search for: parallelization

qemu-io 2.12 will be changing its default alignment to unknown servers so that it does read-modify-write for anything less than 512 bytes. If we implement NBD_OPT_GO, then we can keep qemu-io using 1-byte alignment; but until then, this breaks our parallel tests when using 1-byte alignment because they end up with more delays than expected (thanks to the read-modify-write). Revamp the tests to

...e full OpenMP specification, and I'd like to know what the community thinks about this. As a general note: My intent here is to make the metadata safe in the traditional sense: it can be removed by optimization passes that don't understand it, and while this might result in the loss of the parallelization, the removal will not be otherwise unsafe. I believe that many existing passes will require minor modification in order to preserve the metadata as appropriate, but I think these changes are relatively small. In addition, the authors of passes that preserve parallelization by dealing with paralleli...

...ext goal] * A cost analysis for parallel tasks that can be queried by optimizations. The cost model needs to take the hardware, the runtime library and the parallel tasks into account. * Vectorizer enhancements to enable the vectorization of parallel * loops and tasks. * Parallelization centric optimizations: a) Parallel tasks can be balanced, merged or split as well as created from and lowered to sequential code. b) Barriers can be eliminated. c) Parallel loops can be statically scheduled or created from parallel recursive calls [13] * Ana...

If nbdkit has a bug (such as the nbd-standalone bug fixed in the previous commit), qemu-io ends up waiting forever rather than realizing that if the server disappears unexpectedly then qemu-io should quit. So add timeouts so the testsuite will flag the problem instead of hang (tested by reordering this commit before the previous). It's trickier than I expected: from the command line,

...ferences specifying > special-handling child regions (parallel loops and serialized/critical > regions) > > If the special-handling region metadata is no longer referenced by code > within the parallel region, then the region has become invalid, and > will be removed (meaning all parallelization metadata will be removed) > by the ParallelizationCleanup. The same is true for all other > cross-referenced metadata below. > > Note that parallel regions can be nested. > > As a quick example, something like: > int main() { > int a; > #pragma omp parallel firstpriva...

...that can be queried by > > optimizations. The cost model needs to take the hardware, the > > runtime library and the parallel tasks into account. > > * Vectorizer enhancements to enable the vectorization of parallel > > * loops and tasks. > > * Parallelization centric optimizations: > > a) Parallel tasks can be balanced, merged or split as well as created > > from and lowered to sequential code. > > b) Barriers can be eliminated. > > c) Parallel loops can be statically scheduled or created from > &gt...

I'm part of a research group at MIT looking to create an extension of LLVM that inherently allows one to nicely code a parallel loop. Most parallel frameworks tend to take the body of a parallel loop and stick it inside of a function for the parallel runtime to call when appropriate. However, this makes optimizations significantly more difficult as most compiler optimizations tend to be

...l needs to take the hardware, the >>>>>> runtime library and the parallel tasks into account. >>>>>> * Vectorizer enhancements to enable the vectorization of parallel >>>>>> * loops and tasks. >>>>>> * Parallelization centric optimizations: >>>>>> a) Parallel tasks can be balanced, merged or split as well as created >>>>>> from and lowered to sequential code. >>>>>> b) Barriers can be eliminated. >>>>>> c)...

...by >>> optimizations. The cost model needs to take the hardware, the >>> runtime library and the parallel tasks into account. >>> * Vectorizer enhancements to enable the vectorization of parallel >>> * loops and tasks. >>> * Parallelization centric optimizations: >>> a) Parallel tasks can be balanced, merged or split as well as created >>> from and lowered to sequential code. >>> b) Barriers can be eliminated. >>> c) Parallel loops can be statically scheduled or create...

...optimizations. The cost model needs to take the hardware, the > >>> runtime library and the parallel tasks into account. > >>> * Vectorizer enhancements to enable the vectorization of parallel > >>> * loops and tasks. > >>> * Parallelization centric optimizations: > >>> a) Parallel tasks can be balanced, merged or split as well as created > >>> from and lowered to sequential code. > >>> b) Barriers can be eliminated. > >>> c) Parallel loops can be statically...

...including target-specific lowering. What follows outlines > a set of metadata and intrinsics which should allow support for the > full OpenMP specification, and I'd like to know what the community > thinks about this. Something like this would be useful also for OpenCL C work group parallelization. At the moment in pocl we do this in a hackish way with an "overkill" OpenCL C-specific metadata that is fed to a modified bb-vectorizer of yours for autovectorization and a custom alias analyzer for AA benefits. I'd like to remind that multithreading is just one option on how to map...

On Feb 7, 2013, at 10:55 AM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: > Hi Nadav, > > On 02/07/2013 07:46 PM, Nadav Rotem wrote: >> Pekka suggested that we add two kind of metadata: llvm.loop.parallel >> (attached to each loop latch) and llvm.mem.parallel (attached to each memory >> instruction!). I think that the motivation for the first

Dear all, Here's an updated version of the parallel loop metadata patch. It includes documentation for the new metadata types with a semantics description. -- Pekka -------------- next part -------------- A non-text attachment was scrubbed... Name: parallel-loop-metadata.patch Type: text/x-patch Size: 12972 bytes Desc: not available URL:

...e >>>>>>>> runtime library and the parallel tasks into account. >>>>>>>> * Vectorizer enhancements to enable the vectorization of parallel >>>>>>>> * loops and tasks. >>>>>>>> * Parallelization centric optimizations: >>>>>>>> a) Parallel tasks can be balanced, merged or split as well as created >>>>>>>> from and lowered to sequential code. >>>>>>>> b) Barriers can be eliminated. >>>...

...he cost model needs to take the hardware, the > > >>> runtime library and the parallel tasks into account. > > >>> * Vectorizer enhancements to enable the vectorization of parallel > > >>> * loops and tasks. > > >>> * Parallelization centric optimizations: > > >>> a) Parallel tasks can be balanced, merged or split as well as created > > >>> from and lowered to sequential code. > > >>> b) Barriers can be eliminated. > > >>> c) Parallel loo...

...l needs to take the hardware, the >>>>>> runtime library and the parallel tasks into account. >>>>>> * Vectorizer enhancements to enable the vectorization of parallel >>>>>> * loops and tasks. >>>>>> * Parallelization centric optimizations: >>>>>> a) Parallel tasks can be balanced, merged or split as well as created >>>>>> from and lowered to sequential code. >>>>>> b) Barriers can be eliminated. >>>>>> c)...

On Wed, Jan 30, 2013 at 12:35 PM, Pekka Jääskeläinen <pekka.jaaskelainen at tut.fi> wrote: > Thank you all for comments, > > > On 01/30/2013 11:22 AM, David Tweed wrote: >> >> In a personal capacity I'm quite interested in the issues of producing >> from a >> high-level language some LLVM IR which is labelled with vectorization info >> (including

...gt;>>> optimizations. The cost model needs to take the hardware, the >>>> runtime library and the parallel tasks into account. >>>> * Vectorizer enhancements to enable the vectorization of parallel >>>> * loops and tasks. >>>> * Parallelization centric optimizations: >>>> a) Parallel tasks can be balanced, merged or split as well as created >>>> from and lowered to sequential code. >>>> b) Barriers can be eliminated. >>>> c) Parallel loops can be statically scheduled or c...

This is for consistency with qemu-img, socat, ss, etc where we test for these binaries at run time. --- configure.ac | 4 ---- tests/Makefile.am | 8 +++----- tests/test-parallel-file.sh | 20 +++++++++++++------- tests/test-parallel-nbd.sh | 20 +++++++++++++------- 4 files changed, 29 insertions(+), 23 deletions(-) diff --git a/configure.ac b/configure.ac index

...llvm.loop.ignore_assumed_deps to support that. Anyways, my desire is to start from something as it's easier to build on existing foundations. > To clarify history, the reason that the metadata-based OpenMP schemes died > was not due to the "propeller" arguments (which said that parallelization > semantics are just not a good fit for LLVM), but rather due to fundamental > correctness issues specific to OpenMP. Specifically, there are cases where > it would not be legal to drop metadata that produced parallel regions, and > a fundamental design principle of metadata is that dro...