Re: [PATCH v2] hwmon: (corsair-psu) Fix linear11 calculation

On 8/6/26 08:56, Wilken Gottwalt wrote:
...
>>>> +	s64 result = mant * scale;
>>>
>>> Uhm, this is a 32bit multiplicaiton, actully a C gotcha I explain the beginners
>>> in our company. https://godbolt.org/z/eM6TbGG5E
>>>
>>
>> It is, but that is ok and intentional: both mant and exp are guaranteed to be
>> no larger than s16, meaning the result is never larger than s32 and will never
>> overflow.
>>
>>>> -	return (exp >= 0) ? (result << exp) : (result >> -exp);
>>>> +	if (exp >= 0)
>>>> +		result *= (int)(1UL << exp);
>>
>> This is the calculation that can overflow, making it necessary for result to be s64.
> 
> Yeah, it was just funny to see in the wild. It made my day. :D
> 

Guess I lost you there. Do you want me to change it ? I could add a comment, or just
type cast mant to s64. Please let me know.

Thanks,
Guenter