the scrutinee of the case, and we can inline it.
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
--- for details
-
module SetLevels (
setLevels,
import CoreSyn
-import DynFlags ( FloatOutSwitches(..) )
+import DynFlags ( FloatOutSwitches(..) )
import CoreUtils ( exprType, exprIsTrivial, mkPiTypes )
import CoreFVs -- all of it
import CoreSubst ( Subst, emptySubst, extendInScope, extendIdSubst,
cloneIdBndr, cloneRecIdBndrs )
import Id ( Id, idType, mkSysLocal, isOneShotLambda,
- zapDemandIdInfo,
+ zapDemandIdInfo, transferPolyIdInfo,
idSpecialisation, idWorkerInfo, setIdInfo
)
-import IdInfo ( workerExists, vanillaIdInfo, isEmptySpecInfo )
-import Var ( Var )
+import IdInfo
+import Var
import VarSet
import VarEnv
import Name ( getOccName )
context @Level 0 0@.
-InlineCtxt
-~~~~~~~~~~
+Note [FloatOut inside INLINE]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@InlineCtxt@ very similar to @Level 0 0@, but is used for one purpose:
to say "don't float anything out of here". That's exactly what we
want for the body of an INLINE, where we don't want to float anything
type LevelledExpr = TaggedExpr Level
type LevelledBind = TaggedBind Level
+tOP_LEVEL, iNLINE_CTXT :: Level
tOP_LEVEL = Level 0 0
iNLINE_CTXT = InlineCtxt
incMajorLvl :: Level -> Level
-- For InlineCtxt we ignore any inc's; we don't want
-- to do any floating at all; see notes above
-incMajorLvl InlineCtxt = InlineCtxt
-incMajorLvl (Level major minor) = Level (major+1) 0
+incMajorLvl InlineCtxt = InlineCtxt
+incMajorLvl (Level major _) = Level (major + 1) 0
incMinorLvl :: Level -> Level
incMinorLvl InlineCtxt = InlineCtxt
| otherwise = l2
ltLvl :: Level -> Level -> Bool
-ltLvl any_lvl InlineCtxt = False
+ltLvl _ InlineCtxt = False
ltLvl InlineCtxt (Level _ _) = True
ltLvl (Level maj1 min1) (Level maj2 min2)
= (maj1 < maj2) || (maj1 == maj2 && min1 < min2)
ltMajLvl :: Level -> Level -> Bool
-- Tells if one level belongs to a difft *lambda* level to another
-ltMajLvl any_lvl InlineCtxt = False
-ltMajLvl InlineCtxt (Level maj2 _) = 0 < maj2
+ltMajLvl _ InlineCtxt = False
+ltMajLvl InlineCtxt (Level maj2 _) = 0 < maj2
ltMajLvl (Level maj1 _) (Level maj2 _) = maj1 < maj2
isTopLvl :: Level -> Bool
isTopLvl (Level 0 0) = True
-isTopLvl other = False
+isTopLvl _ = False
isInlineCtxt :: Level -> Bool
isInlineCtxt InlineCtxt = True
-isInlineCtxt other = False
+isInlineCtxt _ = False
instance Outputable Level where
ppr InlineCtxt = text "<INLINE>"
ppr (Level maj min) = hcat [ char '<', int maj, char ',', int min, char '>' ]
instance Eq Level where
- InlineCtxt == InlineCtxt = True
- (Level maj1 min1) == (Level maj2 min2) = maj1==maj2 && min1==min2
- l1 == l2 = False
+ InlineCtxt == InlineCtxt = True
+ (Level maj1 min1) == (Level maj2 min2) = maj1 == maj2 && min1 == min2
+ _ == _ = False
\end{code}
-- things unbound in the envt have level number zero implicitly
do_them :: [CoreBind] -> LvlM [LevelledBind]
- do_them [] = returnLvl []
- do_them (b:bs)
- = lvlTopBind init_env b `thenLvl` \ (lvld_bind, _) ->
- do_them bs `thenLvl` \ lvld_binds ->
- returnLvl (lvld_bind : lvld_binds)
+ do_them [] = return []
+ do_them (b:bs) = do
+ (lvld_bind, _) <- lvlTopBind init_env b
+ lvld_binds <- do_them bs
+ return (lvld_bind : lvld_binds)
init_env = initialEnv float_lams
+lvlTopBind :: LevelEnv -> Bind Id -> LvlM (LevelledBind, LevelEnv)
lvlTopBind env (NonRec binder rhs)
= lvlBind TopLevel tOP_LEVEL env (AnnNonRec binder (freeVars rhs))
-- Rhs can have no free vars!
If there were another lambda in @r@'s rhs, it would get level-2 as well.
\begin{code}
-lvlExpr _ _ (_, AnnType ty) = returnLvl (Type ty)
-lvlExpr _ env (_, AnnVar v) = returnLvl (lookupVar env v)
-lvlExpr _ env (_, AnnLit lit) = returnLvl (Lit lit)
-
-lvlExpr ctxt_lvl env (_, AnnApp fun arg)
- = lvl_fun fun `thenLvl` \ fun' ->
- lvlMFE False ctxt_lvl env arg `thenLvl` \ arg' ->
- returnLvl (App fun' arg')
+lvlExpr _ _ ( _, AnnType ty) = return (Type ty)
+lvlExpr _ env (_, AnnVar v) = return (lookupVar env v)
+lvlExpr _ _ (_, AnnLit lit) = return (Lit lit)
+
+lvlExpr ctxt_lvl env (_, AnnApp fun arg) = do
+ fun' <- lvl_fun fun
+ arg' <- lvlMFE False ctxt_lvl env arg
+ return (App fun' arg')
where
-- gaw 2004
lvl_fun (_, AnnCase _ _ _ _) = lvlMFE True ctxt_lvl env fun
- lvl_fun other = lvlExpr ctxt_lvl env fun
+ lvl_fun _ = lvlExpr ctxt_lvl env fun
-- We don't do MFE on partial applications generally,
-- but we do if the function is big and hairy, like a case
-lvlExpr ctxt_lvl env (_, AnnNote InlineMe expr)
+lvlExpr _ env (_, AnnNote InlineMe expr) = do
-- Don't float anything out of an InlineMe; hence the iNLINE_CTXT
- = lvlExpr iNLINE_CTXT env expr `thenLvl` \ expr' ->
- returnLvl (Note InlineMe expr')
+ expr' <- lvlExpr iNLINE_CTXT env expr
+ return (Note InlineMe expr')
-lvlExpr ctxt_lvl env (_, AnnNote note expr)
- = lvlExpr ctxt_lvl env expr `thenLvl` \ expr' ->
- returnLvl (Note note expr')
+lvlExpr ctxt_lvl env (_, AnnNote note expr) = do
+ expr' <- lvlExpr ctxt_lvl env expr
+ return (Note note expr')
-lvlExpr ctxt_lvl env (_, AnnCast expr co)
- = lvlExpr ctxt_lvl env expr `thenLvl` \ expr' ->
- returnLvl (Cast expr' co)
+lvlExpr ctxt_lvl env (_, AnnCast expr co) = do
+ expr' <- lvlExpr ctxt_lvl env expr
+ return (Cast expr' co)
-- We don't split adjacent lambdas. That is, given
-- \x y -> (x+1,y)
-- Why not? Because partial applications are fairly rare, and splitting
-- lambdas makes them more expensive.
-lvlExpr ctxt_lvl env expr@(_, AnnLam bndr rhs)
- = lvlMFE True new_lvl new_env body `thenLvl` \ new_body ->
- returnLvl (mkLams new_bndrs new_body)
+lvlExpr ctxt_lvl env expr@(_, AnnLam {}) = do
+ new_body <- lvlMFE True new_lvl new_env body
+ return (mkLams new_bndrs new_body)
where
(bndrs, body) = collectAnnBndrs expr
(new_lvl, new_bndrs) = lvlLamBndrs ctxt_lvl bndrs
-- [See SetLevels rev 1.50 for a version with this approach.]
lvlExpr ctxt_lvl env (_, AnnLet (AnnNonRec bndr rhs) body)
- | isUnLiftedType (idType bndr)
+ | isUnLiftedType (idType bndr) = do
-- Treat unlifted let-bindings (let x = b in e) just like (case b of x -> e)
-- That is, leave it exactly where it is
-- We used to float unlifted bindings too (e.g. to get a cheap primop
-- but an unrelated change meant that these unlifed bindings
-- could get to the top level which is bad. And there's not much point;
-- unlifted bindings are always cheap, and so hardly worth floating.
- = lvlExpr ctxt_lvl env rhs `thenLvl` \ rhs' ->
- lvlExpr incd_lvl env' body `thenLvl` \ body' ->
- returnLvl (Let (NonRec bndr' rhs') body')
+ rhs' <- lvlExpr ctxt_lvl env rhs
+ body' <- lvlExpr incd_lvl env' body
+ return (Let (NonRec bndr' rhs') body')
where
incd_lvl = incMinorLvl ctxt_lvl
bndr' = TB bndr incd_lvl
env' = extendLvlEnv env [bndr']
-lvlExpr ctxt_lvl env (_, AnnLet bind body)
- = lvlBind NotTopLevel ctxt_lvl env bind `thenLvl` \ (bind', new_env) ->
- lvlExpr ctxt_lvl new_env body `thenLvl` \ body' ->
- returnLvl (Let bind' body')
+lvlExpr ctxt_lvl env (_, AnnLet bind body) = do
+ (bind', new_env) <- lvlBind NotTopLevel ctxt_lvl env bind
+ body' <- lvlExpr ctxt_lvl new_env body
+ return (Let bind' body')
-lvlExpr ctxt_lvl env (_, AnnCase expr case_bndr ty alts)
- = lvlMFE True ctxt_lvl env expr `thenLvl` \ expr' ->
- let
- alts_env = extendCaseBndrLvlEnv env expr' case_bndr incd_lvl
- in
- mapLvl (lvl_alt alts_env) alts `thenLvl` \ alts' ->
- returnLvl (Case expr' (TB case_bndr incd_lvl) ty alts')
+lvlExpr ctxt_lvl env (_, AnnCase expr case_bndr ty alts) = do
+ expr' <- lvlMFE True ctxt_lvl env expr
+ let alts_env = extendCaseBndrLvlEnv env expr' case_bndr incd_lvl
+ alts' <- mapM (lvl_alt alts_env) alts
+ return (Case expr' (TB case_bndr incd_lvl) ty alts')
where
incd_lvl = incMinorLvl ctxt_lvl
- lvl_alt alts_env (con, bs, rhs)
- = lvlMFE True incd_lvl new_env rhs `thenLvl` \ rhs' ->
- returnLvl (con, bs', rhs')
- where
- bs' = [ TB b incd_lvl | b <- bs ]
- new_env = extendLvlEnv alts_env bs'
+ lvl_alt alts_env (con, bs, rhs) = do
+ rhs' <- lvlMFE True incd_lvl new_env rhs
+ return (con, bs', rhs')
+ where
+ bs' = [ TB b incd_lvl | b <- bs ]
+ new_env = extendLvlEnv alts_env bs'
\end{code}
@lvlMFE@ is just like @lvlExpr@, except that it might let-bind
-> CoreExprWithFVs -- input expression
-> LvlM LevelledExpr -- Result expression
-lvlMFE strict_ctxt ctxt_lvl env (_, AnnType ty)
- = returnLvl (Type ty)
+lvlMFE _ _ _ (_, AnnType ty)
+ = return (Type ty)
lvlMFE strict_ctxt ctxt_lvl env ann_expr@(fvs, _)
lvlExpr ctxt_lvl env ann_expr
| otherwise -- Float it out!
- = lvlFloatRhs abs_vars dest_lvl env ann_expr `thenLvl` \ expr' ->
- newLvlVar "lvl" abs_vars ty `thenLvl` \ var ->
- returnLvl (Let (NonRec (TB var dest_lvl) expr')
- (mkVarApps (Var var) abs_vars))
+ = do expr' <- lvlFloatRhs abs_vars dest_lvl env ann_expr
+ var <- newLvlVar "lvl" abs_vars ty
+ return (Let (NonRec (TB var dest_lvl) expr')
+ (mkVarApps (Var var) abs_vars))
where
expr = deAnnotate ann_expr
ty = exprType expr
lvlBind top_lvl ctxt_lvl env (AnnNonRec bndr rhs@(rhs_fvs,_))
| isInlineCtxt ctxt_lvl -- Don't do anything inside InlineMe
- = lvlExpr ctxt_lvl env rhs `thenLvl` \ rhs' ->
- returnLvl (NonRec (TB bndr ctxt_lvl) rhs', env)
+ = do rhs' <- lvlExpr ctxt_lvl env rhs
+ return (NonRec (TB bndr ctxt_lvl) rhs', env)
| null abs_vars
- = -- No type abstraction; clone existing binder
- lvlExpr dest_lvl env rhs `thenLvl` \ rhs' ->
- cloneVar top_lvl env bndr ctxt_lvl dest_lvl `thenLvl` \ (env', bndr') ->
- returnLvl (NonRec (TB bndr' dest_lvl) rhs', env')
+ = do -- No type abstraction; clone existing binder
+ rhs' <- lvlExpr dest_lvl env rhs
+ (env', bndr') <- cloneVar top_lvl env bndr ctxt_lvl dest_lvl
+ return (NonRec (TB bndr' dest_lvl) rhs', env')
| otherwise
- = -- Yes, type abstraction; create a new binder, extend substitution, etc
- lvlFloatRhs abs_vars dest_lvl env rhs `thenLvl` \ rhs' ->
- newPolyBndrs dest_lvl env abs_vars [bndr] `thenLvl` \ (env', [bndr']) ->
- returnLvl (NonRec (TB bndr' dest_lvl) rhs', env')
+ = do -- Yes, type abstraction; create a new binder, extend substitution, etc
+ rhs' <- lvlFloatRhs abs_vars dest_lvl env rhs
+ (env', [bndr']) <- newPolyBndrs dest_lvl env abs_vars [bndr]
+ return (NonRec (TB bndr' dest_lvl) rhs', env')
where
bind_fvs = rhs_fvs `unionVarSet` idFreeVars bndr
\begin{code}
lvlBind top_lvl ctxt_lvl env (AnnRec pairs)
| isInlineCtxt ctxt_lvl -- Don't do anything inside InlineMe
- = mapLvl (lvlExpr ctxt_lvl env) rhss `thenLvl` \ rhss' ->
- returnLvl (Rec ([TB b ctxt_lvl | b <- bndrs] `zip` rhss'), env)
+ = do rhss' <- mapM (lvlExpr ctxt_lvl env) rhss
+ return (Rec ([TB b ctxt_lvl | b <- bndrs] `zip` rhss'), env)
| null abs_vars
- = cloneRecVars top_lvl env bndrs ctxt_lvl dest_lvl `thenLvl` \ (new_env, new_bndrs) ->
- mapLvl (lvlExpr ctxt_lvl new_env) rhss `thenLvl` \ new_rhss ->
- returnLvl (Rec ([TB b dest_lvl | b <- new_bndrs] `zip` new_rhss), new_env)
+ = do (new_env, new_bndrs) <- cloneRecVars top_lvl env bndrs ctxt_lvl dest_lvl
+ new_rhss <- mapM (lvlExpr ctxt_lvl new_env) rhss
+ return (Rec ([TB b dest_lvl | b <- new_bndrs] `zip` new_rhss), new_env)
| isSingleton pairs && count isId abs_vars > 1
- = -- Special case for self recursion where there are
+ = do -- Special case for self recursion where there are
-- several variables carried around: build a local loop:
-- poly_f = \abs_vars. \lam_vars . letrec f = \lam_vars. rhs in f lam_vars
-- This just makes the closures a bit smaller. If we don't do
--
-- This all seems a bit ad hoc -- sigh
let
- (bndr,rhs) = head pairs
- (rhs_lvl, abs_vars_w_lvls) = lvlLamBndrs dest_lvl abs_vars
- rhs_env = extendLvlEnv env abs_vars_w_lvls
- in
- cloneVar NotTopLevel rhs_env bndr rhs_lvl rhs_lvl `thenLvl` \ (rhs_env', new_bndr) ->
+ (bndr,rhs) = head pairs
+ (rhs_lvl, abs_vars_w_lvls) = lvlLamBndrs dest_lvl abs_vars
+ rhs_env = extendLvlEnv env abs_vars_w_lvls
+ (rhs_env', new_bndr) <- cloneVar NotTopLevel rhs_env bndr rhs_lvl rhs_lvl
let
- (lam_bndrs, rhs_body) = collectAnnBndrs rhs
+ (lam_bndrs, rhs_body) = collectAnnBndrs rhs
(body_lvl, new_lam_bndrs) = lvlLamBndrs rhs_lvl lam_bndrs
- body_env = extendLvlEnv rhs_env' new_lam_bndrs
- in
- lvlExpr body_lvl body_env rhs_body `thenLvl` \ new_rhs_body ->
- newPolyBndrs dest_lvl env abs_vars [bndr] `thenLvl` \ (poly_env, [poly_bndr]) ->
- returnLvl (Rec [(TB poly_bndr dest_lvl,
- mkLams abs_vars_w_lvls $
- mkLams new_lam_bndrs $
- Let (Rec [(TB new_bndr rhs_lvl, mkLams new_lam_bndrs new_rhs_body)])
- (mkVarApps (Var new_bndr) lam_bndrs))],
- poly_env)
-
- | otherwise -- Non-null abs_vars
- = newPolyBndrs dest_lvl env abs_vars bndrs `thenLvl` \ (new_env, new_bndrs) ->
- mapLvl (lvlFloatRhs abs_vars dest_lvl new_env) rhss `thenLvl` \ new_rhss ->
- returnLvl (Rec ([TB b dest_lvl | b <- new_bndrs] `zip` new_rhss), new_env)
+ body_env = extendLvlEnv rhs_env' new_lam_bndrs
+ new_rhs_body <- lvlExpr body_lvl body_env rhs_body
+ (poly_env, [poly_bndr]) <- newPolyBndrs dest_lvl env abs_vars [bndr]
+ return (Rec [(TB poly_bndr dest_lvl,
+ mkLams abs_vars_w_lvls $
+ mkLams new_lam_bndrs $
+ Let (Rec [(TB new_bndr rhs_lvl, mkLams new_lam_bndrs new_rhs_body)])
+ (mkVarApps (Var new_bndr) lam_bndrs))],
+ poly_env)
+
+ | otherwise = do -- Non-null abs_vars
+ (new_env, new_bndrs) <- newPolyBndrs dest_lvl env abs_vars bndrs
+ new_rhss <- mapM (lvlFloatRhs abs_vars dest_lvl new_env) rhss
+ return (Rec ([TB b dest_lvl | b <- new_bndrs] `zip` new_rhss), new_env)
where
(bndrs,rhss) = unzip pairs
----------------------------------------------------
-- Three help functons for the type-abstraction case
-lvlFloatRhs abs_vars dest_lvl env rhs
- = lvlExpr rhs_lvl rhs_env rhs `thenLvl` \ rhs' ->
- returnLvl (mkLams abs_vars_w_lvls rhs')
+lvlFloatRhs :: [CoreBndr] -> Level -> LevelEnv -> CoreExprWithFVs
+ -> UniqSM (Expr (TaggedBndr Level))
+lvlFloatRhs abs_vars dest_lvl env rhs = do
+ rhs' <- lvlExpr rhs_lvl rhs_env rhs
+ return (mkLams abs_vars_w_lvls rhs')
where
(rhs_lvl, abs_vars_w_lvls) = lvlLamBndrs dest_lvl abs_vars
rhs_env = extendLvlEnv env abs_vars_w_lvls
-- variables. We certainly only want to do it for values, and not for
-- constructors. So the simple thing is just to look for lambdas
isFunction (_, AnnLam b e) | isId b = True
- | otherwise = isFunction e
-isFunction (_, AnnNote n e) = isFunction e
-isFunction other = False
+ | otherwise = isFunction e
+isFunction (_, AnnNote _ e) = isFunction e
+isFunction _ = False
\end{code}
-- We also use these envs when making a variable polymorphic
-- because we want to float it out past a big lambda.
--
- -- The SubstEnv and IdEnv always implement the same mapping, but the
- -- SubstEnv maps to CoreExpr and the IdEnv to LevelledExpr
+ -- The Subst and IdEnv always implement the same mapping, but the
+ -- Subst maps to CoreExpr and the IdEnv to LevelledExpr
-- Since the range is always a variable or type application,
-- there is never any difference between the two, but sadly
-- the types differ. The SubstEnv is used when substituting in
-- extendCaseBndrLvlEnv adds the mapping case-bndr->scrut-var if it can
-- (see point 4 of the module overview comment)
+extendCaseBndrLvlEnv :: LevelEnv -> Expr (TaggedBndr Level) -> Var -> Level
+ -> LevelEnv
extendCaseBndrLvlEnv (float_lams, lvl_env, subst, id_env) (Var scrut_var) case_bndr lvl
= (float_lams,
extendVarEnv lvl_env case_bndr lvl,
extendIdSubst subst case_bndr (Var scrut_var),
extendVarEnv id_env case_bndr ([scrut_var], Var scrut_var))
-extendCaseBndrLvlEnv env scrut case_bndr lvl
+extendCaseBndrLvlEnv env _scrut case_bndr lvl
= extendLvlEnv env [TB case_bndr lvl]
+extendPolyLvlEnv :: Level -> LevelEnv -> [Var] -> [(Var, Var)] -> LevelEnv
extendPolyLvlEnv dest_lvl (float_lams, lvl_env, subst, id_env) abs_vars bndr_pairs
= (float_lams,
foldl add_lvl lvl_env bndr_pairs,
foldl add_subst subst bndr_pairs,
foldl add_id id_env bndr_pairs)
where
- add_lvl env (v,v') = extendVarEnv env v' dest_lvl
- add_subst env (v,v') = extendIdSubst env v (mkVarApps (Var v') abs_vars)
- add_id env (v,v') = extendVarEnv env v ((v':abs_vars), mkVarApps (Var v') abs_vars)
+ add_lvl env (_, v') = extendVarEnv env v' dest_lvl
+ add_subst env (v, v') = extendIdSubst env v (mkVarApps (Var v') abs_vars)
+ add_id env (v, v') = extendVarEnv env v ((v':abs_vars), mkVarApps (Var v') abs_vars)
+extendCloneLvlEnv :: Level -> LevelEnv -> Subst -> [(Var, Var)] -> LevelEnv
extendCloneLvlEnv lvl (float_lams, lvl_env, _, id_env) new_subst bndr_pairs
= (float_lams,
foldl add_lvl lvl_env bndr_pairs,
new_subst,
foldl add_id id_env bndr_pairs)
where
- add_lvl env (v,v') = extendVarEnv env v' lvl
- add_id env (v,v') = extendVarEnv env v ([v'], Var v')
+ add_lvl env (_, v') = extendVarEnv env v' lvl
+ add_id env (v, v') = extendVarEnv env v ([v'], Var v')
maxIdLevel :: LevelEnv -> VarSet -> Level
lookupVar :: LevelEnv -> Id -> LevelledExpr
lookupVar (_, _, _, id_env) v = case lookupVarEnv id_env v of
Just (_, expr) -> expr
- other -> Var v
+ _ -> Var v
abstractVars :: Level -> LevelEnv -> VarSet -> [Var]
-- Find the variables in fvs, free vars of the target expresion,
-- whose level is greater than the destination level
-- These are the ones we are going to abstract out
-abstractVars dest_lvl env fvs
- = uniq (sortLe le [var | fv <- varSetElems fvs, var <- absVarsOf dest_lvl env fv])
+abstractVars dest_lvl (_, lvl_env, _, id_env) fvs
+ = map zap $ uniq $ sortLe le
+ [var | fv <- varSetElems fvs
+ , var <- absVarsOf id_env fv
+ , abstract_me var ]
+ -- NB: it's important to call abstract_me only on the OutIds the
+ -- come from absVarsOf (not on fv, which is an InId)
where
- -- Sort the variables so we don't get
- -- mixed-up tyvars and Ids; it's just messy
- v1 `le` v2 = case (isId v1, isId v2) of
- (True, False) -> False
- (False, True) -> True
- other -> v1 <= v2 -- Same family
+ -- Sort the variables so the true type variables come first;
+ -- the tyvars scope over Ids and coercion vars
+ v1 `le` v2 = case (is_tv v1, is_tv v2) of
+ (True, False) -> True
+ (False, True) -> False
+ _ -> v1 <= v2 -- Same family
+
+ is_tv v = isTyVar v && not (isCoVar v)
uniq :: [Var] -> [Var]
-- Remove adjacent duplicates; the sort will have brought them together
| otherwise = v1 : uniq (v2:vs)
uniq vs = vs
-absVarsOf :: Level -> LevelEnv -> Var -> [Var]
- -- If f is free in the expression, and f maps to poly_f a b c in the
- -- current substitution, then we must report a b c as candidate type
- -- variables
-absVarsOf dest_lvl (_, lvl_env, _, id_env) v
- | isId v
- = [zap av2 | av1 <- lookup_avs v, av2 <- add_tyvars av1, abstract_me av2]
-
- | otherwise
- = if abstract_me v then [v] else []
-
- where
abstract_me v = case lookupVarEnv lvl_env v of
Just lvl -> dest_lvl `ltLvl` lvl
Nothing -> False
- lookup_avs v = case lookupVarEnv id_env v of
- Just (abs_vars, _) -> abs_vars
- Nothing -> [v]
-
- add_tyvars v = v : varSetElems (varTypeTyVars v)
-
-- We are going to lambda-abstract, so nuke any IdInfo,
-- and add the tyvars of the Id (if necessary)
zap v | isId v = WARN( workerExists (idWorkerInfo v) ||
text "absVarsOf: discarding info on" <+> ppr v )
setIdInfo v vanillaIdInfo
| otherwise = v
+
+absVarsOf :: IdEnv ([Var], LevelledExpr) -> Var -> [Var]
+ -- If f is free in the expression, and f maps to poly_f a b c in the
+ -- current substitution, then we must report a b c as candidate type
+ -- variables
+ --
+ -- Also, if x::a is an abstracted variable, then so is a; that is,
+ -- we must look in x's type
+ -- And similarly if x is a coercion variable.
+absVarsOf id_env v
+ | isId v = [av2 | av1 <- lookup_avs v
+ , av2 <- add_tyvars av1]
+ | isCoVar v = add_tyvars v
+ | otherwise = [v]
+
+ where
+ lookup_avs v = case lookupVarEnv id_env v of
+ Just (abs_vars, _) -> abs_vars
+ Nothing -> [v]
+
+ add_tyvars v = v : varSetElems (varTypeTyVars v)
\end{code}
\begin{code}
type LvlM result = UniqSM result
-initLvl = initUs_
-thenLvl = thenUs
-returnLvl = returnUs
-mapLvl = mapUs
+initLvl :: UniqSupply -> UniqSM a -> a
+initLvl = initUs_
\end{code}
+
\begin{code}
-newPolyBndrs dest_lvl env abs_vars bndrs
- = getUniquesUs `thenLvl` \ uniqs ->
- let
- new_bndrs = zipWith mk_poly_bndr bndrs uniqs
- in
- returnLvl (extendPolyLvlEnv dest_lvl env abs_vars (bndrs `zip` new_bndrs), new_bndrs)
+newPolyBndrs :: Level -> LevelEnv -> [Var] -> [Id] -> UniqSM (LevelEnv, [Id])
+newPolyBndrs dest_lvl env abs_vars bndrs = do
+ uniqs <- getUniquesM
+ let new_bndrs = zipWith mk_poly_bndr bndrs uniqs
+ return (extendPolyLvlEnv dest_lvl env abs_vars (bndrs `zip` new_bndrs), new_bndrs)
where
- mk_poly_bndr bndr uniq = mkSysLocal (mkFastString str) uniq poly_ty
+ mk_poly_bndr bndr uniq = transferPolyIdInfo bndr $ -- Note [transferPolyIdInfo] in Id.lhs
+ mkSysLocal (mkFastString str) uniq poly_ty
where
str = "poly_" ++ occNameString (getOccName bndr)
poly_ty = mkPiTypes abs_vars (idType bndr)
-
newLvlVar :: String
-> [CoreBndr] -> Type -- Abstract wrt these bndrs
-> LvlM Id
-newLvlVar str vars body_ty
- = getUniqueUs `thenLvl` \ uniq ->
- returnUs (mkSysLocal (mkFastString str) uniq (mkPiTypes vars body_ty))
+newLvlVar str vars body_ty = do
+ uniq <- getUniqueM
+ return (mkSysLocal (mkFastString str) uniq (mkPiTypes vars body_ty))
-- The deeply tiresome thing is that we have to apply the substitution
-- to the rules inside each Id. Grr. But it matters.
cloneVar :: TopLevelFlag -> LevelEnv -> Id -> Level -> Level -> LvlM (LevelEnv, Id)
-cloneVar TopLevel env v ctxt_lvl dest_lvl
- = returnUs (env, v) -- Don't clone top level things
+cloneVar TopLevel env v _ _
+ = return (env, v) -- Don't clone top level things
cloneVar NotTopLevel env@(_,_,subst,_) v ctxt_lvl dest_lvl
- = ASSERT( isId v )
- getUs `thenLvl` \ us ->
+ = ASSERT( isId v ) do
+ us <- getUniqueSupplyM
let
(subst', v1) = cloneIdBndr subst us v
v2 = zap_demand ctxt_lvl dest_lvl v1
env' = extendCloneLvlEnv dest_lvl env subst' [(v,v2)]
- in
- returnUs (env', v2)
+ return (env', v2)
cloneRecVars :: TopLevelFlag -> LevelEnv -> [Id] -> Level -> Level -> LvlM (LevelEnv, [Id])
-cloneRecVars TopLevel env vs ctxt_lvl dest_lvl
- = returnUs (env, vs) -- Don't clone top level things
+cloneRecVars TopLevel env vs _ _
+ = return (env, vs) -- Don't clone top level things
cloneRecVars NotTopLevel env@(_,_,subst,_) vs ctxt_lvl dest_lvl
- = ASSERT( all isId vs )
- getUs `thenLvl` \ us ->
+ = ASSERT( all isId vs ) do
+ us <- getUniqueSupplyM
let
(subst', vs1) = cloneRecIdBndrs subst us vs
vs2 = map (zap_demand ctxt_lvl dest_lvl) vs1
env' = extendCloneLvlEnv dest_lvl env subst' (vs `zip` vs2)
- in
- returnUs (env', vs2)
+ return (env', vs2)
-- VERY IMPORTANT: we must zap the demand info
-- if the thing is going to float out past a lambda,
-- or if it's going to top level (where things can't be strict)
+zap_demand :: Level -> Level -> Id -> Id
zap_demand dest_lvl ctxt_lvl id
| ctxt_lvl == dest_lvl,
not (isTopLvl dest_lvl) = id -- Stays, and not going to top level
projects / ghc-hetmet.git / blobdiff