From: Steven Bosscher <stevenb.gcc@gmail.com>
To: Peter Bergner <bergner@vnet.ibm.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>,
Richard Biener <richard.guenther@gmail.com>
Subject: Re: [PATCH] Fix PR middle-end/81564: ICE in group_case_labels_stmt()
Date: Thu, 27 Jul 2017 17:22:00 -0000 [thread overview]
Message-ID: <CABu31nOQMyxSQ7pLY0XWwHoVT-GEzamU1PcGkqkV8fGJQL2aYQ@mail.gmail.com> (raw)
In-Reply-To: <07274faa-1ee9-fa6c-57a6-e77ed47a3f7f@vnet.ibm.com>
On Wed, Jul 26, 2017 at 9:35 PM, Peter Bergner wrote:
> The test case for PR81564 exposes an issue where the case labels for a
> switch statement point to blocks that have already been removed by an
> earlier call to cleanup_tree_cfg(). In that case, the code in
> group_case_labels_stmt() that does:
How can a basic block be removed (apparently as unreachable) if there
are still case labels leading to it?
Apparently there is enough information to make CASE_LABEL be set to
NULL. Why is the case label not just removed (or redirected to the
default, or ...)?
The patch feels like it's papering over another issue.
group_case_labels is an optional thing to do, basically just a
simplification. The compiler should run even if you never group the
case labels...
Ciao!
Steven
next prev parent reply other threads:[~2017-07-27 17:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-26 19:35 Peter Bergner
2017-07-27 7:49 ` Richard Biener
2017-07-27 14:06 ` Peter Bergner
2017-07-27 17:22 ` Steven Bosscher [this message]
2017-07-28 1:07 ` Peter Bergner
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