Feature Request

Planned Features

• Edge/Faces values for FVM
• Loop transformations blocking, tilling for Phase-Field values
• Loop reduction for LBM evaluation/debugging/output (i.e. max, sum ...)
• LLVM?, PACXXX??
• LBM list kernel+++
• Vectorisierung
• LROP (Sparse Phases)
• Boundaries
• CSE???
• Communication code for LBM
• Layouts for LBM

Planned Architecture

• Stage 1: ordered list of sympy equations,

  • this stage should remain unchanged (interface stability)
  • contains Field.Access objects
  • contains sp.Piecewise functions to represent ifs
  • in the future it might also contain reduction markers to do reductions in the same step as the computation. for example: a lattice boltzmann kernel somewhere computes velocity: a reduction can be defined to compute the maximal velocity over all cells
  • may also contain TypedSymbols i.e. sympy symbols that are annotated with their type

• Stage 2:

  • Type untyped Symbols

• Stage 3: AST with as few transformation done as possible

  • loops are written around equations - loop over all cells - indexed kernels: (x,y,z) is loaded from an index fields (struct support!)
  • KernelFunction node (which should be fully functional already, knows parameters etc) is the outermost node
  • field accesses are not yet resolved, however the loop counters are introduced to make relative to absolute indices f[1,-1] gets f[ctr0 + 1, ctr1 - 1]

• Stage 4: Field accesses are resolved to pointer arithmetic

  • can be splitted into resolveArrayAccesses and resolveStructAccesses
  • no information should be lost in this stage, i.e. the Indexed nodes should still know their field

• Stage 5: Typing of all expressions with a dict and insertion of cast nodes

Transformations

• move constants before loop (after stage 5)
• cache blocking of loops (after stage 5)
• loop peeling to make main loop pointer access aligned (after stage 5)
• loop splitting for LBM split kernels (currently done after Stage 3, can this also be moved after stage 5?)