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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug fortran/102510] Function call has unnecessary stride check
Date: Tue, 28 Sep 2021 08:54:18 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102510

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 resu=
lt
is one and thus we version on that.  I'm not sure whether fortran allows

  res(/1, 16, 2/) =3D 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?=