notes.txt

TODOS

* passes to fix other cases: uid groupby, tout==inf, packet cloning, should not
  need to use switchId inside the p4 code

domino related
* can we reduce outcast.sql compiler output size? 15 stages may be high...

additional compiler passes
* pass: detect vector-valued state with linear updates
* pass: handling groupby code generation correctly with `uid` in aggregation
* pass: combine with located expr tree to only install on specific switches
* pass: rules needed to generate outputs for query. By default, assume each
  stage is some intermediate stage; generate output code only for toplevel.
* pass: include evicted key-value outputs on the cloned packet
* handle tout==infinity in filter code generation

issues to think about
* guarantees of fixed point algorithms for linear-in-state + bounded packet hist
  - casting as lattice theory/abstract interpretation
* semantics for multi-stage groupby queries
* emit() versus functional design

hardware-oriented passes
* making kv store an extern + configure extern
* configure domino atoms from aggregation functions
* configure the tofino chip(?)

simplifying code
* simplify ternary threeopstmts. e.g., z = true ? x : y ==> z = x
* remove define-before-use checking class and redundant code
* change code generated for map to 'functional' semantics?
* make predicates "smart", e.g., AugPred(true).and(X) == X
* current map code is dead code if operand is invalid
* cleanup code: add @Override annotation to new antlr visitor passes!
* simple way to check whether a switch is an egress switch?
* language identifiers for constants, like TCP protocol number

possible error handling for aggregate functions
* warn if no code path changes the state variables
* print code line numbers in errors. e.g., see define before use error msgs
* better formatting for error messages

template
* setting default acc value for aggregation function in language & template?