Re: Fix nested functions

[Jan Hubicka <hubicka at ucw dot cz>]

> Jan Hubicka wrote:
> 
> > > The predicate *does* not allow a label_ref here, but it is never checked
> > > because the insn isn't re-recognized any longer after your change.
> > Is it?  I tought that there are two paths - one emitting and other
> > validating the change.
> 
> Well, first the insn is simply changed in place:
> 
>           /* We don't normally have an insn matching (set (pc) (pc)), so
>              check for this separately here.  We will delete such an
>              insn below.
> 
>              For other cases such as a table jump or conditional jump
>              where we know the ultimate target, go ahead and replace the
>              operand.  While that may not make a valid insn, we will
>              reemit the jump below (and also insert any necessary
>              barriers).  */
>           if (n_sets == 1 && dest == pc_rtx
>               && (trial == pc_rtx
>                   || (GET_CODE (trial) == LABEL_REF
>                       && ! condjump_p (insn))))

I see, adding "&& !LABEL_REF_NONLOCAL_P (trial)" would probably help
here, I will test the change tomorrow.
>             {
>               SET_SRC (sets[i].rtl) = trial;
>               cse_jumps_altered = 1;
>               break;
>             }
> 
> and later it is reemitted, which is supposed to heal all broken insns.
> Except you switched off the reemitting ;-)
> 
> > In addition to this we have LABEL_REF_NONLOCAL_P flag and the LABEL_REF
> > is reconstructed.
> 
> Hmm.  Is this completely redundant, or what's the point of having
> to distinct mechanisms?

the nonlocal gotos are usually indirect, so one mechanizm is marking the
indirect goto while the other is marking the actual label when it is
load to register, I think.

Thanks,
Honza