trick?
>
> Promoting the declaration of recvcount would work too, but sets off a
> larger cascade of  type promotions.
>
> ==rob
>
>>
>> In general, overflows can also occur in intermediate computations,
>> depending on how code is optimized, I believe.
>>
>> Thanks!
>>
>> Ignacio
>>
>>> ==rob
>>>
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