Re: [PATCH] rtlopt branch merge part 5 -- loop unswitching

[Jan Hubicka <jh at suse dot cz>]

> Hello,
> 
> >     + /* Unswitch LOOPS.  */
> > 
> > I would expect to see at least a couple of paragraphs here saying what 
> > "loop unswitching" does.
> 
> use google? I really find little sense in explaining this; it would be
> other matter if it was something non-trivial, but this is something
> that simply cannot be done in much different way.

I guess there are people playing around with GCC who are not familiar
with this.  Adding comment to the top of file saying something like:

Transform loops:
  while
    {
      if (invariant)
        code
      ...
    }
Into
  if (invariant)
    while
      {
        code
	....
      }
   else
     while
      {
        ....
      }
Won't hurt I guess.

Honza
> 
> > There are *very few* comments at all in these
> > files and absolutely no overview of what they are doing.
> 
> Sorry, but there are generally comments every 5-10 lines and I refuse
> to write more.
> 
> Zdenek