[patch] Fix PR43464: update loop closed SSA form once copy prop is done

[Jack Howarth]

On Fri, Apr 02, 2010 at 12:56:36PM +0200, Richard Guenther wrote:
> On Thu, Apr 1, 2010 at 8:24 PM, Sebastian Pop <sebpop@gmail.com> wrote:
> > On Thu, Apr 1, 2010 at 08:48, Richard Guenther <rguenther@suse.de> wrote:
> >> Sort of.  Only verify loop closed SSA if loop_state_satisifes_p
> >> has LCSSA.
> >
> > done, see 0001
> >
> >>  Also add a param to verify_loop_closed_ssa whether
> >> verify_ssa should be called inside it (we do that from passes.c
> >> already, so avoid the duplicate).
> >
> > done, see 0002
> >
> >>  For simplicity I'd just
> >> add TODO_verify_loops to the flags when loop state satisifes
> >> LCSSA in passes.c (which can then also avoid passing true to
> >> verify_loop_closed_ssa if ssa verification was already done).
> >>
> >
> > This confuses me: why do you want to keep the TODO_verify_loops?
> > TODO_verify_loops won't have any effect on all the LNO passes
> > if I'm adding this change to execute_function_todo
> >
> > if (current_loops && loops_state_satisfies_p (LOOP_CLOSED_SSA))
> >  flags = flags & TODO_verify_loops;
> 
> Indeed.  Deleting the TODO as you do is also ok.
> 
> The patches are ok for 4.6 stage1.
> 

Richard,
   Will these be suitable for backporting into gcc 4.5 branch
after the gcc 4.5.0 release? Reading the gcc 4.6 plans...

http://gcc.gnu.org/ml/gcc/2009-09/msg00501.html

...it would appear that gcc 4.6 could be a rather odd
release since it mainly focuses on compiler tuning rather
than new branches being merged. The cut-off for what is
backportable might be fuzzier than in the past development
cycles.
                  Jack

> Thanks,
> Richard.
> 
> > Sebastian
> >