Re: [PATCH] Fix PR41357

[Jie Zhang <jie dot zhang at analog dot com>]

Jie Zhang wrote:
> Richard Guenther wrote:
> > On Wed, Sep 16, 2009 at 11:37 AM, Dave Korn
> > <dave.korn.cygwin@googlemail.com> wrote:
> > > Richard Guenther wrote:
> > > > On Wed, Sep 16, 2009 at 9:34 AM, Dave Korn
> > > > > gcc/ChangeLog:
> > > > >
> > > > >        * varasm.c (default_encode_section_info): Set 
> > > > > SYMBOL_REF_TLS_MODEL
> > > > >        even for emulated tls.
> > > > >
> > > > >  If there are no regressions, OK for HEAD?
> > > > Isn't it enough to remove the targetm.have_tls check?  Thus, 
> > > > DECL_TLS_MODEL
> > > > should already be TLS_MODEL_EMULATED, no?
> > >  That's what I would have thought at first too, but I read Jakub's 
> > > comment
> > > #13(*) as suggesting that we should hardcode TLS_MODEL_EMULATED because
> > > (somewhat to our surprise) the tls model value in the decl looked 
> > > strange and
> > > possibly bogus (tls-local-exec?), so it makes sense to override it 
> > > here with
> > > what we know is the right value to show to the backend.  I haven't
> > > investigated to find out how the decl's tls model got to be that way 
> > > and if
> > > it's intended or accidental.  (And I'd really rather not get 
> > > sidetracked into
> > > investigating all the plumbing of the tls emulation layer when I just 
> > > want to
> > > get bootstrap fixed so I can get on with updating to head all the 
> > > huge patches
> > > awaiting review that I'm currently carrying around...)
> >
> > I think the variable should have a proper DECL_TLS_MODEL from the start.
> > Where does it get (not) set?
> My question here is TLS_MODEL_EMULATED should be exclusive with other 
> models or not?
After tracing for a while, I think I probably can answer the question 
myself. :-) It seems TLS_MODEL_EMULATED is only set to emutls-prefixed 
variable, like __emutls_v.gomp_tls_data. For the original __thread 
variable, gomp_tls_data in this case, other TLS_MODEL should be used. So 
we cannot set TLS_MODEL_EMULATED from the start.


Jie