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<div><i><font style="color:#333333">Sent from my Verizon Wireless 4G LTE DROID</font></i></div>
<div><i><font style="color:#333333">On Aug 19, 2015 1:36 PM, César via Openmp-dev <</font></i><a href="mailto:openmp-dev@lists.llvm.org"><i><font style="color:#333333">openmp-dev@lists.llvm.org</font></i></a><i><font style="color:#333333">> wrote:</font></i></div>
<div><i><font style="color:#333333">></font></i></div>
<div><i><font style="color:#333333">> On Wed, Aug 19, 2015 at 3:07 PM, Jack Howarth <</font></i><a href="mailto:howarth.mailing.lists@gmail.com"><i><font style="color:#333333">howarth.mailing.lists@gmail.com</font></i></a><i><font style="color:#333333">> wrote:</font></i></div>
<div><i><font style="color:#333333">>></font></i></div>
<div><i><font style="color:#333333">>> On Tue, Aug 18, 2015 at 2:14 PM, César via Openmp-dev</font></i></div>
<div><i><font style="color:#333333">>> <</font></i><a href="mailto:openmp-dev@lists.llvm.org"><i><font style="color:#333333">openmp-dev@lists.llvm.org</font></i></a><i><font style="color:#333333">> wrote:</font></i></div>
<div><i><font style="color:#333333">>> > Hello,</font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> > I don't know if this is the correct list to talk about this - I did not find</font></i></div>
<div><i><font style="color:#333333">>> > a better place..</font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> > I am doing performance experiments with a few OpenMP implementations (IOMP,</font></i></div>
<div><i><font style="color:#333333">>> > GOMP and our private impl.) and I am seeing a severe slowdown when I use</font></i></div>
<div><i><font style="color:#333333">>> > IOMP (GOMP and others are performing well).</font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> > The benchmarks I am using are these ones:</font></i></div>
<div><i><font style="color:#333333">>> > </font></i><a href="http://kastors.gforge.inria.fr/#!index.md"><i><font style="color:#333333">http://kastors.gforge.inria.fr/#!index.md</font></i></a></div>
<div><i><font style="color:#333333">>></font></i></div>
<div><i><font style="color:#333333">>> That web page claims the benchmarks use parts of the OpenMP 4.0 specification.</font></i></div>
<div><i><font style="color:#333333">>></font></i></div>
<div><i><font style="color:#333333">>> "The KaStORS benchmark suite has been designed to evaluate the implementation of</font></i></div>
<div><i><font style="color:#333333">>> the OpenMP dependent task paradigm, introduced as part of the OpenMP 4.0</font></i></div>
<div><i><font style="color:#333333">>> specification."</font></i></div>
<div><i><font style="color:#333333">>></font></i></div>
<div><i><font style="color:#333333">>> Currently openmp is only complete for the OpenMP 3.2 specification</font></i></div>
<div><i><font style="color:#333333">>></font></i></div>
<div><i><font style="color:#333333">></font></i></div>
<div><i><font style="color:#333333">> I am able to compile a few benchmarks that use task dependence annotations (from OMP 4.0) but for those that specify the range of the memory dependence I get syntax error. So, should I assume that this part is not implemented,
right? Is there a list for the OMP 4.0 items that are currently supported?</font></i></div>
<div><i><font style="color:#333333">></font></i></div>
<div><i><font style="color:#333333">> BTW, the Clang version from Github was able to parse these annotations, was it dropped from the current newer version?</font></i></div>
<div><i><font style="color:#333333">></font></i></div>
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<div><i><font style="color:#333333">It is not there yet. You'll need to use the code from the github clang_trunk (and llvm_trunk, etc.) repositories to get both recent Clang/LLVM and all of the OpenMP features.</font></i></div>
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<div><i><font style="color:#333333">-Hal</font></i></div>
<div><i><font style="color:#333333"><br>
</font></i></div>
<div><i><font style="color:#333333">> </font></i></div>
<div><i><font style="color:#333333">>></font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> > Really, the slowdown is huge. For one of the programs (plasma/dpotrf_taskdep</font></i></div>
<div><i><font style="color:#333333">>> > -n 8192 -b 64 -i 1 -c) the serial version executes in ~28s and the parallel</font></i></div>
<div><i><font style="color:#333333">>> > one executes in ~110s. I did some profiling and found that most of the time</font></i></div>
<div><i><font style="color:#333333">>> > is being spent on synchronization barriers and dependence tracking (see</font></i></div>
<div><i><font style="color:#333333">>> > attached image). Before digging deeper I would like to hear back from you if</font></i></div>
<div><i><font style="color:#333333">>> > I am doing something wrong here:</font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> > - I tested with the last version of the repository:</font></i></div>
<div><i><font style="color:#333333">>> > </font></i><a href="http://llvm.org/svn/llvm-project/openmp/trunk"><i><font style="color:#333333">http://llvm.org/svn/llvm-project/openmp/trunk</font></i></a></div>
<div><i><font style="color:#333333">>> > - I am using Ubuntu 14.10.</font></i></div>
<div><i><font style="color:#333333">>> > - I have tested on more than one machine, the results above are from a Intel</font></i></div>
<div><i><font style="color:#333333">>> > i7-3770</font></i></div>
<div><i><font style="color:#333333">>> > - The runtime itself is compiled using: make compiler=gcc os_omp=linux</font></i></div>
<div><i><font style="color:#333333">>> > arch=32e</font></i></div>
<div><i><font style="color:#333333">>> > - The version of GCC that I am using is: 4.9.1</font></i></div>
<div><i><font style="color:#333333">>> > - The version of Clang that I am using to compile the benchmarks: 3.5.0</font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> > César.</font></i></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">>> > _______________________________________________</font></i></div>
<div><i><font style="color:#333333">>> > Openmp-dev mailing list</font></i></div>
<div><i><font style="color:#333333">>> > </font></i><a href="mailto:Openmp-dev@lists.llvm.org"><i><font style="color:#333333">Openmp-dev@lists.llvm.org</font></i></a></div>
<div><i><font style="color:#333333">>> > </font></i><a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/openmp-dev"><i><font style="color:#333333">http://lists.llvm.org/cgi-bin/mailman/listinfo/openmp-dev</font></i></a></div>
<div><i><font style="color:#333333">>> ></font></i></div>
<div><i><font style="color:#333333">></font></i></div>
<div><i><font style="color:#333333">></font></i></div>
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<div><font style="color:#333333"><i>Sent from my Verizon Wireless 4G LTE DROID</i></font></div>
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