2020-07-23

Actually, when running analyseStm and analyseBody, I don't think I need to actually update any statements? So I don't need to return an updated statement or body.

In if and loop expressions, I probably also have to handle parameters in the conditional and loop initialization/form, respectively. The names in there should interfere with the names in the bodies/body and with the names in the pattern.

analyseBody :: LastUseMap -> Stms -> (InUse, LastUsed, MemGraph)
analyseBody lumap stms =
  let inuse = ∅
  let graph = ∅
  let lus = ∅
  for each stm in stms:
    let (inuse, lus', graph) = analyseStm lumap inuse graph stm
    let lus = lus ∪ lus'
  return (inuse, lus, graph)

analyseStm :: LastUseMap -> InUse -> MemGraph -> Stm -> (InUse, LastUsed, MemGraph)
analyseStm lu_map inuse0 graph0 (let p = exp) =
  let mems = memory blocks referenced in p
  let inuse = inuse0 ∪ mems
  let graph = graph0 ∪ (inuse ↔ inuse)
  let lus0' = lookup p in lu_map
  let lus0 = memory blocks referenced in lus

  if exp is a loop with body b then
    let (inuse', lus, graph') = analyseBody lu_map b
    let lus' = lus ∪ lus0
    let graph'' = graph ∪ graph' ∪ (inuse ↔ (inuse' ∪ lus))
    let inuse'' = inuse ∖ lus ∪ inuse'
    in (inuse'', lus', graph'')
  else if exp is a if with bodies b1, b2 then
    let (inuse1, lus1, g1) = analyseBody lu_map b1
    let (inuse2, lus2, g2) = analyseBody lu_map b2
    let lus = lus0 ∪ lus1 ∪ lus2
    let inuse' = (inuse ∪ inuse1 ∪ inuse2) ∖ lus
    let g = graph ∪ g1 ∪ g2
              ∪ ((inuse1 ∪ lus1) ↔ (inuse ∖ (lus2 ∖ lus1)))
              ∪ ((inuse2 ∪ lus2) ↔ (inuse ∖ (lus1 ∖ lus2)))
    in (inuse', lus, g)
  else if exp is a kernel call with a body b then
    same as loop†
  else
    let inuse' = inuse ∖ lus0
    in (inuse', lus0, graph)

Some more work got done. At the end, I tried to get a proper inference-graph for my if.fut test. For some reason mem_37 never runs out of scope, so something is wrong. I also need to actually make my analysis only work on kernels.