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From: "law at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/107114] [13 Regression] Failure to discover range results in bogus warning
Date: Mon, 03 Oct 2022 17:37:29 +0000	[thread overview]
Message-ID: <bug-107114-4-PGt7EufVOK@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107114-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107114

--- Comment #2 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Which is just uber-weird.  The change in question removes a little subloop
which becomes unreachable.  Why that would cause us to be unable to analyze the
remaining key loop for the IV's range is a complete mystery.  Though I guess
I'll have to sit down and debug that a bit.  VRP is just calling into the loop
optimizer to to the IV analysis, right?


WRT the new blocks -- I strongly suspect they're part of normalization of the
loop and putting it into LCSSA form.  I'm not terribly worried about them. 
Typically they're just going to be creating empty loop latches.

  parent reply	other threads:[~2022-10-03 17:37 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-01 17:59 [Bug tree-optimization/107114] New: " jeffreyalaw at gmail dot com
2022-10-01 18:01 ` [Bug tree-optimization/107114] " law at gcc dot gnu.org
2022-10-03 15:46 ` amacleod at redhat dot com
2022-10-03 17:37 ` law at gcc dot gnu.org [this message]
2022-10-03 18:18 ` amacleod at redhat dot com
2022-10-03 18:21 ` law at gcc dot gnu.org
2022-10-06  9:27 ` rguenth at gcc dot gnu.org
2022-12-22 14:32 ` rguenth at gcc dot gnu.org
2023-02-21 13:51 ` rguenth at gcc dot gnu.org

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