[sledge] Move locals from blocks to functions

Summary:
The entry block contains all locals of the entire function, as
required by the backend. This makes the manipulation of the locals of
each block redundant.

This diff moves the locals from the entry block to the function
itself, removes the Locals frames of the Control.Stack, and adds a
locals field to Return frames.

This is part cleanup and part preparation for removing the
Control.Stack.

Reviewed By: ngorogiannis

Differential Revision: D15963503

fbshipit-source-id: 523ebc260
master
Josh Berdine 6 years ago committed by Facebook Github Bot
parent 9d9df458b6
commit b14580d88b

@ -16,7 +16,6 @@ module Stack : sig
type as_inlined_location = t [@@deriving compare, sexp_of] type as_inlined_location = t [@@deriving compare, sexp_of]
val empty : t val empty : t
val push_jump : Var.Set.t -> t -> t
val push_call : val push_call :
Llair.block Llair.block
@ -28,22 +27,21 @@ module Stack : sig
-> t -> t
-> t option -> t option
val pop_return : val pop_return : t -> (Domain.from_call * Llair.jump * t) option
t -> (Var.Set.t * Domain.from_call * Llair.jump * t) option
val pop_throw : val pop_throw :
t t
-> init:'a -> init:'a
-> unwind:(Var.t list -> Var.Set.t -> Domain.from_call -> 'a -> 'a) -> unwind:(Var.t list -> Var.Set.t -> Domain.from_call -> 'a -> 'a)
-> (Var.Set.t * Domain.from_call * Llair.jump * t * 'a) option -> (Domain.from_call * Llair.jump * t * 'a) option
end = struct end = struct
type t = type t =
| Locals of Var.Set.t * t
| Return of | Return of
{ retreating: bool { retreating: bool
(** return from a call not known to be nonrecursive *) (** return from a call not known to be nonrecursive *)
; dst: Llair.Jump.t ; dst: Llair.Jump.t
; params: Var.t list ; params: Var.t list
; locals: Var.Set.t
; from_call: Domain.from_call ; from_call: Domain.from_call
; stk: t } ; stk: t }
| Throw of Llair.Jump.t * t | Throw of Llair.Jump.t * t
@ -54,15 +52,13 @@ end = struct
(* Treat a stack as a code location in a hypothetical expansion of the (* Treat a stack as a code location in a hypothetical expansion of the
program where all non-recursive functions have been completely inlined. program where all non-recursive functions have been completely inlined.
In particular, this means to compare stacks as if all Locals frames or In particular, this means to compare stacks as if all Return frames for
Return frames for recursive calls had been removed. Additionally, the recursive calls had been removed. Additionally, the from_call info in
from_call info in Return frames is ignored. *) Return frames is ignored. *)
let rec compare_as_inlined_location x y = let rec compare_as_inlined_location x y =
if x == y then 0 if x == y then 0
else else
match (x, y) with match (x, y) with
| Locals (_, x), y
|x, Locals (_, y)
| Return {retreating= true; stk= x}, y | Return {retreating= true; stk= x}, y
|x, Return {retreating= true; stk= y} -> |x, Return {retreating= true; stk= y} ->
compare_as_inlined_location x y compare_as_inlined_location x y
@ -81,9 +77,6 @@ end = struct
| Empty, Empty -> 0 | Empty, Empty -> 0
let rec print_abbrev fs = function let rec print_abbrev fs = function
| Locals (_, s) ->
print_abbrev fs s ;
Format.pp_print_char fs 'L'
| Return {retreating= false; stk= s} -> | Return {retreating= false; stk= s} ->
print_abbrev fs s ; print_abbrev fs s ;
Format.pp_print_char fs 'R' Format.pp_print_char fs 'R'
@ -99,23 +92,20 @@ end = struct
Invariant.invariant [%here] s [%sexp_of: t] Invariant.invariant [%here] s [%sexp_of: t]
@@ fun () -> @@ fun () ->
match s with match s with
| Locals _ | Return _ | Throw (_, Return _) | Empty -> () | Return _ | Throw (_, Return _) | Empty -> ()
| Throw _ -> fail "malformed stack: %a" print_abbrev s () | Throw _ -> fail "malformed stack: %a" print_abbrev s ()
let empty = Empty |> check invariant let empty = Empty |> check invariant
let push_jump lcls stk = let push_return ~retreating dst params locals from_call stk =
(if Set.is_empty lcls then stk else Locals (lcls, stk)) Return {retreating; dst; params; locals; from_call; stk}
|> check invariant |> check invariant
let push_return ~retreating dst params from_call stk =
Return {retreating; dst; params; from_call; stk} |> check invariant
let push_throw jmp stk = let push_throw jmp stk =
(match jmp with None -> stk | Some jmp -> Throw (jmp, stk)) (match jmp with None -> stk | Some jmp -> Throw (jmp, stk))
|> check invariant |> check invariant
let push_call {Llair.params; locals} ~retreating ~bound ~return from_call let push_call (entry : Llair.block) ~retreating ~bound ~return from_call
?throw stk = ?throw stk =
[%Trace.call fun {pf} -> pf "%a" print_abbrev stk] [%Trace.call fun {pf} -> pf "%a" print_abbrev stk]
; ;
@ -130,34 +120,28 @@ end = struct
( if n > bound then None ( if n > bound then None
else else
Some Some
(push_jump locals
(push_throw throw (push_throw throw
(push_return ~retreating return params from_call stk))) ) (push_return ~retreating return entry.params entry.parent.locals
from_call stk)) )
|> |>
[%Trace.retn fun {pf} _ -> [%Trace.retn fun {pf} _ ->
pf "%d of %a on stack" n Llair.Jump.pp return] pf "%d of %a on stack" n Llair.Jump.pp return]
let pop_return stk = let rec pop_return = function
let rec pop_return_ scope = function | Throw (_, stk) -> pop_return stk
| Locals (locals, stk) -> pop_return_ (Set.union locals scope) stk | Return {from_call; dst; stk} -> Some (from_call, dst, stk)
| Throw (_, stk) -> pop_return_ scope stk
| Return {from_call; dst; stk} -> Some (scope, from_call, dst, stk)
| Empty -> None | Empty -> None
in
pop_return_ Var.Set.empty stk
let pop_throw stk ~init ~unwind = let pop_throw stk ~init ~unwind =
let rec pop_throw_ scope state = function let rec pop_throw_ state = function
| Locals (locals, stk) -> | Return {params; locals; from_call; stk} ->
pop_throw_ (Set.union locals scope) state stk pop_throw_ (unwind params locals from_call state) stk
| Return {params; from_call; stk} ->
pop_throw_ Var.Set.empty (unwind params scope from_call state) stk
| Throw (dst, Return {from_call; stk}) -> | Throw (dst, Return {from_call; stk}) ->
Some (scope, from_call, dst, stk, state) Some (from_call, dst, stk, state)
| Empty -> None | Empty -> None
| Throw _ as stk -> violates invariant stk | Throw _ as stk -> violates invariant stk
in in
pop_throw_ Var.Set.empty init stk pop_throw_ init stk
end end
module Work : sig module Work : sig
@ -263,11 +247,10 @@ end = struct
end end
let exec_goto stk state block ({dst; retreating} : Llair.jump) = let exec_goto stk state block ({dst; retreating} : Llair.jump) =
let stk = Stack.push_jump dst.locals stk in
Work.add ~prev:block ~retreating stk state dst Work.add ~prev:block ~retreating stk state dst
let exec_jump ?temps stk state block ({dst; args} as jmp : Llair.jump) = let exec_jump ?temps stk state block ({dst; args} as jmp : Llair.jump) =
let state = Domain.jump args dst.params dst.locals ?temps state in let state = Domain.jump args dst.params ?temps state in
exec_goto stk state block jmp exec_goto stk state block jmp
let exec_call ~opts stk state block ({dst; args; retreating} : Llair.jump) let exec_call ~opts stk state block ({dst; args; retreating} : Llair.jump)
@ -276,7 +259,8 @@ let exec_call ~opts stk state block ({dst; args; retreating} : Llair.jump)
pf "%a from %a" Var.pp dst.parent.name.var Var.pp pf "%a from %a" Var.pp dst.parent.name.var Var.pp
return.dst.parent.name.var] return.dst.parent.name.var]
; ;
let state, from_call = Domain.call args dst.params dst.locals state in let locals = dst.parent.locals in
let state, from_call = Domain.call args dst.params locals state in
( match ( match
Stack.push_call ~bound:opts.bound dst ~retreating ~return from_call Stack.push_call ~bound:opts.bound dst ~retreating ~return from_call
?throw stk ?throw stk
@ -290,7 +274,7 @@ let exec_return stk pre_state (block : Llair.block) exp =
[%Trace.call fun {pf} -> pf "from %a" Var.pp block.parent.name.var] [%Trace.call fun {pf} -> pf "from %a" Var.pp block.parent.name.var]
; ;
( match Stack.pop_return stk with ( match Stack.pop_return stk with
| Some (scope, from_call, retn_site, stk) -> | Some (from_call, retn_site, stk) ->
let freturn = block.parent.freturn in let freturn = block.parent.freturn in
let exit_state = let exit_state =
match (freturn, exp) with match (freturn, exp) with
@ -299,7 +283,9 @@ let exec_return stk pre_state (block : Llair.block) exp =
| None, None -> pre_state | None, None -> pre_state
| _ -> violates Llair.Func.invariant block.parent | _ -> violates Llair.Func.invariant block.parent
in in
let post_state = Domain.post scope from_call exit_state in let post_state =
Domain.post block.parent.locals from_call exit_state
in
let retn_state = let retn_state =
Domain.retn block.parent.entry.params from_call post_state Domain.retn block.parent.entry.params from_call post_state
in in
@ -319,10 +305,12 @@ let exec_throw stk pre_state (block : Llair.block) exc =
Domain.retn params from_call (Domain.post scope from_call state) Domain.retn params from_call (Domain.post scope from_call state)
in in
( match Stack.pop_throw stk ~unwind ~init:pre_state with ( match Stack.pop_throw stk ~unwind ~init:pre_state with
| Some (scope, from_call, retn_site, stk, unwind_state) -> | Some (from_call, retn_site, stk, unwind_state) ->
let fthrow = block.parent.fthrow in let fthrow = block.parent.fthrow in
let exit_state = Domain.exec_return unwind_state fthrow exc in let exit_state = Domain.exec_return unwind_state fthrow exc in
let post_state = Domain.post scope from_call exit_state in let post_state =
Domain.post block.parent.locals from_call exit_state
in
let retn_state = let retn_state =
Domain.retn block.parent.entry.params from_call post_state Domain.retn block.parent.entry.params from_call post_state
in in
@ -441,10 +429,10 @@ let harness : Llair.t -> (int -> Work.t) option =
List.find_map entry_points ~f:(fun name -> List.find_map entry_points ~f:(fun name ->
Llair.Func.find pgm.functions (Var.program name) ) Llair.Func.find pgm.functions (Var.program name) )
|> function |> function
| Some {entry= {params= []} as block} -> | Some {locals; entry= {params= []} as block} ->
Some Some
(Work.init (Work.init
(fst (Domain.call [] [] block.locals (Domain.init pgm.globals))) (fst (Domain.call [] [] locals (Domain.init pgm.globals)))
block) block)
| _ -> None | _ -> None

@ -45,7 +45,6 @@ and term =
and block = and block =
{ lbl: label { lbl: label
; params: Var.t list ; params: Var.t list
; locals: Var.Set.t
; cmnd: cmnd ; cmnd: cmnd
; term: term ; term: term
; mutable parent: func ; mutable parent: func
@ -54,10 +53,10 @@ and block =
and cfg = block vector and cfg = block vector
(* [entry] is not part of [cfg] since it is special in several ways: its (* [entry] is not part of [cfg] since it is special in several ways: its
params are the func params, its locals are all the locals in it plus the params are the func params, and it cannot be jumped to, only called. *)
cfg, and it cannot be jumped to, only called. *)
and func = and func =
{ name: Global.t { name: Global.t
; locals: Var.Set.t
; entry: block ; entry: block
; cfg: cfg ; cfg: cfg
; freturn: Var.t option ; freturn: Var.t option
@ -94,11 +93,10 @@ let sexp_of_term = function
| Throw {exc; loc} -> sexp_ctor "Throw" [%sexp {exc: Exp.t; loc: Loc.t}] | Throw {exc; loc} -> sexp_ctor "Throw" [%sexp {exc: Exp.t; loc: Loc.t}]
| Unreachable -> Sexp.Atom "Unreachable" | Unreachable -> Sexp.Atom "Unreachable"
let sexp_of_block {lbl; params; locals; cmnd; term; parent; sort_index} = let sexp_of_block {lbl; params; cmnd; term; parent; sort_index} =
[%sexp [%sexp
{ lbl: label { lbl: label
; params: Var.t list ; params: Var.t list
; locals: Var.Set.t
; cmnd: cmnd ; cmnd: cmnd
; term: term ; term: term
; parent: Var.t = parent.name.var ; parent: Var.t = parent.name.var
@ -106,8 +104,8 @@ let sexp_of_block {lbl; params; locals; cmnd; term; parent; sort_index} =
let sexp_of_cfg v = [%sexp_of: block vector] v let sexp_of_cfg v = [%sexp_of: block vector] v
let sexp_of_func {name; entry; cfg} = let sexp_of_func {name; locals; entry; cfg} =
[%sexp {name: Global.t; entry: block; cfg: cfg}] [%sexp {name: Global.t; locals: Var.Set.t; entry: block; cfg: cfg}]
(* blocks in a [t] are uniquely identified by [sort_index] *) (* blocks in a [t] are uniquely identified by [sort_index] *)
let compare_block x y = Int.compare x.sort_index y.sort_index let compare_block x y = Int.compare x.sort_index y.sort_index
@ -199,7 +197,6 @@ let pp_block fs {lbl; params; cmnd; term; sort_index} =
let rec dummy_block = let rec dummy_block =
{ lbl= "dummy" { lbl= "dummy"
; params= [] ; params= []
; locals= Var.Set.empty
; cmnd= Vector.empty ; cmnd= Vector.empty
; term= Unreachable ; term= Unreachable
; parent= dummy_func ; parent= dummy_func
@ -209,6 +206,7 @@ and dummy_func =
let dummy_var = Var.program "dummy" in let dummy_var = Var.program "dummy" in
let dummy_ptr_typ = Typ.pointer ~elt:(Typ.opaque ~name:"dummy") in let dummy_ptr_typ = Typ.pointer ~elt:(Typ.opaque ~name:"dummy") in
{ name= Global.mk dummy_var dummy_ptr_typ Loc.none { name= Global.mk dummy_var dummy_ptr_typ Loc.none
; locals= Var.Set.empty
; entry= dummy_block ; entry= dummy_block
; cfg= Vector.empty ; cfg= Vector.empty
; freturn= None ; freturn= None
@ -354,12 +352,8 @@ module Block = struct
assert (not (List.contains_dup blk.params ~compare:Var.compare)) assert (not (List.contains_dup blk.params ~compare:Var.compare))
let mk ~lbl ~params ~cmnd ~term = let mk ~lbl ~params ~cmnd ~term =
let locals =
Vector.fold_right ~f:Inst.union_locals cmnd ~init:Var.Set.empty
in
{ lbl { lbl
; params ; params
; locals
; cmnd ; cmnd
; term ; term
; parent= dummy_block.parent ; parent= dummy_block.parent
@ -403,7 +397,7 @@ module Func = struct
Invariant.invariant [%here] func [%sexp_of: t] Invariant.invariant [%here] func [%sexp_of: t]
@@ fun () -> @@ fun () ->
assert (func == func.entry.parent) ; assert (func == func.entry.parent) ;
let {name= {typ}; cfg} = func in let {name= {typ}; entry; cfg} = func in
match typ with match typ with
| Pointer {elt= Function {return}} -> | Pointer {elt= Function {return}} ->
assert ( assert (
@ -413,8 +407,8 @@ module Func = struct
assert ( assert (
not not
(List.contains_dup (List.contains_dup
(List.concat_map (Vector.to_list cfg) ~f:(fun {params} -> (List.concat_map (entry :: Vector.to_list cfg) ~f:(fun blk ->
params )) blk.params ))
~compare:Var.compare) ) ; ~compare:Var.compare) ) ;
assert (Bool.(Option.is_some return = Option.is_some func.freturn)) ; assert (Bool.(Option.is_some return = Option.is_some func.freturn)) ;
iter_term func ~f:(fun term -> Term.invariant ~parent:func term) iter_term func ~f:(fun term -> Term.invariant ~parent:func term)
@ -424,10 +418,15 @@ module Func = struct
let mk ~(name : Global.t) ~entry ~cfg = let mk ~(name : Global.t) ~entry ~cfg =
let locals = let locals =
Vector.fold ~init:entry.locals cfg ~f:(fun locals block -> let locals_cmnd locals cmnd =
Set.add_list block.params (Set.union locals block.locals) ) Vector.fold_right ~f:Inst.union_locals cmnd ~init:locals
in
let locals_block locals block =
Set.add_list block.params (locals_cmnd locals block.cmnd)
in
let init = locals_cmnd Var.Set.empty entry.cmnd in
Vector.fold ~f:locals_block cfg ~init
in in
let entry = {entry with locals} in
let wrt = Set.add_list entry.params locals in let wrt = Set.add_list entry.params locals in
let freturn, wrt = let freturn, wrt =
match name.typ with match name.typ with
@ -437,7 +436,7 @@ module Func = struct
| _ -> (None, wrt) | _ -> (None, wrt)
in in
let fthrow, _ = Var.fresh "fthrow" ~wrt in let fthrow, _ = Var.fresh "fthrow" ~wrt in
let func = {name; entry; cfg; freturn; fthrow} in let func = {name; locals; entry; cfg; freturn; fthrow} in
let resolve_parent_and_jumps block = let resolve_parent_and_jumps block =
block.parent <- func ; block.parent <- func ;
let lookup cfg lbl : block = let lookup cfg lbl : block =

@ -95,7 +95,6 @@ and term = private
and block = private and block = private
{ lbl: label { lbl: label
; params: Var.t list (** Formal parameters, first-param-last stack *) ; params: Var.t list (** Formal parameters, first-param-last stack *)
; locals: Var.Set.t (** Local variables *)
; cmnd: cmnd ; cmnd: cmnd
; term: term ; term: term
; mutable parent: func ; mutable parent: func
@ -109,6 +108,7 @@ and cfg
parameters are the function parameters. *) parameters are the function parameters. *)
and func = private and func = private
{ name: Global.t { name: Global.t
; locals: Var.Set.t (** Local variables *)
; entry: block ; entry: block
; cfg: cfg ; cfg: cfg
; freturn: Var.t option ; freturn: Var.t option

@ -44,9 +44,9 @@ type from_call =
{state_from_call: State_domain.from_call; caller_entry: State_domain.t} {state_from_call: State_domain.from_call; caller_entry: State_domain.t}
[@@deriving sexp_of] [@@deriving sexp_of]
let jump actuals formals locals ?temps (entry, current) = let jump actuals formals ?temps (entry, current) =
let current, _ = let current, _ =
State_domain.call actuals formals locals ?temps current State_domain.call actuals formals Var.Set.empty ?temps current
in in
(entry, current) (entry, current)

@ -21,9 +21,7 @@ val exec_intrinsic :
type from_call [@@deriving sexp_of] type from_call [@@deriving sexp_of]
val jump : val jump : Exp.t list -> Var.t list -> ?temps:Var.Set.t -> t -> t
Exp.t list -> Var.t list -> Var.Set.t -> ?temps:Var.Set.t -> t -> t
val call : Exp.t list -> Var.t list -> Var.Set.t -> t -> t * from_call val call : Exp.t list -> Var.t list -> Var.Set.t -> t -> t * from_call
val post : Var.Set.t -> from_call -> t -> t val post : Var.Set.t -> from_call -> t -> t
val retn : Var.t list -> from_call -> t -> t val retn : Var.t list -> from_call -> t -> t

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