Performance Portability Strategies for Grid C++ Expression Templates

One of the key requirements for the Lattice QCD Application Development as part of the US Exascale Computing Project is performance portability across multiple architectures. Using the Grid C++ expression template as a starting point, we report on the progress made with regards to the Grid GPU offloading strategies. We present both the successes and issues encountered in using CUDA, OpenACC and Just-In-Time compilation. Experimentation and performance on GPUs with a SU(3)$\times$SU(3) streaming test will be reported. We will also report on the challenges of using current OpenMP 4.x for GPU offloading in the same code.Comment: 8 pages, 4 figures. Talk presented at the 35th International Symposium on Lattice Field Theory, 18-24 June 2017, Granada, Spai

Lattice Determination of the Hadronic Contribution to the Muon g−2g-2 using Dynamical Domain Wall Fermions

We present a calculation of the leading order hadronic contribution to the anomalous magnetic moment of the muon for a dynamical simulation of 2+1 flavour QCD using domain wall fermions. The electromagnetic 2-point function is evaluated on the RBC-UKQCD lattice gauge configurations and this is fitted to a continuous form motivated by models of vector dominance. We determine a robust and reliable technique for performing this fit, allowing us to extract the most accurate results possible from our ensembles. This combined with data at very light quark masses produces the result a_\mu^{(2)had}=641(33)(32) x 10^{-10} at the physical point, where the first uncertainty is statistical, and the second is an estimate of systematics, which is in agreement with previous results. We outline various methods by which this calculation can and will be improved in order to compete with the accuracy of alternative techniques of deducing this quantity from experimental scattering data.Comment: 18 pages, 1

The globalisation of breast cancer

Boyle, Peter Howell, Antony eng England 2011/01/05 06:00 Breast Cancer Res. 2010 Dec 20;12 Suppl 4:S7. doi: 10.1186/bcr2736.International audienceno abstrac