Seems like -O5 is available on Community Edition, actually.
On Tue, Dec 20, 2016 at 2:29 PM, James Ostrander <jlost.umich.edu> wrote:
> Sorry for the late reply, Jason.
>
> The XL compilers actually have a free community edition available here:
> http://www.ibm.com/developerworks/downloads/r/xlcpluslinux/. Registration
> is required and it is a "community edition," but IIRC the only difference
> is that -O5 is unavailable.
>
> There is also a Docker image containing the compilers: https://hub.docker.
> com/r/ppc64le/xlc-ce/?cm_mc_uid=45583402832214744618583&
> cm_mc_sid_50200000=1482261441
> This could be used to set up a build bot if you were so inclined.
>
> Since XL compiler flags are different than GCC's, I don't think that
> proper support can be attained in less-maintenance-cumbersome way than the
> addition of a new compiler option in the build system. But let me know if
> you change your mind and I will submit the patch to you if/when it is made.
>
> On Wed, Dec 14, 2016 at 1:14 AM, Jason Swails <jason.swails.gmail.com>
> wrote:
>
>> On Tue, Dec 13, 2016 at 3:52 PM, James Ostrander <jlost.umich.edu> wrote:
>>
>> > Hi, I am trying to use AmberTools on an IBM POWER8 system (ppc64le).
>> IBM's
>> > compilers produce the fastest machine code for this system, so I always
>> try
>> > to use them first.
>> >
>> > AmberTools seems to have no direct support for the IBM XL compilers
>> > although it does offer out-of-the-box options for Intel, Clang, etc. I
>> also
>> > had a quick look at the build system and it seems non-trivial to
>> manually
>> > configure or add your own (unless I'm just missing something!).
>> >
>> > So from there, I have a few questions:
>> > - I didn't see any options in configure --full-help that suggested a
>> direct
>> > compiler override. Am I missing something?
>> > - If not, are there any plans to support IBM's compilers?
>> > - If not, and someone offered you a patch that added support, would you
>> be
>> > willing to accept it into the official codebase?
>> > - If so, is there any specific guidance you can offer that would get
>> > someone started on adding the support?
>> >
>>
>> ​You can always try to configure Amber (I would suggest using the
>> --with-netcdf flag and use a pre-built NetCDF library if possible) and
>> specify the gnu compilers. Then replace the compiler binaries in config.h
>> with the IBM compiler names (and replace compiler flags if necessary). If
>> the IBM compilers have flags compatible with another supported compiler,
>> then you may be able to set the CC, FC, and CXX environment variables to
>> point at the IBM compilers while specifying the flag-compatible compiler
>> suite to configure.
>>
>> Note that these compilers are not supported because developers do not have
>> access to these compilers. And adding support is only a relatively small
>> part of the job -- the much bigger part is maintaining that support
>> through
>> multiple versions of the various libraries, codes, and compiler versions.
>> It can sometimes be better to not have a feature at all than have some
>> untested code that *might* provide support.
>>
>> That's not to say there's no value, though. If there are small changes
>> necessary to improve IBM compiler support​
>>
>> that also improves the configure script as a whole (and does not introduce
>> maintenance headaches), I imagine such a patch would be welcome.
>>
>> HTH,
>> Jason
>>
>>
>> --
>> Jason M. Swails
>> _______________________________________________
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>> AMBER.ambermd.org
>> http://lists.ambermd.org/mailman/listinfo/amber
>>
>
>
>
> --
> *James Ostrander*
> *ITS Administrative Info Srvcs*
>
--
*James Ostrander*
*ITS Administrative Info Srvcs*
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Received on Tue Dec 20 2016 - 12:00:02 PST
