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Subject: Re: [hwloc-users] hwloc-1.6.1rc2 Build failure with Cray compiler
From: Jeff Hammond (jhammond_at_[hidden])
Date: 2013-01-17 14:21:26


I was not able to reproduce the behavior described by Erik on the
NERSC Cray XE6, which is to say, Cray C does not claim to be GCC
there. As I can't verify the problem, I can't report it.

I have no experience with Cray bug fix latency but I suspect this
needs to be worked-around (I refuse to call it a fix since there is no
problem in hwloc) because Cray won't backport whatever fix they
implement to all their compilers that users might come across.

Jeff

On Thu, Jan 17, 2013 at 1:15 PM, Erik Schnetter <schnetter_at_[hidden]> wrote:
> I have no idea how fast Cray acts in such a case.
>
> -erik
>
>
> On Thu, Jan 17, 2013 at 2:05 PM, Brice Goglin <brice.goglin_at_[hidden]> wrote:
>>
>> Does Cray fix such bugs quickly usually? If so, no need to change hwloc.
>> If not, I'll need somebody to test the change on other cray platforms and
>> compiler versions.
>> Brice
>>
>>
>>
>> Jeff Hammond <jhammond_at_[hidden]> a écrit :
>>>
>>> This is a bug in the Cray compiler. They cannot and should not set
>>> the __GNUC__ flag unless they are fully compatible with GCC. There
>>>
>>> are many ways to define "fully compatible" but at a minimum, code that
>>> compiles with GCC needs to compile with any compiler that elects to
>>> define __GNUC__. It is prudent to impose a higher standard in some
>>>
>>> cases but that's not pertinent to this discussion.
>>>
>>> Lots of vendor compilers pretend to be __GNUC__ for any number of
>>> reasons. I believe that they are all wrong for doing it.
>>>
>>> Regarding this specific issue, there is nothing wrong with hwloc and I
>>>
>>> don't know why anyone should bother trying to fix Cray's problem, but
>>> I suspect that pragmatism will prevail, as it appears to have in the
>>> case of Boost
>>> (http://www.boost.org/doc/libs/1_52_0/boost/config/select_platform_config.hpp).
>>>
>>>
>>> I'll reproduce this locally and contact Cray directly about fixing
>>> this on their end.
>>>
>>> Best,
>>>
>>> Jeff
>>>
>>> On Thu, Jan 17, 2013 at 12:19 PM, Erik Schnetter <schnetter_at_[hidden]>
>>> wrote:
>>>
>>>> hwloc-1.6.1rc2 fails to build with the Cray compiler
>>>>
>>>> Cray C : Version 8.1.2 Thu Jan 17, 2013 12:18:54
>>>>
>>>>
>>>> The error message is
>>>>
>>>> CC bitmap.lo
>>>> CC-147 craycc: ERROR
>>>> Declaration is incompatible with "int ffsl(long)" (declared at line 526
>>>> of
>>>> "/opt/cray/xe-sysroot/4.1.20/usr/include/string.h").
>>>>
>>>>
>>>> (Yes, there is no line number with the error message.)
>>>>
>>>> This seems to be caused by the fact that the Cray c!
>>>> ompiler
>>>> sets __GNUC__,
>>>>
>>>> but is not quite compatible. A work-around is to change line 56 of
>>>> include/private/misc.h from
>>>>
>>>> #elif defined(__GNUC__)
>>>>
>>>> to
>>>>
>>>> #elif defined(__GNUC__) && !defined(_CRAYC)
>>>>
>>>>
>>>> -erik
>>>>
>>>> --
>>>> Erik Schnetter <schnetter_at_[hidden]>
>>>> http://www.perimeterinstitute.ca/personal/eschnetter/
>>>>
>>>>
>>>> ________________________________
>>>>
>>>> hwloc-users mailing list
>>>> hwloc-users_at_[hidden]
>>>> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users
>>>
>>>
>>>
>>
>> _______________________________________________
>>
>> hwloc-users mailing list
>> hwloc-users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users
>
>
>
>
> --
> Erik Schnetter <schnetter_at_[hidden]>
> http://www.perimeterinstitute.ca/personal/eschnetter/

-- 
Jeff Hammond
Argonne Leadership Computing Facility
University of Chicago Computation Institute
jhammond_at_[hidden] / (630) 252-5381
http://www.linkedin.com/in/jeffhammond
https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond