Re: [tip:x86/mce] x86/bitops: Move BIT_64() for a wider use

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, May 23, 2012 at 09:11:51AM -0700, H. Peter Anvin wrote:
> On 05/23/2012 09:10 AM, Peter Zijlstra wrote:
> > On Wed, 2012-05-23 at 09:07 -0700, tip-bot for Borislav Petkov wrote:
> >> +#define BIT_64(n)                      (U64_C(1) << (n))
> > 
> > Because writing 1ULL << n is too much work? 
> > 
> 
> Because writing 1ULL << n is broken in anything that needs to be used in
> assembly, for example.

Actually we need a BIT() macro that works both
on 32- and 64-bit. But that won't be that easy:
http://lkml.indiana.edu/hypermail/linux/kernel/1010.1/02335.html

And it should return UL for shift values < 32 and ULL otherwise.

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Stable Commits]     [Linux Stable Kernel]     [Linux Kernel]     [Linux USB Devel]     [Linux Video &Media]     [Linux Audio Users]     [Yosemite News]     [Linux SCSI]

  Powered by Linux