[Fortran, Patch] First patch for coarray FAILED IMAGES (TS 18508)
Damian Rouson
damian@sourceryinstitute.org
Wed Jan 18 06:42:00 GMT 2017
Resending as plain text:
*PING*
With the 7.1.0 deadline approaching tomorrow, is there any chance of getting Alessandro’s FAILED IMAGES patch approved for trunk? As far as I know, Fortran is the first internationally standardized language to incorporate intrinsic support for fault tolerance, which is believed to be essential to reaching exaflop performance. As far as I know, gfortran is the first compiler to implement this Fortran 2015 feature. This is a huge deal and I’m hoping Alessandro and I will be able to report that this is a released feature in a talk we’re giving jointly in early February. Any assistance would be greatly appreciated.
Damian
> Begin forwarded message:
>
>
> From: Alessandro Fanfarillo <fanfarillo.gcc@gmail.com>
> Subject: Re: [Fortran, Patch] First patch for coarray FAILED IMAGES (TS 18508)
> Date: September 21, 2016 at 11:03:48 AM PDT
> To: Andre Vehreschild <vehre@gmx.de>
> Cc: Paul Richard Thomas <paul.richard.thomas@gmail.com>, gfortran <fortran@gcc.gnu.org>, gcc-patches <gcc-patches@gcc.gnu.org>, Mikael Morin <morin-mikael@orange.fr>, Tobias Burnus <burnus@net-b.de>
>
>
> Thanks Andre.
>
> 2016-09-19 9:55 GMT-06:00 Andre Vehreschild <vehre@gmx.de>:
>> Hi Alessandro,
>
>> The if in resolve.c at 8837: resolve_failed_image (... is intentional? It is
>> doing nothing. So do you plan to add more code, or will there never be
>> anything. If the later I recommend to just put a comment there and remove the
>> empty if.
>
> I added the if statement during the development and I forgot to remove it.
>
>>
>> There still is no test when -fcoarray=single is used. This shouldn't be so
>> hard, should it?
>
> Done.
>
> Built and regtested on x86_64-pc-linux-gnu.
>
>>
>> Regards,
>> Andre
>>
>> On Mon, 19 Sep 2016 08:30:12 -0700
>> Alessandro Fanfarillo <fanfarillo.gcc@gmail.com> wrote:
>>
>>> * PING *
>>>
>>> On Sep 7, 2016 3:01 PM, "Alessandro Fanfarillo" <fanfarillo.gcc@gmail.com>
>>> wrote:
>>>
>>>> Dear all,
>>>> the attached patch supports failed images also when -fcoarray=single is
>>>> used.
>>>>
>>>> Built and regtested on x86_64-pc-linux-gnu.
>>>>
>>>> Cheers,
>>>> Alessandro
>>>>
>>>> 2016-08-09 5:22 GMT-06:00 Paul Richard Thomas <
>>>> paul.richard.thomas@gmail.com>:
>>>>> Hi Sandro,
>>>>>
>>>>> As far as I can see, this is OK barring a couple of minor wrinkles and
>>>>> a question:
>>>>>
>>>>> For coarray_failed_images_err.f90 and coarray_image_status_err.f90 you
>>>>> have used the option -fdump-tree-original without making use of the
>>>>> tree dump.
>>>>>
>>>>> Mikael asked you to provide an executable test with -fcoarray=single.
>>>>> Is this not possible for some reason?
>>>>>
>>>>> Otherwise, this is OK for trunk.
>>>>>
>>>>> Thanks for the patch.
>>>>>
>>>>> Paul
>>>>>
>>>>> On 4 August 2016 at 05:07, Alessandro Fanfarillo
>>>>> <fanfarillo.gcc@gmail.com> wrote:
>>>>>> * PING *
>>>>>>
>>>>>> 2016-07-21 13:05 GMT-06:00 Alessandro Fanfarillo <
>>>> fanfarillo.gcc@gmail.com>:
>>>>>>> Dear Mikael and all,
>>>>>>>
>>>>>>> in attachment the new patch, built and regtested on
>>>> x86_64-pc-linux-gnu.
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Alessandro
>>>>>>>
>>>>>>> 2016-07-20 13:17 GMT-06:00 Mikael Morin <morin-mikael@orange.fr>:
>>>>>>>> Le 20/07/2016 à 11:39, Andre Vehreschild a écrit :
>>>>>>>>>
>>>>>>>>> Hi Mikael,
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>>> + if(st == ST_FAIL_IMAGE)
>>>>>>>>>>> + new_st.op = EXEC_FAIL_IMAGE;
>>>>>>>>>>> + else
>>>>>>>>>>> + gcc_unreachable();
>>>>>>>>>>
>>>>>>>>>> You can use
>>>>>>>>>> gcc_assert (st == ST_FAIL_IMAGE);
>>>>>>>>>> foo...;
>>>>>>>>>> instead of
>>>>>>>>>> if (st == ST_FAIL_IMAGE)
>>>>>>>>>> foo...;
>>>>>>>>>> else
>>>>>>>>>> gcc_unreachable ();
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Be careful, this is not 100% identical in the general case. For older
>>>>>>>>> gcc version (gcc < 4008) gcc_assert() is mapped to nothing, esp. not
>>>> to
>>>>>>>>> an abort(), so the behavior can change. But in this case everything
>>>> is
>>>>>>>>> fine, because the patch is most likely not backported.
>>>>>>>>>
>>>>>>>> Didn't know about this. The difference seems to be very subtle.
>>>>>>>> I don't mind much anyway. The original version can stay if preferred,
>>>> this
>>>>>>>> was just a suggestion.
>>>>>>>>
>>>>>>>> By the way, if the function is inlined in its single caller, the
>>>> assert or
>>>>>>>> unreachable statement can be removed, which avoids choosing between
>>>> them.
>>>>>>>> That's another suggestion.
>>>>>>>>
>>>>>>>>
>>>>>>>>>>> +
>>>>>>>>>>> + return MATCH_YES;
>>>>>>>>>>> +
>>>>>>>>>>> + syntax:
>>>>>>>>>>> + gfc_syntax_error (st);
>>>>>>>>>>> +
>>>>>>>>>>> + return MATCH_ERROR;
>>>>>>>>>>> +}
>>>>>>>>>>> +
>>>>>>>>>>> +match
>>>>>>>>>>> +gfc_match_fail_image (void)
>>>>>>>>>>> +{
>>>>>>>>>>> + /* if (!gfc_notify_std (GFC_STD_F2008_TS, "FAIL IMAGE statement
>>>>>>>>>>> at %C")) */
>>>>>>>>>>> + /* return MATCH_ERROR; */
>>>>>>>>>>> +
>>>>>>>>>>
>>>>>>>>>> Can this be uncommented?
>>>>>>>>>>
>>>>>>>>>>> + return fail_image_statement (ST_FAIL_IMAGE);
>>>>>>>>>>> +}
>>>>>>>>>>>
>>>>>>>>>>> /* Match LOCK/UNLOCK statement. Syntax:
>>>>>>>>>>> LOCK ( lock-variable [ , lock-stat-list ] )
>>>>>>>>>>> diff --git a/gcc/fortran/trans-intrinsic.c
>>>>>>>>>>> b/gcc/fortran/trans-intrinsic.c index 1aaf4e2..b2f5596 100644
>>>>>>>>>>> --- a/gcc/fortran/trans-intrinsic.c
>>>>>>>>>>> +++ b/gcc/fortran/trans-intrinsic.c
>>>>>>>>>>> @@ -1647,6 +1647,24 @@ trans_this_image (gfc_se * se, gfc_expr
>>>>>>>>>>> *expr) m, lbound));
>>>>>>>>>>> }
>>>>>>>>>>>
>>>>>>>>>>> +static void
>>>>>>>>>>> +gfc_conv_intrinsic_image_status (gfc_se *se, gfc_expr *expr)
>>>>>>>>>>> +{
>>>>>>>>>>> + unsigned int num_args;
>>>>>>>>>>> + tree *args,tmp;
>>>>>>>>>>> +
>>>>>>>>>>> + num_args = gfc_intrinsic_argument_list_length (expr);
>>>>>>>>>>> + args = XALLOCAVEC (tree, num_args);
>>>>>>>>>>> +
>>>>>>>>>>> + gfc_conv_intrinsic_function_args (se, expr, args, num_args);
>>>>>>>>>>> +
>>>>>>>>>>> + if (flag_coarray == GFC_FCOARRAY_LIB)
>>>>>>>>>>> + {
>>>>>>>>>>
>>>>>>>>>> Can everything be put under the if?
>>>>>>>>>> Does it work with -fcoarray=single?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> IMO coarray=single should not generate code here, therefore putting
>>>>>>>>> everything under the if should to fine.
>>>>>>>>>
>>>>>>>> My point was more avoiding generating code for the arguments if they
>>>> are not
>>>>>>>> used in the end.
>>>>>>>> Regarding the -fcoarray=single case, the function returns a result,
>>>> which
>>>>>>>> can be used in an expression, so I don't think it will work without
>>>> at least
>>>>>>>> hardcoding a fixed value as result in that case.
>>>>>>>> But even that wouldn't be enough, as the function wouldn't work
>>>> consistently
>>>>>>>> with the fail image statement.
>>>>>>>>
>>>>>>>>> Sorry for the comments ...
>>>>>>>>>
>>>>>>>> Comments are welcome here, as far as I know. ;-)
>>>>>>>>
>>>>>>>> Mikael
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> The difference between genius and stupidity is; genius has its limits.
>>>>>
>>>>> Albert Einstein
>>>>
>>
>>
>> --
>> Andre Vehreschild * Email: vehre ad gmx dot de
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