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|
(* TEST
flags = "-dlambda -dno-unique-ids"
* expect *)
(* Check that the code produced by TMC reads reasonably well. *)
let[@tail_mod_cons] rec map f = function
| [] -> []
| x :: xs -> f x :: map f xs
;;
[%%expect{|
(letrec
(map
(function f param tail_mod_cons
(if param
(let (block = (makemutable 0 (apply f (field_imm 0 param)) 24029))
(seq (apply map_dps block 1 f (field_imm 1 param)) block))
0))
map_dps
(function dst offset[int] f param tail_mod_cons
(if param
(let
(block0_arg0 = (apply f (field_imm 0 param))
block = (makemutable 0 block0_arg0 24029))
(seq (setfield_ptr(heap-init)_computed dst offset block)
(apply map_dps block 1 f (field_imm 1 param) tailcall)))
(setfield_ptr(heap-init)_computed dst offset 0))))
(apply (field_mut 1 (global Toploop!)) "map" map))
val map : ('a -> 'b) -> 'a list -> 'b list = <fun>
|}]
(* check that TMC works for records as well *)
type 'a cell = { hd : 'a; tl : 'a rec_list }
and 'a rec_list = 'a cell option
[%%expect{|
0
type 'a cell = { hd : 'a; tl : 'a rec_list; }
and 'a rec_list = 'a cell option
|}]
let[@tail_mod_cons] rec rec_map f = function
| None -> None
| Some {hd; tl} -> Some { hd = f hd; tl = rec_map f tl }
;;
[%%expect{|
(letrec
(rec_map
(function f param tail_mod_cons
(if param
(let (*match* =a (field_imm 0 param))
(makeblock 0
(let
(block = (makemutable 0 (apply f (field_imm 0 *match*)) 24029))
(seq (apply rec_map_dps block 1 f (field_imm 1 *match*))
block))))
0))
rec_map_dps
(function dst offset[int] f param tail_mod_cons
(if param
(let
(*match* =a (field_imm 0 param)
block1_arg0 = (apply f (field_imm 0 *match*))
block = (makemutable 0 block1_arg0 24029))
(seq
(setfield_ptr(heap-init)_computed dst offset
(makeblock 0 block))
(apply rec_map_dps block 1 f (field_imm 1 *match*) tailcall)))
(setfield_ptr(heap-init)_computed dst offset 0))))
(apply (field_mut 1 (global Toploop!)) "rec_map" rec_map))
val rec_map : ('a -> 'b) -> 'a rec_list -> 'b rec_list = <fun>
|}]
(* check the case where several constructors are nested;
we want to avoid creating an intermediate destination
for each constructor. *)
let[@tail_mod_cons] rec trip = function
| [] -> []
| x :: xs -> (x, 0) :: (x, 1) :: (x, 2) :: trip xs
;;
[%%expect{|
(letrec
(trip
(function param tail_mod_cons
(if param
(let (x =a (field_imm 0 param))
(makeblock 0 (makeblock 0 (*,int) x 0)
(makeblock 0 (makeblock 0 (*,int) x 1)
(let (block = (makemutable 0 (makeblock 0 (*,int) x 2) 24029))
(seq (apply trip_dps block 1 (field_imm 1 param)) block)))))
0))
trip_dps
(function dst offset[int] param tail_mod_cons
(if param
(let
(x =a (field_imm 0 param)
block0_arg0 = (makeblock 0 (*,int) x 0)
block1_arg0 = (makeblock 0 (*,int) x 1)
block2_arg0 = (makeblock 0 (*,int) x 2)
block = (makemutable 0 block2_arg0 24029))
(seq
(setfield_ptr(heap-init)_computed dst offset
(makeblock 0 block0_arg0 (makeblock 0 block1_arg0 block)))
(apply trip_dps block 1 (field_imm 1 param) tailcall)))
(setfield_ptr(heap-init)_computed dst offset 0))))
(apply (field_mut 1 (global Toploop!)) "trip" trip))
val trip : 'a list -> ('a * int) list = <fun>
|}]
(* check nested-constructors whose arguments
are effectful: they need to be let-bound appropriately
(ideally, only in the DPS version) *)
let[@tail_mod_cons] rec effects f = function
| [] -> []
| (x, y) :: xs -> f x :: f y :: effects f xs
;;
[%%expect{|
(letrec
(effects
(function f param tail_mod_cons
(if param
(let (*match* =a (field_imm 0 param))
(makeblock 0 (apply f (field_imm 0 *match*))
(let
(block = (makemutable 0 (apply f (field_imm 1 *match*)) 24029))
(seq (apply effects_dps block 1 f (field_imm 1 param)) block))))
0))
effects_dps
(function dst offset[int] f param tail_mod_cons
(if param
(let
(*match* =a (field_imm 0 param)
block0_arg0 = (apply f (field_imm 0 *match*))
block1_arg0 = (apply f (field_imm 1 *match*))
block = (makemutable 0 block1_arg0 24029))
(seq
(setfield_ptr(heap-init)_computed dst offset
(makeblock 0 block0_arg0 block))
(apply effects_dps block 1 f (field_imm 1 param) tailcall)))
(setfield_ptr(heap-init)_computed dst offset 0))))
(apply (field_mut 1 (global Toploop!)) "effects" effects))
val effects : ('a -> 'b) -> ('a * 'a) list -> 'b list = <fun>
|}]
(* Check the case where several constructors
are nested across a duplicating context: the [f None ::]
part should not be duplicated in each branch. *)
let[@tail_mod_cons] rec map_stutter f xs =
f None :: (
match xs with
| [] -> []
| x :: xs -> f (Some x) :: map_stutter f xs
)
;;
[%%expect{|
(letrec
(map_stutter
(function f xs tail_mod_cons
(makeblock 0 (apply f 0)
(if xs
(let
(block =
(makemutable 0 (apply f (makeblock 0 (field_imm 0 xs)))
24029))
(seq (apply map_stutter_dps block 1 f (field_imm 1 xs)) block))
0)))
map_stutter_dps
(function dst offset[int] f xs tail_mod_cons
(let
(block0_arg0 = (apply f 0)
block = (makemutable 0 block0_arg0 24029))
(seq (setfield_ptr(heap-init)_computed dst offset block)
(if xs
(let
(block0_arg0 = (apply f (makeblock 0 (field_imm 0 xs)))
block = (makemutable 0 block0_arg0 24029))
(seq (setfield_ptr(heap-init)_computed block 1 block)
(apply map_stutter_dps block 1 f (field_imm 1 xs) tailcall)))
(setfield_ptr(heap-init)_computed block 1 0))))))
(apply (field_mut 1 (global Toploop!)) "map_stutter" map_stutter))
val map_stutter : ('a option -> 'b) -> 'a list -> 'b list = <fun>
|}]
(* Check the case where several constructors
are nested across a non-duplicating context;
the [f None :: .] part can be delayed below the let..in,
buts it expression argument must be let-bound
before the let..in is evaluated. *)
type 'a stream = { hd : 'a; tl : unit -> 'a stream }
let[@tail_mod_cons] rec smap_stutter f xs n =
if n = 0 then []
else f None :: (
let v = f (Some xs.hd) in
v :: smap_stutter f (xs.tl ()) (n - 1)
)
;;
[%%expect{|
0
type 'a stream = { hd : 'a; tl : unit -> 'a stream; }
(letrec
(smap_stutter
(function f xs n[int] tail_mod_cons
(if (== n 0) 0
(makeblock 0 (apply f 0)
(let
(v = (apply f (makeblock 0 (field_imm 0 xs)))
block = (makemutable 0 v 24029))
(seq
(apply smap_stutter_dps block 1 f (apply (field_imm 1 xs) 0)
(- n 1))
block)))))
smap_stutter_dps
(function dst offset[int] f xs n[int] tail_mod_cons
(if (== n 0) (setfield_ptr(heap-init)_computed dst offset 0)
(let
(block0_arg0 = (apply f 0)
v = (apply f (makeblock 0 (field_imm 0 xs)))
block = (makemutable 0 v 24029))
(seq
(setfield_ptr(heap-init)_computed dst offset
(makeblock 0 block0_arg0 block))
(apply smap_stutter_dps block 1 f (apply (field_imm 1 xs) 0)
(- n 1) tailcall))))))
(apply (field_mut 1 (global Toploop!)) "smap_stutter" smap_stutter))
val smap_stutter : ('a option -> 'b) -> 'a stream -> int -> 'b list = <fun>
|}]
|
