Re: [RFC][IPA-VRP] ADDR_EXPR and nonnull

[kugan <kugan dot vivekanandarajah at linaro dot org>]

Hi Richard,


On 20/10/16 18:41, Richard Biener wrote:
> On Thu, 20 Oct 2016, kugan wrote:
>
> > On 20/10/16 01:26, Jan Hubicka wrote:
> > > > > Would excluding weak symbols (I believe I can check DECL_WEAK for this)
> > > > > good
> > > > > enough. Or looking for acceptable subset would work?
> > > >
> > > > I think we should add a symtab helper to tell if address_nonzero_p (if
> > > > that doesn't aleady exist).
> > >
> > > We have node->nonzero_address()
> >
> > Thanks for the pointer. Here is an attempt. Does this look OK?
> >
> > +	  if (TREE_CODE (arg) == ADDR_EXPR)
> > +	    {
> > +	      /* See if the AADR_EXPR is nonnull.  */
> > +	      varpool_node *node = NULL;
> > +	      tree base = TREE_OPERAND (arg, 0);
> > +	      base = get_base_address (base);
> > +
> > +	      if (decl_address_ip_invariant_p (base)
> > +		  || !is_global_var (base))
> > +		{
> > +		  /* If the symbol address is local or
> > +		     constant.  */
>
> "constant" doesn't matter.  You want
>
>    if (TREE_CODE (base) == CONST_DECL
> || TREE_CODE (base) == PARM_DECL
> || TREE_CODE (base) == RESULT_DECL)
>   addr_nonzero = true;
>    else if (VAR_P (base))
>      addr_nonzero = ! is_global_var (base) || (varpool_node::get
> (base)->nonzero_address ());

Attached patch does this. Bootstrapped and regression tested on 
x86_64-linux-gnu. Is this OK?

Thanks,
Kugan

> Richard.
>
> > +		  addr_nonzero = true;
> > +		}
> > +	      else
> > +		{
> > +		  /* If symbol address is nonzero_address.  */
> > +		  node = varpool_node::get (base);
> > +		  if (node && node->nonzero_address ())
> > +		    addr_nonzero = true;
> > +		}
> > +	    }
> >
> > Attached patch passes bootstrap and regression testing on x86_64-linu-gnu.
> >
> > Thanks,
> > Kugan
> >
> > > Honza
> > > > Richard.
> > > >
> > > > > Thanks,
> > > > > Kugan
> > > > >
> > > > > > Richard.
> > > > > >
> > > > > > > Attached patch bootstraps and regression testing didn't introduce
> > > > > > > any new
> > > > > > > regressions.
> > > > > > >
> > > > > > > Thanks,
> > > > > > > Kugan
> > > > > > >
> > > > > > >
> > > > > > > gcc/ChangeLog:
> > > > > > >
> > > > > > > 2016-10-19  Kugan Vivekanandarajah  <kuganv@linaro.org>
> > > > > > >
> > > > > > > 	* ipa-prop.c (ipa_compute_jump_functions_for_edge): Set
> > > > > > > 	value range to nonull for ADDR_EXPR.
> > > > > > >
> > > > > > > gcc/testsuite/ChangeLog:
> > > > > > >
> > > > > > > 2016-10-19  Kugan Vivekanandarajah  <kuganv@linaro.org>
> > > > > > >
> > > > > > > 	* gcc.dg/ipa/vrp5.c: New test.
> > > > > > > 	* gcc.dg/ipa/vrp6.c: New test.
> > > >
> > > > --
> > > > Richard Biener <rguenther@suse.de>
> > > > SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
> > > > 21284 (AG Nuernberg)

Attachment: p.txt
Description: Text document