Re: [patch 14/44] generic hweight{64,32,16,8}()

Andi Kleen <[email protected]> Wed, 01 Feb 2006 10:24:27 +0000

Newsgroups	org.kernel.vger.ultralinux,org.kernel.vger.linux-ia64,org.kernel.vger.linux-kernel,org.kernel.vger.linux-mips,org.kernel.vger.sparclinux,org.ozlabs.lists.linuxppc-dev
Message-ID	<[email protected]>

On Wednesday 01 February 2006 10:26, Michael Tokarev wrote:
> Andi Kleen wrote:
> > On Wednesday 01 February 2006 10:02, Akinobu Mita wrote:
> > 
> >>+static inline unsigned int hweight32(unsigned int w)
> []
> > How large are these functions on x86? Maybe it would be better to not inline them,
> > but put it into some C file out of line.
> 
> hweight8	47 bytes
> hweight16	76 bytes
> hweight32	97 bytes
> hweight64	56 bytes (NOT inlining hweight32)
> hweight64	197 bytes (inlining hweight32)
> 
> Those are when compiled as separate non-inlined functions,
> with pushl %ebp and ret.

This would argue for moving them out of line.

-Andi