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From: "anlauf at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/107968] array slicing gives wrong result for an array pointer defined in a subroutine
Date: Mon, 05 Dec 2022 19:12:22 +0000	[thread overview]
Message-ID: <bug-107968-4-DC3xndnqL6@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107968-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107968

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-12-05
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |anlauf at gcc dot gnu.org

--- Comment #1 from anlauf at gcc dot gnu.org ---
Confirmed.

A look at the tree dump shows a funny expansion of the array section in
the data transfer (write statement).  It appears that some optimization
of the transfer of arrays is attempted, but the stride looks wrong.

Replacing

  WRITE (0,*) vertices_pointer%vlon(1:)

by any of the following produces different - working - output:

  WRITE (0,*) [vertices_pointer%vlon(1:)]
  WRITE (0,*) (vertices_pointer%vlon(1:))
  WRITE (0,*) (vertices_pointer%vlon(i),i=1,size(vertices_pointer%vlon))

And - as reported - why should the addition of a (dead) pointer assignment
after the write change the way the array section is expanded?

Looking at older gfortran version, all tested seem to fail.
And with the dead pointer assignment uncommented, gfortran-7 ICEs.

  reply	other threads:[~2022-12-05 19:12 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-05  7:16 [Bug fortran/107968] New: " dreier at dkrz dot de
2022-12-05 19:12 ` anlauf at gcc dot gnu.org [this message]
2022-12-05 21:36 ` [Bug fortran/107968] " anlauf at gcc dot gnu.org

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