Re: [PATCH] Fix ix86_split_long_move collision handling with TLS (PR target/66470)

[Jakub Jelinek <jakub@redhat.com>]

On Tue, Jun 09, 2015 at 04:12:33PM +0200, Uros Bizjak wrote:
> On Tue, Jun 9, 2015 at 3:39 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> > On Tue, Jun 09, 2015 at 03:21:55PM +0200, Uros Bizjak wrote:
> >> I'm afraid that simple scan loop won't work correctly on x32. There
> >> are some issues with UNSPEC_TP for this target, so we have to generate
> >> zero_extend of SImode UNSPEC, e.g.:
> >>
> >> (plus:DI (zero_extend:DI (unspec:SI [...] UNSPEC_TP) (reg:DI ...))
> >>
> >> as can be seen in get_thread_pointer to construct the address. It
> >> looks that your loop won't find the UNSPEC_TP tag in the above case.
> >
> > You're right, for -m32 it would need to start with

Yeah, I meant -mx32 (which I have no experience with nor spare time for).

> >    rtx *x = &addr;
> > +  while (GET_CODE (*x) == ZERO_EXTEND
> > +        || GET_CODE (*x) == AND
> > +        || GET_CODE (*x) == SUBREG)
> > +    x = &XEXP (*x, 0);
> 
> Oh, you can use SImode_address_operand predicate here.

Do I need to loop, or can there be just one SImode_address_operand
code?  Do you want to use the iterators (as in the second patch) or not
(then is
  if (SImode_address_operand (addr, VOIDmode))
    x = &XEXP (addr, 0);
ok)?  Is Pmode always SImode for -mx32, or depending on some switch or
something?  Would it be acceptable to just guard the changes in the patch
with !TARGET_X32 and let H.J. deal with that target?  I'm afraid I'm lost
when to ZERO_EXTEND addr (if needed at all), etc.

	Jakub