On Fri, 20 Nov 2015, Tom de Vries wrote:
> On 20/11/15 11:37, Richard Biener wrote:
> > I'd rather make loop_optimizer_init do nothing
> > if requested flags are already set and no fixup is needed
>
> > Thus sth like
> >
> > Index: gcc/loop-init.c
> > ===================================================================
> > --- gcc/loop-init.c (revision 230649)
> > +++ gcc/loop-init.c (working copy)
> > @@ -103,7 +103,11 @@ loop_optimizer_init (unsigned flags)
> > calculate_dominance_info (CDI_DOMINATORS);
> >
> > if (!needs_fixup)
> > - checking_verify_loop_structure ();
> > + {
> > + checking_verify_loop_structure ();
> > + if (loops_state_satisfies_p (flags))
> > + goto out;
>
> What about flags that are present in the loops state, but not requested in
> flags? Should we try to clear those flags?
No, I don't think so, that would break in-loop-pipeline LIM, dropping
loop-closed SSA for example.
I agree it's somewhat of an odd behavior but all passes should
either be placed in a sub-pipeline with an outer
loop_optimizer_init()/finalize () call or call both themselves.
Richard.
> Thanks,
> - Tom
>
> > + }
> >
> > /* Clear all flags. */
> > if (recorded_exits)
> > @@ -122,11 +126,12 @@ loop_optimizer_init (unsigned flags)
> > /* Apply flags to loops. */
> > apply_loop_flags (flags);
> >
> > + checking_verify_loop_structure ();
> > +
> > +out:
> > /* Dump loops. */
> > flow_loops_dump (dump_file, NULL, 1);
> >
> > - checking_verify_loop_structure ();
> > -
> > timevar_pop (TV_LOOP_INIT);
> > }
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
