Re: [PATCH 1/1] vsprintf: optimize decimal conversion (again)

H. Peter Anvin
2012-03-26T20:21:04Z

On 03/26/2012 01:13 PM, Andrew Morton wrote:
> On Mon, 26 Mar 2012 21:56:38 +0200
> Denys Vlasenko <vda.linux@googlemail.com> wrote:
>
>>>> +#if BITS_PER_LONG != 32 || (~(0ULL)>>1) != ((1ULL<<63)-1)
>>>
>>> What's this for?
>>
>> The second check should be just BITS_PER_LONG_LONG != 64,
>> but we don't have BITS_PER_LONG_LONG.
>
> So let's add BITS_PER_LONG_LONG rather than hacking around its absence!

First of all, the #if is wrong: the preprocessor doesn't support data
types and does all arithmetic at (u)intmax_t precision.

As far as BITS_PER_LONG_LONG, there are tons of places in the kernel
which already require that long long is exactly 64 bits. That may or
may not be a good thing, but for right now one could simply:

#define BITS_PER_LONG_LONG 64

-hpa