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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 <email@example.com> wrote:
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 this
manner, setting that flag should give them precisely the behaviour they
want. That makes me think SSA_NAME_OCCURS_IN_ABNORMAL_PHI is poorly
named. But addressing that is separate from this patch.
Ilya, can you convert your code to set SSA_NAME_OCCURS_IN_ABNORMAL_PHI
and drop this patch?