Desired Features for a PLONK Optimising Compiler

Compiler front end:

  • Standard things: Constant subexpression elimination etc.

Backend (gates and constraints):

  • Automatic custom gate synthesis for repeated basic blocks
  • Cost model for balancing proof size, prover exponentiations, maximum gate arity, gate depth.
  • Partitioning the circuit to combine multiple constraints into single domain eval (“row”).
    • Furthermore, partitions need not be disjoint. With large arity or otherwise, one is likely to be able to eval multiple constraints per domain on overlapping subsets in a single “row” or “window”. Examples: single-constraint matrix multiplication, single-constraint batch inversion.
  • For tables, choosing the right table sizes.

Thoughts:

  • Just like real compilers, best solutions will involve approximate optimisation with empirical benchmarks

Literature:

  • Compiler
  • VLSI