[Openmp-dev] [LLVMdev] OpenMP 3.1 Implementation Complete

Jack Howarth howarth.mailing.lists at gmail.com
Wed May 13 07:42:06 PDT 2015 

On Wed, May 13, 2015 at 10:03 AM, Jack Howarth
<howarth.mailing.lists at gmail.com> wrote:
> On Wed, May 13, 2015 at 9:24 AM, Bataev, Alexey <a.bataev at hotmail.com> wrote:
>> Jack, this is not a problem of this patch, this a problem of your
>> configuration. This patch uses standard clang machinery for locating t
>> libiomp5 library.
>>
>> Best regards,
>> Alexey Bataev
>> =============
>> Software Engineer
>> Intel Compiler Team
>>
>

Andrey,
    I would also note that libc++ is an odd duck since AFAIK in-tree
builds of libc++ are still discouraged so it tends to be built and
installed independently of the rest of the llvm build tree, Outside of
libc++, clang currently only expects to find shared libraries from the
llvm cmake build in the lib/clang/3.7.0/lib/darwin subdiirectory. So
openmp actually is the first shared library (used by a clang compiler
option) which is installed outside of the lib/clang/3.7.0/lib/darwin
subdirectory. Again this isn't a defect in the -fopenmp patch but
rather a deficiency in the current clang library search path vs the
possible install locations used with the CMAKE_INSTALL_PREFIX cmake
option.
               Jack

> Andrey,
>      I disagree in that currently the clang machinery only expects to
> have to look in the subdirectory lib/clang/3.7.0/lib/darwin for shared
> libraries. Considering that libc++ is the only other shared library in
> llvm which clang had to track in the past, this issue hasn't really
> been addressed in the past. It is clearly wrong for clang to allow
> libiomp5.dylib to be installed in a buried subdirectory using the
> CMAKE_INSTALL_PREFIX cmake option which clang then doesn't know about
> when attempting to link -liomp5. I am not saying the patch itself is
> flawed but rather than there needs to be a discussion about the
> expected search path for libraries in clang vs the installed locations
> of libiomp5. Currently we have a gap where the CMAKE_INSTALL_PREFIX
> cmake option allows libiomp5.dylib to be installed in a location that
> clang is unaware of which is clearly broken behavior.
>              Jack
>
>>
>>> On Tue, May 12, 2015 at 3:58 PM,  <andreybokhanko at gmail.com> wrote:
>>>>
>>>> Jack,
>>>>
>>>> Alexey [Bataev] promised to send it for review in a day or two. Then it
>>>> should be approved by code reviewers, which might take some time.
>>>>
>>>> andrey
>>>
>>> Andrey,
>>>         There is one issue with the proposed patch at
>>>
>>> http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20150511/129075.html
>>> with regard to finding the installed libiomp5.dylib for linkage. If
>>> the cmake build of llvm/clang/opemmp uses
>>> -DCMAKE_INSTALL_PREFIX=/sw/opt/llvm-3.7, the -fopenmp option fails to
>>> find the libiomp5.dylib installed in /sw/opt/llvm-3.7/lib for
>>> linkage...
>>>
>>> % clang-3.7 -fopenmp -o omp_getEnvInfo omp_getEnvInfo.c -v
>>> clang version 3.7.0 (trunk)
>>> Target: x86_64-apple-darwin14.4.0
>>> Thread model: posix
>>>   "/sw/opt/llvm-3.7.0/bin/clang-3.7" -cc1 -triple
>>> x86_64-apple-macosx10.10.0 -emit-obj -mrelax-all -disable-free
>>> -disable-llvm-verifier -main-file-name omp_getEnvInfo.c
>>> -mrelocation-model pic -pic-level 2 -mthread-model posix
>>> -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2
>>> -target-linker-version 242 -v -dwarf-column-info
>>> -fno-unique-section-names -resource-dir
>>> /sw/opt/llvm-3.7.0/bin/../lib/clang/3.7.0 -fdebug-compilation-dir
>>> /Users/howarth/openmp_examples -ferror-limit 19 -fmessage-length 140
>>> -fopenmp -stack-protector 1 -mstackrealign -fblocks
>>> -fobjc-runtime=macosx-10.10.0 -fencode-extended-block-signature
>>> -fmax-type-align=16 -fdiagnostics-show-option -fcolor-diagnostics -o
>>> /var/folders/1l/n78sywl52lz6kkys6nv7mnph0000gp/T/omp_getEnvInfo-e20595.o
>>> -x c omp_getEnvInfo.c
>>> clang -cc1 version 3.7.0 based upon LLVM 3.7.0svn default target
>>> x86_64-apple-darwin14.4.0
>>> ignoring nonexistent directory "/usr/local/include"
>>> #include "..." search starts here:
>>> #include <...> search starts here:
>>>   /sw/opt/llvm-3.7.0/bin/../lib/clang/3.7.0/include
>>>   /usr/include
>>>   /System/Library/Frameworks (framework directory)
>>>   /Library/Frameworks (framework directory)
>>> End of search list.
>>>   "/sw/opt/llvm-3.7.0/bin/ld" -demangle -dynamic -arch x86_64
>>> -macosx_version_min 10.10.0 -o omp_getEnvInfo -liomp5
>>> /var/folders/1l/n78sywl52lz6kkys6nv7mnph0000gp/T/omp_getEnvInfo-e20595.o
>>> -lSystem
>>> ld: library not found for -liomp5
>>> clang-3.7: error: linker command failed with exit code 1 (use -v to
>>> see invocation)
>>>
>>> The location of the installed libiomp5.dylib should always be in the
>>> default library search path for the clang compilers.
>>>                   Jack
>>>
>>>> Отправлено с iPad
>>>>
>>>>> 12 мая 2015 г., в 21:22, Jack Howarth <howarth.mailing.lists at gmail.com>
>>>>> написал(а):
>>>>>
>>>>> Andrey,
>>>>>      Any idea when the patch to enable openmp as the default for
>>>>> -fopenmp will be posted to cfe-commits?
>>>>>                 Jack
>>>>>
>>>>> On Fri, May 8, 2015 at 4:10 PM, Andrey Bokhanko
>>>>> <andreybokhanko at gmail.com> wrote:
>>>>>>
>>>>>> No, just changing defaults -- subject to code reviewers approval.
>>>>>>
>>>>>> As I said before, I prefer to leave library naming to library pros.
>>>>>>
>>>>>> Andrey
>>>>>>
>>>>>>
>>>>>> On Fri, May 8, 2015 at 7:21 PM, Jack Howarth
>>>>>> <howarth.mailing.lists at gmail.com> wrote:
>>>>>>>
>>>>>>> So you plan on switching and enabling the openmp library defaults as
>>>>>>> well as changing the openmp library name at the same time?
>>>>>>>         Jack
>>>>>>>
>>>>>>> On Fri, May 8, 2015 at 12:04 PM, andreybokhanko
>>>>>>> <andreybokhanko at gmail.com> wrote:
>>>>>>>>
>>>>>>>> It will come on next week.
>>>>>>>>
>>>>>>>> I'd like to give a chance to everyone to raise their objections
>>>>>>>> first.
>>>>>>>>
>>>>>>>> Yours,
>>>>>>>> Andrey
>>>>>>>>
>>>>>>>>> 8 мая 2015 г., в 18:30, Jack Howarth
>>>>>>>>> <howarth.mailing.lists at gmail.com> написал(а):
>>>>>>>>>
>>>>>>>>> Is there a proposed patch yet for switching the -fopenmp support
>>>>>>>>> over
>>>>>>>>> to the openmp library instead of libgomp? I realize the call to
>>>>>>>>> rename
>>>>>>>>> the library may be complicating this process. Perhaps the switch of
>>>>>>>>> the default library should be done first under the current libiomp5
>>>>>>>>> name and that tested for a few days first before using follow on
>>>>>>>>> patches to switch the library name to llomp or whatever. I would be
>>>>>>>>> nice to no longer have to feed clang "-fopenmp=libiomp5 -Xclang
>>>>>>>>> -fopenmp=libiomp5".
>>>>>>>>>           Jack
>>>>>>>>>
>>>>>>>>> On Fri, May 8, 2015 at 9:26 AM, Andrey Bokhanko
>>>>>>>>> <andreybokhanko at gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>> On Thu, May 7, 2015 at 10:53 PM, Hans Wennborg <hans at chromium.org>
>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>> Congratulations! Would you like to add a blurb to the release
>>>>>>>>>>> notes
>>>>>>>>>>> for the next release?
>>>>>>>>>>
>>>>>>>>>> Sure! Will do.
>>>>>>>>>>
>>>>>>>>>> Yours,
>>>>>>>>>> Andrey
>>>>>>>>>> _______________________________________________
>>>>>>>>>> Openmp-dev mailing list
>>>>>>>>>> Openmp-dev at dcs-maillist2.engr.illinois.edu
>>>>>>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/openmp-dev
>>
>>

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