Re: [pocl-devel] MacOS and POCL challenges

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Ah, that makes sense now. Can you try doing the following?

export SDKROOT=$(xcrun --show-sdk-path)

(Note that the clang you are using and the one from conda that pocl is
using are two different things)

Isuru

On Fri, May 20, 2022 at 10:41 AM Noah Reddell <noa...@gm...>
wrote:

> Hi Isuru,
>     Thank you for maintaining the conda package and the suggestion.
>
> It is true I don't have the conda environment activated when building
> / running my large app.   I installed conda for the sole purpose of
> POCL and generally use homebrew for similar needs.   I'm not seeing
> any difference in build/run of hello-opencl whether I have conda
> activated or not.  SDKROOT is not set either way.
>
> Starting with a fresh shell:
> ----------------------------------------------
> Last login: Wed May 18 22:48:50 on ttys005
> noah@Spitzer ~ % clang -g -L/Users/noah/miniforge3/lib/
> -Wl,-rpath,/Users/noah/miniforge3/lib/  -lOpenCL
> /Users/noah/Downloads/hello_opencl.c
> noah@Spitzer ~ % ./a.out
> Num Platforms: 1
> platform[0] name: Portable Computing Language
> platform[0] Num Devices: 1
> device[0] name: pthread
> function definition may only have a distinct !dbg attachment
> i64 (i32)* @_Z13get_global_idj
> Computed '1024/1024' correct values!
> noah@Spitzer ~ % echo $SDKROOT
>
> noah@Spitzer ~ % source /Users/noah/miniforge3/etc/profile.d/conda.sh
> noah@Spitzer ~ % conda activate
> (base) noah@Spitzer ~ % echo $SDKROOT
>
> (base) noah@Spitzer ~ % clang -g -L/Users/noah/miniforge3/lib/
> -Wl,-rpath,/Users/noah/miniforge3/lib/  -lOpenCL
> /Users/noah/Downloads/hello_opencl.c
> (base) noah@Spitzer ~ % ./a.out
> Num Platforms: 1
> platform[0] name: Portable Computing Language
> platform[0] Num Devices: 1
> device[0] name: pthread
> function definition may only have a distinct !dbg attachment
> i64 (i32)* @_Z13get_global_idj
> Computed '1024/1024' correct values!
>
> (base) noah@Spitzer ~ % which clang
> /usr/bin/clang
> ----------------------------------------------
>
>
> I'll check out your build.sh recipe.    At first glance, it is not
> clear to me how you're dealing with the MacOS pthread not having
> pthread_barrier_t and related functions.  When I tried to build POCL
> last week, those pthread parts are needed.
>
> Cheers,
> -Noah
>
>
> On Fri, May 20, 2022 at 7:51 AM Isuru Fernando <is...@gm...> wrote:
> >
> > I think the issue is that you don't have the conda environment activated.
> > Activating the conda environment sets the SDKROOT env variable
> > so that clang can find the macOS SDK.
> >
> > I maintain the pocl conda package with some other maintainers. You
> > can find our build scripts at
> https://github.com/conda-forge/pocl-feedstock/blob/main/recipe/build.sh
> >
> > Isuru
> >
> > On Fri, May 20, 2022 at 9:38 AM Noah Reddell <
> noa...@gm...> wrote:
> >>
> >> Hi,
> >>    I upgraded to an M1 Pro Mac and found that MacOS's built-in OpenCL
> >> implementation no longer supports the CPU device.  The GPU is
> >> supported -- for now at least, but doesn't do fp64.
> >>   I'm very motivated to have a local OpenCL platform on my Mac that
> >> supports CPU device.  This is by far the most productive way for me to
> >> first debug and develop kernels versus GPU-based debugging or on
> >> remote systems.   So I return to POCL but for the first time trying to
> >> use it on a Mac.  I'm having struggles.  (latest releases MacOS
> >> 12.3.1, XCode 13.4)
> >>
> >> My problems trying to build and run the latest POCL are more complex,
> >> so I'll first mention a problem trying to use POCL acquired with the
> >> Conda package manager this week.   I can build and run a simple
> >> hello-world program with one kernel and it computes the right answers
> >> using POCL.
> >> OpenCL Devices Detected:
> >> Platform: Portable Computing Language
> >> Type: CPU, Name: pthread
> >>
> >>
> >> Unfortunately, when I run my large computational science application,
> >> I get a runtime error shortly after the first call to
> >> clEnqueueNDRangeKernel().  The function returns CL_SUCCESS, another
> >> thread raises SIGABRT, I assume after the following output:
> >>
> >> ld: dynamic main executables must link with libSystem.dylib for
> >> architecture arm64
> >> error: linker command failed with exit code 1 (use -v to see invocation)
> >> Final linking of kernel physical_initial_condition_evaluation failed.
> >>
> >> Since my hello-world app works, yet the app I care about doesn't,  my
> >> leading suspicion so far is some confusion about which clang / llvm is
> >> getting utilized.  I've tried to be careful about what PATH is set and
> >> I'm not setting DYLD_LIBRARY_PATH in any way.
> >> I'd love to pass "-v" to the POCL link as suggested, but I'm not sure
> >> how to do that.
> >> The main application *is* linked with -lSystem so that error message
> >> is probably referring to the POCL kernel build.
> >> It looks like POCL_MSG_PRINT_LLVM could be helpful, but I think that
> >> is only set when POCL is built, and I'm not able to build.
> >>
> >> Ok,  so any suggestions about the above problem would be appreciated!
> >>
> >>
> >> Sometime I'd really like to be able to build POCL myself.
> >>
> >> I can tell that some special steps are needed to get the latest POCL
> >> to build for MacOS.  Who is maintaining that Conda package?   Are the
> >> build steps available?
> >>
> >>    Lesser question stemming from my failed attempts to build POCL from
> source:
> >> Question:  What is the difference between the "basic" device and
> >> "pthread" device?  I'm not finding documentation for either host
> >> devices.
> >>    One reason I ask is that I found problems building "pthread" due to
> >> Apple's pthread.h not including pthread_barrier support.      Looks
> >> like two lines in CMakeLists.txt under if(ENABLE_HOST_CPU_DEVICES)
> >> could be modified to turn off the pthreads device.   I also had
> >> success naively providing  implementations of the missing functions in
> >> file pthread_scheduler.c
> >>
> >>
> >>
> >> Warm regards,
> >>
> >> Noah
> >>
> >>
> >> _______________________________________________
> >> pocl-devel mailing list
> >> poc...@li...
> >> https://lists.sourceforge.net/lists/listinfo/pocl-devel
> >
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>
>
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