Re: [RFC] Fix PR19401: always completely peel loops

[Richard Guenther <richard dot guenther at gmail dot com>]

On Thu, 13 Jan 2005 13:51:27 -0500, Paul Schlie <schlie@comcast.net> wrote:
> > Richard Guenther writes:
> > This minimal patch unconditionally enables complete loop peeling
> > at the tree level.
> 
> Isn't it rather presumptuous to assume that such a thing is universally
> beneficial to all targets?
> 
> (as would expect it to predominantly result in bloated code for smaller
> lightly pipelined targets, with little if any tangible benefit; unless I
> misunderstand?)

Sure.  I guess maybe we should do this for the C++ frontend only - it
is not only for loop optimization itself, but also would expose more
variables to scalarization (if only complete loop peeling was run
before scalarization).  I should probably file another bug wrt the
lack of scalarization for

int a[4];
for (int i=0; i<4; ++i)
  a[i] = i;

(or better a more useful example where scalarization has a benefit)

Richard.