debug insns in SMS

[Alexandre Oliva]

On May  4, 2011, Alexandre Oliva <aoliva@redhat.com> wrote:

> I think this will restore proper functioning to SMS in the presence of
> debug insns.  A while ago, we'd never generate deps of non-debug insns
> on debug insns.  I introduced them to enable sched to adjust (reset)
> debug insns when non-debug insns were moved before them.  I believe it
> is safe to leave them out of the SCCs.  Even though this will end up
> causing some loss of debug info, that's probably unavoidable, and the
> end result after this change is pobably the best we can hope for.  Your
> thoughts?

Actually...  We can probably do better.  Leaving the debug insns out, we
have no way to adjust (reset) them when non-debug insns that depended on
them were moved across them, rendering the debug value incorrect.

I'm now trying to find out some way to add the tracking of these deps to
the DDG in a way that doesn't change the SCCs because of -g, but that
enables us to adjust (or even modulo-schedule) debug insns accurately.

Suggestions would be appreciated.

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer