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Re: [PATCH, MPX, 2/X] Pointers Checker [7/25] Suppress BUILT_IN_CHKP_ARG_BND optimizations.

From: Jeff Law <law at redhat dot com>
To: Richard Biener <richard dot guenther at gmail dot com>, Ilya Enkovich <enkovich dot gnu at gmail dot com>
Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>
Date: Tue, 05 Nov 2013 10:05:49 -0700
Subject: Re: [PATCH, MPX, 2/X] Pointers Checker [7/25] Suppress BUILT_IN_CHKP_ARG_BND optimizations.
Authentication-results: sourceware.org; auth=none
References: <20131031090213 dot GC54327 at msticlxl57 dot ims dot intel dot com> <CAFiYyc3gBc=CHDranqXo49NG6yFMSc3d-N8buFtjSS5G5Nga5w at mail dot gmail dot com>

On 11/04/13 06:27, Richard Biener wrote:

On Thu, Oct 31, 2013 at 10:02 AM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:

Hi,

Here is a patch which hadles the problem with optimization of BUILT_IN_CHKP_ARG_BND calls.  Pointer Bounds Checker expects that argument of this call is a default SSA_NAME of the PARM_DECL whose bounds we want to get.  The problem is in optimizations which may replace arg with it's copy or a known value.  This patch suppress such modifications.


This doesn't seem like a good fix.  I suppose you require the same on
RTL, that is, have the incoming arg reg coalesced with the use?
In that case better set SSA_NAME_OCCURS_IN_ABNORMAL_PHI.

I agree.  This seems like the wrong direction.

While I don't like abusing SSA_NAME_OCCURS_IN_ABNORMAL_PHI in thismanner, setting that flag should give them precisely the behaviour theywant. That makes me think SSA_NAME_OCCURS_IN_ABNORMAL_PHI is poorlynamed. But addressing that is separate from this patch.

Ilya, can you convert your code to set SSA_NAME_OCCURS_IN_ABNORMAL_PHIand drop this patch?



Jeff

Follow-Ups:
- Re: [PATCH, MPX, 2/X] Pointers Checker [7/25] Suppress BUILT_IN_CHKP_ARG_BND optimizations.
  - From: Ilya Enkovich

References:
- Re: [PATCH, MPX, 2/X] Pointers Checker [7/25] Suppress BUILT_IN_CHKP_ARG_BND optimizations.
  - From: Richard Biener

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