The BAGEL assembler generation library

This paper presents two coupled software packages which receive widespread use in the field of numerical simulations of Quantum Chromo-Dynamics. These consist of the BAGEL library and the BAGEL fermion sparse-matrix library, BFM.The Bagel library can generate assembly code for a number of architectures and is configurable – supporting several precision and memory pattern options to allow architecture specific optimisation. It provides high performance on the QCDOC, BlueGene/L and BlueGene/P parallel computer architectures that are popular in the field of lattice QCD. The code includes a complete conjugate gradient implementation for the Wilson and domain wall fermion actions, making it easy to use for third party codes including the Jefferson Laboratory's CHROMA, UKQCD's UKhadron, and the Riken–Brookhaven–Columbia Collaboration's CPS packages.Program summaryProgram title: BagelCatalogue identifier: AEFE_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFE_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU Public License V2No. of lines in distributed program, including test data, etc.: 109 576No. of bytes in distributed program, including test data, etc.: 892 841Distribution format: tar.gzProgramming language: C++, assemblerComputer: Massively parallel message passing. BlueGene/QCDOC/others.Operating system: POSIX, Linux and compatible.Has the code been vectorised or parallelized?: Yes. 16 384 processors used.Classification: 11.5External routines: QMP, QDP++Nature of problem: Quantum Chromo-Dynamics sparse matrix inversion for Wilson and domain wall fermion formulations.Solution method: Optimised Krylov linear solver.Unusual features: Domain specific compiler generates optimised assembly code.Running time: 1 h per matrix inversion; multi-year simulations.