Re: [PATCH 2/5] bitops: compile time optimization forhweight_long(CONSTANT)

[Peter Zijlstra]

On Thu, 2010-02-04 at 16:54 +0100, Borislav Petkov wrote:
> On Thu, Feb 04, 2010 at 04:13:52PM +0100, Peter Zijlstra wrote:
> > hweight_long() isn't an arch primitive, only __arch_hweight{8,16,32,64}
> > are.
> 
> Yeah, I'm still looking for the proper location. hweight_long() is the
> generic version so do we want to do the
> 
> #ifndef __HAVE_ARCH_POPCNT
> static inline unsigned long hweight_long(unsigned long w)
> ....
> 
> #endif
> 
> thing and define a x86-specific version? 

No, just don't touch hweight_long(), simply provide
__arch_hweight{8,16,32,64} and all will be well.

hweight_long() is provided by <include/linux.h> and is constructed from
height32() and hweight64() depending on the actual word size.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/