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From: "uweigand at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug regression/53729] [4.8 regression] PR53636 fix caused bb-slp-16.c to FAIL on sparc64 and powerpc64
Date: Wed, 20 Jun 2012 15:22:00 -0000	[thread overview]
Message-ID: <bug-53729-4-FmTAWNMKv9@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-53729-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53729

Ulrich Weigand <uweigand at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-06-20
         AssignedTo|unassigned at gcc dot       |uweigand at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #1 from Ulrich Weigand <uweigand at gcc dot gnu.org> 2012-06-20 15:22:45 UTC ---
The problem is that SLP tests *all* accesses within the basic block for
alignment, even those that aren't actually part of a SLP instance.

This is of course broken, but that bug had been hidden by the PR53636 problem
(due to which accesses were considered aligned that actually are not).

The fix for this problem is to only check *relevant* accesses for alignment. 
(This requires moving the alignment check until after relevant statements are
actually marked ...)

I'm testing a fix.


  parent reply	other threads:[~2012-06-20 15:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-20 11:26 [Bug regression/53729] New: " mikpe at it dot uu.se
2012-06-20 11:33 ` [Bug regression/53729] " rguenth at gcc dot gnu.org
2012-06-20 15:22 ` uweigand at gcc dot gnu.org [this message]
2012-06-26  9:06 ` uweigand at gcc dot gnu.org
2012-06-26  9:09 ` uweigand at gcc dot gnu.org

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