| 446 |
if List.all (C.dead o C.get) lvs |
if List.all (C.dead o C.get) lvs |
| 447 |
then loop nm body cont |
then loop nm body cont |
| 448 |
else cbody() |
else cbody() |
|
| (F.BRANCH _ | F.SWITCH _) => |
|
|
(* this is a hack originally meant to cleanup the BRANCH |
|
|
* mess introduced in flintnm (where each branch returns |
|
|
* just true or false which is generally only used as |
|
|
* input to a SWITCH). |
|
|
* The present code does more than clean up this case. |
|
|
* It has one serious shortcoming: it ends up making |
|
|
* three fcontract passes through the same code (plus |
|
|
* one cheap traversal). *) |
|
|
let fun cassoc (lv,F.SWITCH(F.VAR v,ac,arms,NONE),wrap) = |
|
|
if lv <> v orelse C.usenb(C.get lv) > 1 |
|
|
then cbody() else |
|
|
let val (narms,fdecs) = |
|
|
ListPair.unzip (map extract arms) |
|
|
fun addswitch [v] = |
|
|
C.copylexp |
|
|
M.empty |
|
|
(F.SWITCH(v,ac,narms,NONE)) |
|
|
| addswitch _ = bug "prob in addswitch" |
|
|
(* replace each leaf `ret' with a copy |
|
|
* of the switch *) |
|
|
val nle = append [lv] addswitch nle |
|
|
(* decorate with the functions extracted |
|
|
* from the switch arms *) |
|
|
val nle = |
|
|
foldl (fn (f,le) => F.FIX([f],le)) |
|
|
(wrap nle) fdecs |
|
|
(* Ugly hack: force one more traversal *) |
|
|
(* val nle = loop nm nle #2 *) |
|
|
in click_branch(); |
|
|
loop nm nle cont |
|
|
end |
|
|
| cassoc _ = cbody() |
|
|
in case (lvs,body) |
|
|
of ([lv],le as F.SWITCH _) => |
|
|
cassoc(lv, le, fn x => x) |
|
|
| ([lv],F.LET(lvs,le as F.SWITCH _,rest)) => |
|
|
cassoc(lv, le, fn le => F.LET(lvs,le,rest)) |
|
|
| _ => cbody() |
|
|
end |
|
| 449 |
| _ => cbody() |
| _ => cbody() |
| 450 |
end) |
end) |
| 451 |
|
|
Parent Directory
| 
Revision Log
| 
Patch
