Files
lci/lib/miniImp/definedVariables.ml
2024-12-16 05:15:33 +01:00

257 lines
8.6 KiB
OCaml

open Analysis
module Variable = struct
type t = string
let pp (ppf: out_channel) (v: t) : unit =
Printf.fprintf ppf "%s" v
let pplist (ppf: out_channel) (vv: t list) : unit =
List.iter (Printf.fprintf ppf "%s, ") vv
let compare a b =
String.compare a b
end
module RISCCfg = CfgRISC.RISCCfg
module DVCfg = Dataflow.Make (CfgRISC.RISCSimpleStatements) (Variable)
module DVCeltSet = Set.Make(Variable)
let variables_used (instr : DVCfg.elt) : DVCfg.internal list =
let helper (acc: DVCeltSet.t) (instr: DVCfg.elt) =
match instr with
| Nop
| LoadI (_, _) ->
acc
| BRegOp (_, r1, r2, _) ->
DVCeltSet.add r1.index acc |>
DVCeltSet.add r2.index
| BImmOp (_, r1, _, _)
| URegOp (_, r1, _)
| Load (r1, _)
| Store (r1, _) ->
DVCeltSet.add r1.index acc
in
helper DVCeltSet.empty instr |> DVCeltSet.to_list
let variables_used_all (instructions : DVCfg.elt list) : DVCfg.internal list =
List.fold_left (fun (acc: DVCeltSet.t) (instr: DVCfg.elt) ->
DVCeltSet.union acc (variables_used instr |> DVCeltSet.of_list)
) DVCeltSet.empty instructions |> DVCeltSet.to_list
let variables_defined (instructions : DVCfg.elt) : DVCfg.internal list =
let helper (acc: DVCeltSet.t) (instr: DVCfg.elt) =
match instr with
| Nop -> acc
| BRegOp (_, _, _, r3)
| BImmOp (_, _, _, r3)
| URegOp (_, _, r3)
| Load (_, r3)
| LoadI (_, r3)
| Store (_, r3) ->
DVCeltSet.add r3.index acc
in
helper DVCeltSet.empty instructions |> DVCeltSet.to_list
let variables_defined_all (instructions : DVCfg.elt list) : DVCfg.internal list =
List.fold_left (fun (acc: DVCeltSet.t) (instr: DVCfg.elt) ->
DVCeltSet.union acc (variables_defined instr |> DVCeltSet.of_list)
) DVCeltSet.empty instructions |> DVCeltSet.to_list
let _variables_defined_nth (instructions : DVCfg.elt list) (i: int) : DVCfg.internal list =
variables_defined (List.nth instructions i)
let _variables_defined_last (instructions : DVCfg.elt list) : DVCfg.internal list =
variables_defined (List.nth instructions ((List.length instructions) - 1))
(* init function, assign the epmpty set to everything *)
let init : (DVCfg.elt list -> DVCfg.internalnode) =
(fun l -> {internalin = [];
internalout = [];
internalbetween = (List.init (List.length l) (fun _ -> ([], [])))})
(* piece of code that computes vout for the whole block, not used,
use lub below *)
let _dumb_lub (t: DVCfg.t) (node: Cfg.Node.t) : DVCfg.internalnode =
let previnternalvar = Cfg.NodeMap.find node t.internalvar in
let code = Cfg.NodeMap.find node t.t.content in
{ previnternalvar with
internalout =
Utility.unique_union (variables_defined_all code) (previnternalvar.internalin)
}
(* We consider only the propagation in the middle elements during the lub.
This incurs in a performance penality, but it is simpler to implement.
Each node is connected to one previus node.
*)
let lub (t: DVCfg.t) (node: Cfg.Node.t) : DVCfg.internalnode =
let previnternalvar = Cfg.NodeMap.find node t.internalvar in
let code = match Cfg.NodeMap.find_opt node t.t.content with
None -> []
| Some c -> c
in
{ previnternalvar with
internalbetween =
List.mapi (* we don't NEED the index but i = 0 is easier to write than
to check if vinout is None *)
(fun i (ithcode, vinout, ithcodeprev) ->
if i = 0 then
let dvin = previnternalvar.internalin in
(dvin, Utility.unique_union dvin (variables_defined ithcode))
else (
let ithcodeprev = match ithcodeprev with
None -> ([], [])
| Some x -> x
in
match vinout with
None ->
([], variables_defined ithcode)
| Some prevdvbtw ->
(snd prevdvbtw,
Utility.unique_union
(variables_defined ithcode)
(ithcodeprev |> fst)
))
)
(* ugly code that zips the three lists that we need to compute each vin
and vout for the middle of the code *)
(Utility.combine_thrice
code
(Utility.pad_opt
(Utility.prev previnternalvar.internalbetween None) None (List.length code))
(Utility.pad previnternalvar.internalbetween None (List.length code))
);
internalout =
match previnternalvar.internalbetween with
[] -> previnternalvar.internalin
| _ -> (snd (Utility.last_list previnternalvar.internalbetween))
}
let lucf (t: DVCfg.t) (node: Cfg.Node.t) : DVCfg.internalnode =
let previnternalvar = Cfg.NodeMap.find node t.internalvar in
if Option.equal (=) (Some node) t.t.initial then
{ previnternalvar with
internalin =
match t.t.inputOutputVar with
Some (i, _) -> [i]
| None -> []
}
else
let prevnodes = Cfg.NodeMap.find node t.t.reverseEdges in
{ previnternalvar with
internalin =
match prevnodes with
[] -> []
| [prevnode] -> (Cfg.NodeMap.find prevnode t.internalvar).internalout
| [prevnode1; prevnode2] ->
Utility.unique_intersection
(Cfg.NodeMap.find prevnode1 t.internalvar).internalout
(Cfg.NodeMap.find prevnode2 t.internalvar).internalout
| _ ->
List.fold_left (* intersection of all previous nodes' dvout *)
(fun acc prevnode ->
Utility.unique_intersection acc (Cfg.NodeMap.find prevnode t.internalvar).internalout)
[]
prevnodes
}
let update (t: DVCfg.t) (node: Cfg.Node.t) : DVCfg.internalnode =
let newt = {t with internalvar = (Cfg.NodeMap.add node (lucf t node) t.internalvar)} in
lub newt node
let compute_defined_variables (cfg: RISCCfg.t) : DVCfg.t =
DVCfg.from_cfg cfg
|> DVCfg.fixed_point ~init:init ~update:update
let check_defined_variables (dvcfg: DVCfg.t) : bool =
let helper node (dvcfg: DVCfg.t) =
let code = match Cfg.NodeMap.find_opt node dvcfg.t.content with
None -> []
| Some c -> c
in
let internalvar = Cfg.NodeMap.find node dvcfg.internalvar in
let vua = variables_used_all code in
let outvar = (* is true if we are in the last node and the out variable is
not in vout, so its true if the out variable is not
defined *)
match (Option.equal (=) (Some node) dvcfg.t.terminal,
dvcfg.t.inputOutputVar,
internalvar.internalout) with
| (true, Some (_, outvar), vout) ->
not (List.mem outvar vout)
| (_, _, _) ->
false
in
if Utility.inclusion vua (internalvar.internalin) then
not outvar
else
(* the variable might be defined inside the block, so check all vin and
return true only if all variables are properly defined *)
let vuabetween = List.map variables_used code in
let check = List.fold_left
(fun acc (codevars, (vin, _vout)) ->
acc && (Utility.inclusion codevars vin))
true
(List.combine vuabetween internalvar.internalbetween)
in
check && (not outvar)
in
Cfg.NodeSet.fold (fun node acc -> acc && (helper node dvcfg)) dvcfg.t.nodes true
let undefined_variables (dvcfg: DVCfg.t) : Variable.t list =
let helper (node: Cfg.Node.t) (dvcfg: DVCfg.t) =
let code = match Cfg.NodeMap.find_opt node dvcfg.t.content with
None -> []
| Some c -> c
in
let internalvar = Cfg.NodeMap.find node dvcfg.internalvar in
let vua = variables_used_all code in
let outvar =
match (Option.equal (=) (Some node) dvcfg.t.terminal,
dvcfg.t.inputOutputVar,
internalvar.internalout) with
| (true, Some (_, outvar), vout) ->
if List.mem outvar vout
then None
else Some outvar
| (_, _, _) ->
None
in
if Utility.inclusion vua (internalvar.internalin) then
match outvar with None -> [] | Some outvar -> [outvar]
else
(* the variable might be defined inside the block, so check all vin and
return true only if all variables are properly defined *)
let vuabetween = List.map variables_used code in
let undef_vars = List.fold_left
(fun acc (codevars, (vin, _vout)) ->
(Utility.subtraction codevars vin) @ acc)
[]
(List.combine vuabetween internalvar.internalbetween)
in
match outvar with None -> undef_vars | Some outvar -> outvar :: undef_vars
in
Cfg.NodeSet.fold (fun node acc -> acc @ (helper node dvcfg)) dvcfg.t.nodes []
let compute_cfg (dvcfg: DVCfg.t) : RISCCfg.t =
DVCfg.to_cfg dvcfg