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From: Richard Biener <rguenther@suse.de>
To: Tom de Vries <Tom_deVries@mentor.com>
Cc: "gcc-patches@gnu.org" <gcc-patches@gnu.org>,
	    Sebastian Pop <sebpop@gmail.com>
Subject: Re: [PATCH, PR69110] Don't return NULL access_fns in dr_analyze_indices
Date: Tue, 12 Jan 2016 13:05:00 -0000	[thread overview]
Message-ID: <alpine.LSU.2.11.1601121404480.31122@t29.fhfr.qr> (raw)
In-Reply-To: <5694F5BA.7030207@mentor.com>

On Tue, 12 Jan 2016, Tom de Vries wrote:

> On 12/01/16 12:22, Richard Biener wrote:
> > Doesnt' the same issue apply to
> > 
> > > >unsigned int *p;
> > > >
> > > >static void __attribute__((noinline, noclone))
> > > >foo (void)
> > > >{
> > > >   unsigned int z;
> > > >
> > > >   for (z = 0; z < N; ++z)
> > > >     ++(*p);
> > > >}
> > thus when we have a MEM_REF[p_1]?  SCEV will not analyze
> > its evolution to a POLYNOMIAL_CHREC and thus access_fns will
> > be NULL again.
> > 
> 
> I didn't manage to trigger this scenario, though I could probably make it
> happen by modifying ftree-loop-im to work in one case (the load of the value
> of p) but not the other (the *p load and store).
> 
> > I think avoiding a NULL access_fns is ok but it should be done
> > unconditionally, not only for the DECL_P case.
> 
> Ok, I'll retest and commit this patch.

Please add a comment as well.

> Thanks,
> - Tom
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)

  reply	other threads:[~2016-01-12 13:05 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-12 10:04 Tom de Vries
2016-01-12 11:22 ` Richard Biener
2016-01-12 12:51   ` Tom de Vries
2016-01-12 13:05     ` Richard Biener [this message]
2016-01-12 18:18       ` Tom de Vries
2016-01-13  8:42         ` Richard Biener
2016-01-15 10:16           ` Tom de Vries
2016-01-15 10:18             ` Richard Biener
2016-01-21 23:48           ` Tom de Vries
     [not found]             ` <CAFk3UF9uMs4i4S5S9GdhMOBr-PY-E5PESJUVpCPDEQ2shDCE9Q@mail.gmail.com>
2016-01-23 18:28               ` Tom de Vries
2016-01-23 18:45                 ` Sebastian Pop
2016-01-24  8:05                   ` Richard Biener
2016-01-26 12:13                     ` Tom de Vries
2016-01-26 16:59                       ` Sebastian Pop
2016-01-27 11:34                         ` Tom de Vries

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