Re: [libvirt] [PATCH] Reusing the result of virArchFromHost instead of calling it multiple times

On 04/09/2013 12:38 AM, Tal Kain wrote: > On Mon, Apr 8, 2013 at 4:32 PM, Daniel P. Berrange <berrange(a)redhat.com >wrote: > >> On Mon, Apr 08, 2013 at 03:33:07PM +0300, Tal Kain wrote: >>> Signed-off-by: Tal Kain <tal.kain(a)ravellosystems.com&gt; >>> --- >>> src/qemu/qemu_capabilities.c | 13 +++++++------ >>> 1 file changed, 7 insertions(+), 6 deletions(-) >> >> What is the motivation for doing this ? it just looks like >> overkill to me, since virArchFromHost isn't really an >> expensive method to invoke. >> > This patch's motivation is not about making this function faster. > Even if virArchFromHost isn't expensive, It seemed to me like there is no > good reason for calling it 3 times at the same context, It is just > unnecessary. > Why using a local variable instead of calling the same function three times > is an overkill? Personally, I don't think the patch is too bad, and I'll probably apply it unless Dan can give a stronger objection. > >>From my perspective, by calling it just once I'm making it easier for a > reader to understand the usage of this function without reading its code. A good compiler will already factor out invariant calls; but we don't use enough annotations to tell the compiler that virArchFromHost is invariant. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org