preparing to pass integrator, smearing, bc's as policy classes to hmc.
Propose to unify "integrator" and integrator algorithm in a base/derived
way to override step. Want to read through ForceGradient to ensure
that abstraction covers the force gradient case.
Example of multiple levels in the WilsonFermion hmc test.
Merge remote-tracking branch 'upstream/master'
Conflicts:
lib/qcd/hmc/HMC.h
lib/qcd/hmc/integrators/Integrator.h
lib/qcd/hmc/integrators/Integrator_algorithm.h
tests/Test_simd.cc
6000 matmuls CG unprec
2000 matmuls CG prec (4000 eo muls)
1050 matmuls PGCR on 16^3 x 32 x 8 m=.01
Substantial effort on timing and logging infrastructure
