From: Iain Sandoe <idsandoe@googlemail.com>
To: Thomas Koenig <tkoenig@netcologne.de>
Cc: Jakub Jelinek <jakub@redhat.com>,
Michael Meissner <meissner@linux.ibm.com>,
Paul Thomas <pault@gcc.gnu.org>,
Segher Boessenkool <segher@kernel.crashing.org>,
GCC Development <gcc@gcc.gnu.org>,
fortran@gcc.gnu.org, Tobias Burnus <tobias@codesourcery.com>
Subject: Re: libgfortran.so SONAME and powerpc64le-linux ABI changes
Date: Sat, 9 Oct 2021 00:18:31 +0100 [thread overview]
Message-ID: <C8477E9D-176D-4D7C-9EE8-421D23768DAA@googlemail.com> (raw)
In-Reply-To: <e6004e4f-ed78-9e0b-8b84-6782d28c2338@netcologne.de>
> On 8 Oct 2021, at 23:55, Thomas Koenig via Gcc <gcc@gcc.gnu.org> wrote:
>
>
> Hi Iain,
>
>>> Things get interesting for user code, calling a routine compiled
>>> for double double with newer IEEE QP will result in breakage.
>> That would not happen with the proposal above, since the library would
>> have different entry points for the two formats.
>
> I meant the case where the user writes, with an old, KIND=16 is double
> double compiler,
>
> subroutine foo(a)
> real(kind=16) :: a
> a = a + 1._16
> end subroutine foo
>
> and puts it in a library or an old object file, and in new code with an
> IEEE QP compiler calls that with
>
> real(kind=16) :: a
> a = 2._16
> call foo(a)
> print *,a
>
> this will result in silent generation of garbage values, since Fortran
> does not mangle the function name based on it types. For both cases, the
> subroutine will be called foo_ (or MOD..._foo).
hmm, well I thought about that case, but … isn’t this “pilot error”?
if one compiles different parts of a project with incompatible command line options…
… or, say, compile with -mavx512 and then try to run code on hardware without
such a vector unit?
Getting wrong answers silently can likely be done with other command line
option mismatches.
Iain
> There is no choice - we need to make object code compiled by the user
> incompatible between the old and the new format on the systems where
> we make the switch.
>
> This is starting to look like a can of worms from Pandora's box,
> if you pardon my mixed metaphors.
>
> Best regards
>
> Thomas
next prev parent reply other threads:[~2021-10-08 23:18 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-04 10:07 Jakub Jelinek
2021-10-04 11:24 ` Richard Biener
2021-10-04 11:36 ` Jakub Jelinek
2021-10-04 12:31 ` Jakub Jelinek
2021-10-04 14:14 ` Jakub Jelinek
2021-10-04 16:47 ` Joseph Myers
2021-10-04 18:33 ` Segher Boessenkool
2021-10-04 19:24 ` Joseph Myers
2021-10-05 17:43 ` Segher Boessenkool
2021-10-14 19:39 ` Bill Schmidt
2021-10-15 0:26 ` Segher Boessenkool
2021-10-05 20:16 ` Thomas Koenig
2021-10-05 21:54 ` Segher Boessenkool
2021-10-06 6:59 ` Thomas Koenig
2021-10-06 15:17 ` Segher Boessenkool
2021-10-06 15:41 ` Jakub Jelinek
2021-10-06 16:07 ` Segher Boessenkool
2021-10-06 16:34 ` Jakub Jelinek
2021-10-06 16:59 ` Segher Boessenkool
2021-10-06 17:07 ` Jakub Jelinek
2021-10-06 17:50 ` Segher Boessenkool
2021-10-06 19:30 ` Peter Bergner
2021-10-06 17:13 ` Joseph Myers
2021-10-06 18:39 ` Segher Boessenkool
2021-10-06 19:42 ` Joseph Myers
2021-10-06 20:57 ` Segher Boessenkool
2021-10-06 21:55 ` Joseph Myers
2021-10-06 22:03 ` Joseph Myers
2021-10-08 17:53 ` Segher Boessenkool
2021-10-11 20:11 ` Joseph Myers
2021-10-15 0:16 ` Segher Boessenkool
2021-10-06 15:42 ` David Edelsohn
2021-10-06 16:19 ` Segher Boessenkool
2021-10-06 17:38 ` David Edelsohn
2021-10-07 3:42 ` Michael Meissner
2021-10-08 21:10 ` Segher Boessenkool
2021-10-07 9:48 ` Alastair McKinstry
2021-10-07 9:56 ` Andreas Schwab
2021-10-07 10:01 ` Jakub Jelinek
2021-10-07 12:43 ` Alastair McKinstry
2021-10-05 21:53 ` Jonathan Wakely
2021-10-07 3:35 ` Michael Meissner
2021-10-07 6:08 ` Thomas Koenig
2021-10-07 9:40 ` Jakub Jelinek
2021-10-07 15:24 ` Michael Meissner
2021-10-07 15:33 ` Jakub Jelinek
2021-10-08 6:35 ` Thomas Koenig
2021-10-08 7:20 ` Iain Sandoe
2021-10-08 16:26 ` Thomas Koenig
2021-10-08 19:11 ` Iain Sandoe
2021-10-08 22:55 ` Thomas Koenig
2021-10-08 23:18 ` Iain Sandoe [this message]
2021-10-09 9:11 ` Thomas Koenig
2021-10-09 9:19 ` Iain Sandoe
2021-10-09 9:25 ` Jakub Jelinek
2021-10-09 7:44 ` Andreas Schwab
2021-10-10 16:14 ` Florian Weimer
2021-10-15 13:50 ` Bill Schmidt
2021-10-15 14:20 ` Jakub Jelinek
2021-10-15 18:05 ` Thomas Koenig
2021-10-15 18:11 ` Jakub Jelinek
2021-10-15 18:58 ` Thomas Koenig
2021-10-15 22:24 ` Segher Boessenkool
2021-10-15 22:36 ` Segher Boessenkool
2021-10-18 19:02 ` Joseph Myers
2021-10-28 3:10 ` Michael Meissner
2021-10-29 3:36 ` libgfortran.so SONAME and powerpc64le-linux ABI changes (work in progress patches) Michael Meissner
2021-10-29 19:07 ` Thomas Koenig
2021-10-29 21:06 ` Michael Meissner
2021-11-01 15:56 ` Bill Schmidt
2021-11-02 15:40 ` Michael Meissner
2021-10-30 0:16 ` libgfortran.so SONAME and powerpc64le-linux ABI changes (2nd patch) Michael Meissner
2021-10-30 9:30 ` Thomas Koenig
2021-10-30 10:03 ` Jakub Jelinek
2021-10-30 10:31 ` Thomas Koenig
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