Re: [PATCH v2 01/15] audio: replace open-coded buffer arithmetic

[Gerd Hoffmann]

  Hi,

> > > --- a/audio/audio_int.h
> > > +++ b/audio/audio_int.h
> > > @@ -266,6 +266,12 @@ static inline size_t audio_ring_dist(size_t dst, 
> > > size_t src, size_t len)
> > >       return (dst >= src) ? (dst - src) : (len - src + dst);
> > >   }
> > You haven't touched this function, but while I am looking at it, all 
> > function
> > arguments are unsigned. So probably modulo operator might be used to get rid
> > of a branch here.
> 
> That would be "return (len - dist + pos) % len;" but on my x86_64 system I
> always prefer a conditional move instruction to a 64 bit integer division
> instruction.

Why?  Performance?

Don't underestimate the optimizer of a modern compiler.  In many cases
it simply isn't worth the effort.  Better optimize the code for humans,
i.e. make it easy to read and understand.

take care,
  Gerd