[PATCH] Exploiting dual mode operation, implementation.

[Steven Bosscher]

On Friday 24 June 2005 13:29, Daniel Berlin wrote:
> > There certainly are other parts in the compiler where it can be a
> > problem, though most passes, AFAICT, do handle PARALLELs.  But gcse PRE
> > does not.
>
> I'm pretty sure this isn't true anymore.
> The comments claim it is, but the code shows otherwise.
>
> Certainly, cprop and friends don't deal with PARALLEL's, but PRE does.
>
> See hash_scan_insn and mark_oprs_set

Hmm, I believed it was the other way around: CPROP does handle PARALLELs
but PRE does not.  Wasn't there the issue that it doesn't know how to
insert insns that are PARALLELs?

Anyway, this comment before pre_gcse ought to be fixed if you are right:

   ??? We don't handle single sets in PARALLELs because we're [currently] not
   able to copy the rest of the parallel when we insert copies to create full
   redundancies from partial redundancies.  However, there's no reason why we
   can't handle PARALLELs in the cases where there are no partial
   redundancies.  */

Hmm, strange...  *confused*

Gr.
Steven