Hi,

> On 7 Nov 2014, at 07:52, Anand Avati <av...@gluster.org> wrote:
> On Thu, Nov 6, 2014 at 8:22 PM, Anton Altaparmakov <ai...@cam.ac.uk> wrote:
> > On 7 Nov 2014, at 01:46, Jeff Moyer <jmo...@redhat.com> wrote:
> > Minor nit, but I'd rather read something that looks like this:
> >
> >       if (type == READ && (flags & RWF_NONBLOCK))
> >               return -EAGAIN;
> >       else if (type == WRITE && (flags & RWF_DSYNC))
> >               return -EINVAL;
> 
> But your version is less logically efficient for the case where "type == 
> READ" is true and "flags & RWF_NONBLOCK" is false because your version then 
> has to do the "if (type == WRITE" check before discovering it does not need 
> to take that branch either, whilst the original version does not have to do 
> such a test at all.
> 
> Seriously?

Of course seriously.

> Just focus on the code readability/maintainability which makes the code most 
> easily understood/obvious to a new pair of eyes, and leave such 
> micro-optimizations to the compiler..

The original version is more readable (IMO) and this is not a 
micro-optimization.  It is people like you who are responsible for the fact 
that we need faster and faster computers to cope with the inefficient/poor code 
being written more and more...

And I really wouldn't hedge my bets on gcc optimizing something like that.  The 
amount of crap assembly produced from gcc that I have seen over the years 
suggests that it is quite likely it will make a hash of it instead...

Best regards,

        Anton

> Thanks

-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
University of Cambridge Information Services, Roger Needham Building
7 JJ Thomson Avenue, Cambridge, CB3 0RB, UK

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