Given that the Cray compiler aborts on this code with an incorrect error message, I would actually call it a compiler bug. The compiler may possibly want to complain that it doesn't know __builtin_ffsl, but its error message (Declaration is incompatible with "int ffsl(long)") indicates that there is some other problem. Note that hwloc never declares ffsl; it only calls __builtin_ffsl.
However, I have a work-around, and leave it up to you to report this or not. -erik On Thu, Jan 17, 2013 at 2:40 PM, Jeff Hammond <jhamm...@alcf.anl.gov> wrote: > Well then, this is most certainly not a Cray bug :-) The compiler is > doing exactly what you asked it to do. > > I would configure hwloc without this flag and assume that this > resolves the issue. > > Jeff > > On Thu, Jan 17, 2013 at 1:27 PM, Erik Schnetter <schnet...@cct.lsu.edu> > wrote: > > I realise I did not mention the flags I used when configuring hwloc. I am > > using > > > > -g -h gnu -O3 > > > > which explicitly asks to recognise GNU extensions. (I need to use -h gnu > to > > compile certain other code.) This would explain why __GNUC__ is > defined... > > Apologies for omitting this earlier. > > > > -erik > > > > > > > > On Thu, Jan 17, 2013 at 2:21 PM, Jeff Hammond <jhamm...@alcf.anl.gov> > wrote: > >> > >> 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 <schnet...@cct.lsu.edu> > >> 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.gog...@inria.fr> > >> > 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 <jhamm...@alcf.anl.gov> 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 < > schnet...@gmail.com> > >> >>> 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 <schnet...@gmail.com> > >> >>>> http://www.perimeterinstitute.ca/personal/eschnetter/ > >> >>>> > >> >>>> > >> >>>> ________________________________ > >> >>>> > >> >>>> hwloc-users mailing list > >> >>>> hwloc-us...@open-mpi.org > >> >>>> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users > >> >>> > >> >>> > >> >>> > >> >> > >> >> _______________________________________________ > >> >> > >> >> hwloc-users mailing list > >> >> hwloc-us...@open-mpi.org > >> >> http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users > >> > > >> > > >> > > >> > > >> > -- > >> > Erik Schnetter <schnet...@cct.lsu.edu> > >> > http://www.perimeterinstitute.ca/personal/eschnetter/ > >> > >> > >> > >> -- > >> Jeff Hammond > >> Argonne Leadership Computing Facility > >> University of Chicago Computation Institute > >> jhamm...@alcf.anl.gov / (630) 252-5381 > >> http://www.linkedin.com/in/jeffhammond > >> https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond > > > > > > > > > > -- > > Erik Schnetter <schnet...@cct.lsu.edu> > > http://www.perimeterinstitute.ca/personal/eschnetter/ > > > > -- > Jeff Hammond > Argonne Leadership Computing Facility > University of Chicago Computation Institute > jhamm...@alcf.anl.gov / (630) 252-5381 > http://www.linkedin.com/in/jeffhammond > https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond > -- Erik Schnetter <schnet...@cct.lsu.edu> http://www.perimeterinstitute.ca/personal/eschnetter/
