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Re: [PATCH] Fix PR67053

From: Marc Glisse <marc dot glisse at inria dot fr>
To: Richard Biener <rguenther at suse dot de>
Cc: gcc-patches at gcc dot gnu dot org
Date: Tue, 11 Aug 2015 10:20:48 +0200 (CEST)
Subject: Re: [PATCH] Fix PR67053
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On Tue, 11 Aug 2015, Richard Biener wrote:

On Tue, 11 Aug 2015, Marc Glisse wrote:

On Wed, 29 Jul 2015, Richard Biener wrote:

The following fixes PR67053 by more closely mirror what fold_binary()s
STRIP_NOPS does to avoid the C++ FE constexpr code to regress.

Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.

Yes, I'm thinking on an automated way to more closely mirror
STRIP_[SIGN_]NOPS behavior (on toplevel args).


As far as I can see, you are not currently checking that these conversions are
NOPs. I didn't test, but I am afraid this may simplify (char)p1==(char)p2 to
false a bit too quickly.


I'm relying on our restrictions on conversions of pointers to integers
which requires same-precision (and thus always NOP-style) here.

Indeed. I had tested yesterday with an older gcc that we were generatingthe problematic pattern (with conversion from pointer to char), but Ican't reproduce today, so I guess I had typoed something :-(


--
Marc Glisse

Follow-Ups:
- Re: [PATCH] Fix PR67053
  - From: Richard Biener

References:
- Re: [PATCH] Fix PR67053
  - From: Marc Glisse
- Re: [PATCH] Fix PR67053
  - From: Richard Biener

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