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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/102510] Function call has unnecessary stride check
Date: Tue, 28 Sep 2021 08:54:18 +0000	[thread overview]
Message-ID: <bug-102510-4-5ha4VZ6iSa@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-102510-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102510

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-09-28
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
      Known to fail|                            |12.0
           Keywords|                            |missed-optimization
            Summary|Function call has           |Function call has
                   |unnecessary aliasing check  |unnecessary stride check

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
It's not an alias but we seem to not know that the array stride of the result
is one and thus we version on that.  I'm not sure whether fortran allows

  res(/1, 16, 2/) = add2vecs2(a, b)

or so or why  we know the inputs are not strided.  The result comes in as
array descriptor while the other arguments are pointers to a flat [8] array.
Adding 'contiguous' yields

Error: 'add2vecs2' at (1) has the CONTIGUOUS attribute but is not an array
pointer or an assumed-shape or assumed-rank array

so maybe it's really just a missed optimization in the Frontend?

  reply	other threads:[~2021-09-28  8:54 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-28  2:17 [Bug fortran/102510] New: Function call has unnecessary aliasing check dwwork at gmail dot com
2021-09-28  8:54 ` rguenth at gcc dot gnu.org [this message]
2021-09-28 13:55 ` [Bug fortran/102510] Function call has unnecessary stride check dwwork at gmail dot com
2021-09-28 19:03 ` anlauf at gcc dot gnu.org
2021-09-28 19:26 ` dwwork at gmail dot com
2021-09-29 21:01 ` anlauf at gcc dot gnu.org

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