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From: "burnus at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/107424] [13/14 Regression] ICE in gfc_trans_omp_do, at fortran/trans-openmp.cc:5397 - and wrong code - with non-rectangular loops
Date: Mon, 17 Jul 2023 11:15:32 +0000	[thread overview]
Message-ID: <bug-107424-4-Q971kCU3j4@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107424-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107424

--- Comment #14 from Tobias Burnus <burnus at gcc dot gnu.org> ---
(In reply to Tobias Burnus from comment #12)
> Handle loop steps other than ±1.

Fortran (here F2023) has under "11.1.7.4.3 The execution cycle" (for "DO"):
"... consists of the following steps ..."
"(1) The iteration count, if any, is tested. If it is zero, the loop terminates
...
"(2) The block of the loop is executed.28
"(3) The iteration count, if any, is decremented by one. The DO variable, if
any, is incremented by the value of the incrementation parameter m3."

And Fortran states: "The execution of any numeric operation whose result is not
defined by the arithmetic used by the processor is prohibited." (10.1.5.2.4
Evaluation of numeric intrinsic operations).

* * *

Thus (cf. email linked in comment 12), simply extending this to any constant
step should be possible. (For the other cases, see email.)

  parent reply	other threads:[~2023-07-17 11:15 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-26 18:37 [Bug fortran/107424] New: [13 Regression] ICE in gfc_trans_omp_do, at fortran/trans-openmp.cc:5397 gscfq@t-online.de
2022-10-27  8:50 ` [Bug fortran/107424] " marxin at gcc dot gnu.org
2022-10-28 11:35 ` rguenth at gcc dot gnu.org
2023-01-11 15:30 ` [Bug fortran/107424] [13 Regression] ICE in gfc_trans_omp_do, at fortran/trans-openmp.cc:5397 - and wrong code - with non-rectangular loops burnus at gcc dot gnu.org
2023-01-11 15:59 ` burnus at gcc dot gnu.org
2023-01-13 10:46 ` burnus at gcc dot gnu.org
2023-01-13 10:53 ` burnus at gcc dot gnu.org
2023-01-13 11:07 ` jakub at gcc dot gnu.org
2023-01-13 11:46 ` burnus at gcc dot gnu.org
2023-01-13 11:51 ` jakub at gcc dot gnu.org
2023-01-18 22:24 ` burnus at gcc dot gnu.org
2023-01-25 14:50 ` burnus at gcc dot gnu.org
2023-02-09 14:51 ` cvs-commit at gcc dot gnu.org
2023-02-09 14:54 ` burnus at gcc dot gnu.org
2023-04-26  6:56 ` [Bug fortran/107424] [13/14 " rguenth at gcc dot gnu.org
2023-07-17 11:15 ` burnus at gcc dot gnu.org [this message]
2023-07-19  8:19 ` cvs-commit at gcc dot gnu.org
2023-07-19  8:27 ` burnus at gcc dot gnu.org

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