X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FsimplCore%2FSetLevels.lhs;h=21dca615c3a1d230bfde2c8ff1b0c9e2534f94d6;hp=c32b83ddb58e6cdd6050930dcc7396caf5aac21b;hb=c8c2f6bb7d79a2a6aeaa3233363fdf0bbbfad205;hpb=d95ce839533391e7118257537044f01cbb1d6694 diff --git a/compiler/simplCore/SetLevels.lhs b/compiler/simplCore/SetLevels.lhs index c32b83d..21dca61 100644 --- a/compiler/simplCore/SetLevels.lhs +++ b/compiler/simplCore/SetLevels.lhs @@ -54,27 +54,24 @@ module SetLevels ( #include "HsVersions.h" import CoreSyn - -import DynFlags ( FloatOutSwitches(..) ) -import CoreUtils ( exprType, exprIsTrivial, exprBotStrictness_maybe, mkPiTypes ) +import CoreMonad ( FloatOutSwitches(..) ) +import CoreUtils ( exprType, mkPiTypes ) +import CoreArity ( exprBotStrictness_maybe ) import CoreFVs -- all of it import CoreSubst ( Subst, emptySubst, extendInScope, extendInScopeList, extendIdSubst, cloneIdBndr, cloneRecIdBndrs ) -import Id ( Id, idType, mkSysLocal, isOneShotLambda, - zapDemandIdInfo, transferPolyIdInfo, - idSpecialisation, idUnfolding, setIdInfo, - setIdNewStrictness, setIdArity - ) +import Id import IdInfo import Var import VarSet import VarEnv -import Name ( getOccName ) +import Demand ( StrictSig, increaseStrictSigArity ) +import Name ( getOccName, mkSystemVarName ) import OccName ( occNameString ) import Type ( isUnLiftedType, Type ) -import BasicTypes ( TopLevelFlag(..) ) +import BasicTypes ( TopLevelFlag(..), Arity ) import UniqSupply -import Util ( sortLe, isSingleton, count ) +import Util import Outputable import FastString \end{code} @@ -246,25 +243,52 @@ If there were another lambda in @r@'s rhs, it would get level-2 as well. \begin{code} lvlExpr _ _ ( _, AnnType ty) = return (Type ty) +lvlExpr _ _ ( _, AnnCoercion co) = return (Coercion co) 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 _ = 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 expr@(_, AnnApp _ _) = do + let + (fun, args) = collectAnnArgs expr + -- + case fun of + -- float out partial applications. This is very beneficial + -- in some cases (-7% runtime -4% alloc over nofib -O2). + -- In order to float a PAP, there must be a function at the + -- head of the application, and the application must be + -- over-saturated with respect to the function's arity. + (_, AnnVar f) | floatPAPs env && + arity > 0 && arity < n_val_args -> + do + let (lapp, rargs) = left (n_val_args - arity) expr [] + rargs' <- mapM (lvlMFE False ctxt_lvl env) rargs + lapp' <- lvlMFE False ctxt_lvl env lapp + return (foldl App lapp' rargs') + where + n_val_args = count (isValArg . deAnnotate) args + arity = idArity f + + -- separate out the PAP that we are floating from the extra + -- arguments, by traversing the spine until we have collected + -- (n_val_args - arity) value arguments. + left 0 e rargs = (e, rargs) + left n (_, AnnApp f a) rargs + | isValArg (deAnnotate a) = left (n-1) f (a:rargs) + | otherwise = left n f (a:rargs) + left _ _ _ = panic "SetLevels.lvlExpr.left" + + -- No PAPs that we can float: just carry on with the + -- arguments and the function. + _otherwise -> do + args' <- mapM (lvlMFE False ctxt_lvl env) args + fun' <- lvlExpr ctxt_lvl env fun + return (foldl App fun' args') 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) = do +lvlExpr ctxt_lvl env (_, AnnCast expr (_, co)) = do expr' <- lvlExpr ctxt_lvl env expr return (Cast expr' co) @@ -345,10 +369,33 @@ If we see we'd like to float the call to error, to get lvl = error "urk" f = \x. g lvl -But, it's very helpful for lvl to get a strictness signature, so that, -for example, its unfolding is not exposed in interface files (unnecessary). -But this float-out might occur after strictness analysis. So we use the -cheap-and-cheerful exprBotStrictness_maybe function. +Furthermore, we want to float a bottoming expression even if it has free +variables: + f = \x. g (let v = h x in error ("urk" ++ v)) +Then we'd like to abstact over 'x' can float the whole arg of g: + lvl = \x. let v = h x in error ("urk" ++ v) + f = \x. g (lvl x) +See Maessen's paper 1999 "Bottom extraction: factoring error handling out +of functional programs" (unpublished I think). + +When we do this, we set the strictness and arity of the new bottoming +Id, so that it's properly exposed as such in the interface file, even if +this is all happening after strictness analysis. + +Note [Bottoming floats: eta expansion] c.f Note [Bottoming floats] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Tiresomely, though, the simplifier has an invariant that the manifest +arity of the RHS should be the same as the arity; but we can't call +etaExpand during SetLevels because it works over a decorated form of +CoreExpr. So we do the eta expansion later, in FloatOut. + +Note [Case MFEs] +~~~~~~~~~~~~~~~~ +We don't float a case expression as an MFE from a strict context. Why not? +Because in doing so we share a tiny bit of computation (the switch) but +in exchange we build a thunk, which is bad. This case reduces allocation +by 7% in spectral/puzzle (a rather strange benchmark) and 1.2% in real/fem. +Doesn't change any other allocation at all. \begin{code} lvlMFE :: Bool -- True <=> strict context [body of case or let] @@ -368,31 +415,33 @@ lvlMFE strict_ctxt ctxt_lvl env (_, AnnNote n e) = do { e' <- lvlMFE strict_ctxt ctxt_lvl env e ; return (Note n e') } -lvlMFE strict_ctxt ctxt_lvl env (_, AnnCast e co) +lvlMFE strict_ctxt ctxt_lvl env (_, AnnCast e (_, co)) = do { e' <- lvlMFE strict_ctxt ctxt_lvl env e ; return (Cast e' co) } +-- Note [Case MFEs] +lvlMFE True ctxt_lvl env e@(_, AnnCase {}) + = lvlExpr ctxt_lvl env e -- Don't share cases + lvlMFE strict_ctxt ctxt_lvl env ann_expr@(fvs, _) - | isUnLiftedType ty -- Can't let-bind it; see Note [Unlifted MFEs] - || exprIsTrivial expr -- Never float if it's trivial + | isUnLiftedType ty -- Can't let-bind it; see Note [Unlifted MFEs] + -- This includes coercions, which we don't + -- want to float anyway + || notWorthFloating ann_expr abs_vars || not good_destination = -- Don't float it out lvlExpr ctxt_lvl env ann_expr | otherwise -- Float it out! = do expr' <- lvlFloatRhs abs_vars dest_lvl env ann_expr - var <- newLvlVar "lvl" abs_vars ty - -- Note [Bottoming floats] - let var_w_str = case exprBotStrictness_maybe expr of - Just (arity,str) -> var `setIdArity` arity - `setIdNewStrictness` str - Nothing -> var - return (Let (NonRec (TB var_w_str dest_lvl) expr') - (mkVarApps (Var var_w_str) abs_vars)) + var <- newLvlVar abs_vars ty mb_bot + return (Let (NonRec (TB var dest_lvl) expr') + (mkVarApps (Var var) abs_vars)) where expr = deAnnotate ann_expr ty = exprType expr - dest_lvl = destLevel env fvs (isFunction ann_expr) + mb_bot = exprBotStrictness_maybe expr + dest_lvl = destLevel env fvs (isFunction ann_expr) mb_bot abs_vars = abstractVars dest_lvl env fvs -- A decision to float entails let-binding this thing, and we only do @@ -419,6 +468,44 @@ lvlMFE strict_ctxt ctxt_lvl env ann_expr@(fvs, _) -- concat = /\ a -> lvl a -- lvl = /\ a -> foldr ..a.. (++) [] -- which is pretty stupid. Hence the strict_ctxt test + +annotateBotStr :: Id -> Maybe (Arity, StrictSig) -> Id +annotateBotStr id Nothing = id +annotateBotStr id (Just (arity,sig)) = id `setIdArity` arity + `setIdStrictness` sig + +notWorthFloating :: CoreExprWithFVs -> [Var] -> Bool +-- Returns True if the expression would be replaced by +-- something bigger than it is now. For example: +-- abs_vars = tvars only: return True if e is trivial, +-- but False for anything bigger +-- abs_vars = [x] (an Id): return True for trivial, or an application (f x) +-- but False for (f x x) +-- +-- One big goal is that floating should be idempotent. Eg if +-- we replace e with (lvl79 x y) and then run FloatOut again, don't want +-- to replace (lvl79 x y) with (lvl83 x y)! + +notWorthFloating e abs_vars + = go e (count isId abs_vars) + where + go (_, AnnVar {}) n = n >= 0 + go (_, AnnLit {}) n = n >= 0 + go (_, AnnCast e _) n = go e n + go (_, AnnApp e arg) n + | (_, AnnType {}) <- arg = go e n + | (_, AnnCoercion {}) <- arg = go e n + | n==0 = False + | is_triv arg = go e (n-1) + | otherwise = False + go _ _ = False + + is_triv (_, AnnLit {}) = True -- Treat all literals as trivial + is_triv (_, AnnVar {}) = True -- (ie not worth floating) + is_triv (_, AnnCast e _) = is_triv e + is_triv (_, AnnApp e (_, AnnType {})) = is_triv e + is_triv (_, AnnApp e (_, AnnCoercion {})) = is_triv e + is_triv _ = False \end{code} Note [Escaping a value lambda] @@ -495,24 +582,28 @@ lvlBind top_lvl ctxt_lvl env (AnnNonRec bndr rhs@(rhs_fvs,_)) | otherwise = 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] + (env', [bndr']) <- newPolyBndrs dest_lvl env abs_vars [bndr_w_str] return (NonRec (TB bndr' dest_lvl) rhs', env') where - bind_fvs = rhs_fvs `unionVarSet` idFreeVars bndr - abs_vars = abstractVars dest_lvl env bind_fvs - dest_lvl = destLevel env bind_fvs (isFunction rhs) + bind_fvs = rhs_fvs `unionVarSet` idFreeVars bndr + abs_vars = abstractVars dest_lvl env bind_fvs + dest_lvl = destLevel env bind_fvs (isFunction rhs) mb_bot + mb_bot = exprBotStrictness_maybe (deAnnotate rhs) + bndr_w_str = annotateBotStr bndr mb_bot \end{code} \begin{code} lvlBind top_lvl ctxt_lvl env (AnnRec pairs) - | null abs_vars + | null abs_vars = 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 isIdVar abs_vars > 1 +-- ToDo: when enabling the floatLambda stuff, +-- I think we want to stop doing this + | isSingleton pairs && count isId abs_vars > 1 = 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 @@ -555,11 +646,11 @@ lvlBind top_lvl ctxt_lvl env (AnnRec pairs) `minusVarSet` mkVarSet bndrs - dest_lvl = destLevel env bind_fvs (all isFunction rhss) + dest_lvl = destLevel env bind_fvs (all isFunction rhss) Nothing abs_vars = abstractVars dest_lvl env bind_fvs ---------------------------------------------------- --- Three help functons for the type-abstraction case +-- Three help functions for the type-abstraction case lvlFloatRhs :: [CoreBndr] -> Level -> LevelEnv -> CoreExprWithFVs -> UniqSM (Expr (TaggedBndr Level)) @@ -587,37 +678,31 @@ lvlLamBndrs lvl [] = (lvl, []) lvlLamBndrs lvl bndrs - = go (incMinorLvl lvl) - False -- Havn't bumped major level in this group - [] bndrs + = (new_lvl, [TB bndr new_lvl | bndr <- bndrs]) + -- All the new binders get the same level, because + -- any floating binding is either going to float past + -- all or none. We never separate binders where - go old_lvl bumped_major rev_lvld_bndrs (bndr:bndrs) - | isIdVar bndr && -- Go to the next major level if this is a value binder, - not bumped_major && -- and we havn't already gone to the next level (one jump per group) - not (isOneShotLambda bndr) -- and it isn't a one-shot lambda - = go new_lvl True (TB bndr new_lvl : rev_lvld_bndrs) bndrs + new_lvl | any is_major bndrs = incMajorLvl lvl + | otherwise = incMinorLvl lvl - | otherwise - = go old_lvl bumped_major (TB bndr old_lvl : rev_lvld_bndrs) bndrs - - where - new_lvl = incMajorLvl old_lvl - - go old_lvl _ rev_lvld_bndrs [] - = (old_lvl, reverse rev_lvld_bndrs) - -- a lambda like this (\x -> coerce t (\s -> ...)) - -- This happens quite a bit in state-transformer programs + is_major bndr = isId bndr && not (isOneShotLambda bndr) \end{code} \begin{code} -- Destintion level is the max Id level of the expression -- (We'll abstract the type variables, if any.) -destLevel :: LevelEnv -> VarSet -> Bool -> Level -destLevel env fvs is_function - | floatLams env - && is_function = tOP_LEVEL -- Send functions to top level; see +destLevel :: LevelEnv -> VarSet -> Bool -> Maybe (Arity, StrictSig) -> Level +destLevel env fvs is_function mb_bot + | Just {} <- mb_bot = tOP_LEVEL -- Send bottoming bindings to the top + -- regardless; see Note [Bottoming floats] + | Just n_args <- floatLams env + , n_args > 0 -- n=0 case handled uniformly by the 'otherwise' case + , is_function + , countFreeIds fvs <= n_args + = tOP_LEVEL -- Send functions to top level; see -- the comments with isFunction - | otherwise = maxIdLevel env fvs + | otherwise = maxIdLevel env fvs isFunction :: CoreExprWithFVs -> Bool -- The idea here is that we want to float *functions* to @@ -634,10 +719,17 @@ isFunction :: CoreExprWithFVs -> Bool -- We may only want to do this if there are sufficiently few free -- 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) | isIdVar b = True +isFunction (_, AnnLam b e) | isId b = True | otherwise = isFunction e isFunction (_, AnnNote _ e) = isFunction e isFunction _ = False + +countFreeIds :: VarSet -> Int +countFreeIds = foldVarSet add 0 + where + add :: Var -> Int -> Int + add v n | isId v = n+1 + | otherwise = n \end{code} @@ -648,48 +740,55 @@ isFunction _ = False %************************************************************************ \begin{code} -type LevelEnv = (FloatOutSwitches, - VarEnv Level, -- Domain is *post-cloned* TyVars and Ids - Subst, -- Domain is pre-cloned Ids; tracks the in-scope set - -- so that subtitution is capture-avoiding - IdEnv ([Var], LevelledExpr)) -- Domain is pre-cloned Ids +data LevelEnv + = LE { le_switches :: FloatOutSwitches + , le_lvl_env :: VarEnv Level -- Domain is *post-cloned* TyVars and Ids + , le_subst :: Subst -- Domain is pre-cloned Ids; tracks the in-scope set + -- so that subtitution is capture-avoiding + , le_env :: IdEnv ([Var], LevelledExpr) -- Domain is pre-cloned Ids + } -- We clone let-bound variables so that they are still - -- distinct when floated out; hence the SubstEnv/IdEnv. + -- distinct when floated out; hence the le_subst/le_env. -- (see point 3 of the module overview comment). -- We also use these envs when making a variable polymorphic -- because we want to float it out past a big lambda. -- - -- The Subst and IdEnv always implement the same mapping, but the - -- Subst maps to CoreExpr and the IdEnv to LevelledExpr + -- The le_subst and le_env always implement the same mapping, but the + -- le_subst maps to CoreExpr and the le_env 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 - -- a variable's IdInfo; the IdEnv when we find a Var. + -- the types differ. The le_subst is used when substituting in + -- a variable's IdInfo; the le_env when we find a Var. -- - -- In addition the IdEnv records a list of tyvars free in the + -- In addition the le_env records a list of tyvars free in the -- type application, just so we don't have to call freeVars on -- the type application repeatedly. -- -- The domain of the both envs is *pre-cloned* Ids, though -- - -- The domain of the VarEnv Level is the *post-cloned* Ids + -- The domain of the le_lvl_env is the *post-cloned* Ids initialEnv :: FloatOutSwitches -> LevelEnv -initialEnv float_lams = (float_lams, emptyVarEnv, emptySubst, emptyVarEnv) +initialEnv float_lams + = LE { le_switches = float_lams, le_lvl_env = emptyVarEnv + , le_subst = emptySubst, le_env = emptyVarEnv } -floatLams :: LevelEnv -> Bool -floatLams (fos, _, _, _) = floatOutLambdas fos +floatLams :: LevelEnv -> Maybe Int +floatLams le = floatOutLambdas (le_switches le) floatConsts :: LevelEnv -> Bool -floatConsts (fos, _, _, _) = floatOutConstants fos +floatConsts le = floatOutConstants (le_switches le) + +floatPAPs :: LevelEnv -> Bool +floatPAPs le = floatOutPartialApplications (le_switches le) extendLvlEnv :: LevelEnv -> [TaggedBndr Level] -> LevelEnv -- Used when *not* cloning -extendLvlEnv (float_lams, lvl_env, subst, id_env) prs - = (float_lams, - foldl add_lvl lvl_env prs, - foldl del_subst subst prs, - foldl del_id id_env prs) +extendLvlEnv le@(LE { le_lvl_env = lvl_env, le_subst = subst, le_env = id_env }) + prs + = le { le_lvl_env = foldl add_lvl lvl_env prs + , le_subst = foldl del_subst subst prs + , le_env = foldl del_id id_env prs } where add_lvl env (TB v l) = extendVarEnv env v l del_subst env (TB v _) = extendInScope env v @@ -709,48 +808,50 @@ extendLvlEnv (float_lams, lvl_env, subst, id_env) prs -- KSW 2000-07. extendInScopeEnv :: LevelEnv -> Var -> LevelEnv -extendInScopeEnv (fl, le, subst, ids) v = (fl, le, extendInScope subst v, ids) +extendInScopeEnv le@(LE { le_subst = subst }) v + = le { le_subst = extendInScope subst v } extendInScopeEnvList :: LevelEnv -> [Var] -> LevelEnv -extendInScopeEnvList (fl, le, subst, ids) vs = (fl, le, extendInScopeList subst vs, ids) +extendInScopeEnvList le@(LE { le_subst = subst }) vs + = le { le_subst = extendInScopeList subst vs } -- 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 le@(LE { le_lvl_env = lvl_env, le_subst = subst, le_env = id_env }) + (Var scrut_var) case_bndr lvl + = le { le_lvl_env = extendVarEnv lvl_env case_bndr lvl + , le_subst = extendIdSubst subst case_bndr (Var scrut_var) + , le_env = extendVarEnv id_env case_bndr ([scrut_var], Var scrut_var) } extendCaseBndrLvlEnv env _scrut case_bndr lvl - = extendLvlEnv env [TB 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) +extendPolyLvlEnv dest_lvl + le@(LE { le_lvl_env = lvl_env, le_subst = subst, le_env = id_env }) + abs_vars bndr_pairs + = le { le_lvl_env = foldl add_lvl lvl_env bndr_pairs + , le_subst = foldl add_subst subst bndr_pairs + , le_env = foldl add_id id_env bndr_pairs } where 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) +extendCloneLvlEnv lvl le@(LE { le_lvl_env = lvl_env, le_env = id_env }) + new_subst bndr_pairs + = le { le_lvl_env = foldl add_lvl lvl_env bndr_pairs + , le_subst = new_subst + , le_env = foldl add_id id_env bndr_pairs } where add_lvl env (_, v') = extendVarEnv env v' lvl add_id env (v, v') = extendVarEnv env v ([v'], Var v') - maxIdLevel :: LevelEnv -> VarSet -> Level -maxIdLevel (_, lvl_env,_,id_env) var_set +maxIdLevel (LE { le_lvl_env = lvl_env, le_env = id_env }) var_set = foldVarSet max_in tOP_LEVEL var_set where max_in in_var lvl = foldr max_out lvl (case lookupVarEnv id_env in_var of @@ -758,21 +859,21 @@ maxIdLevel (_, lvl_env,_,id_env) var_set Nothing -> [in_var]) max_out out_var lvl - | isIdVar out_var = case lookupVarEnv lvl_env out_var of + | isId out_var = case lookupVarEnv lvl_env out_var of Just lvl' -> maxLvl lvl' lvl Nothing -> lvl - | otherwise = lvl -- Ignore tyvars in *maxIdLevel* + | otherwise = lvl -- Ignore tyvars in *maxIdLevel* lookupVar :: LevelEnv -> Id -> LevelledExpr -lookupVar (_, _, _, id_env) v = case lookupVarEnv id_env v of - Just (_, expr) -> expr - _ -> Var v +lookupVar le v = case lookupVarEnv (le_env le) v of + Just (_, expr) -> expr + _ -> 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 (_, lvl_env, _, id_env) fvs +abstractVars dest_lvl (LE { le_lvl_env = lvl_env, le_env = id_env }) fvs = map zap $ uniq $ sortLe le [var | fv <- varSetElems fvs , var <- absVarsOf id_env fv @@ -787,7 +888,7 @@ abstractVars dest_lvl (_, lvl_env, _, id_env) fvs (False, True) -> False _ -> v1 <= v2 -- Same family - is_tv v = isTyVar v && not (isCoVar v) + is_tv v = isTyVar v uniq :: [Var] -> [Var] -- Remove adjacent duplicates; the sort will have brought them together @@ -801,7 +902,7 @@ abstractVars dest_lvl (_, lvl_env, _, id_env) fvs -- We are going to lambda-abstract, so nuke any IdInfo, -- and add the tyvars of the Id (if necessary) - zap v | isIdVar v = WARN( isInlineRule (idUnfolding v) || + zap v | isId v = WARN( isStableUnfolding (idUnfolding v) || not (isEmptySpecInfo (idSpecialisation v)), text "absVarsOf: discarding info on" <+> ppr v ) setIdInfo v vanillaIdInfo @@ -816,11 +917,9 @@ absVarsOf :: IdEnv ([Var], LevelledExpr) -> Var -> [Var] -- we must look in x's type -- And similarly if x is a coercion variable. absVarsOf id_env v - | isIdVar v = [av2 | av1 <- lookup_avs v + | isId v = [av2 | av1 <- lookup_avs v , av2 <- add_tyvars av1] - | isCoVar v = add_tyvars v - | otherwise = [v] - + | otherwise = ASSERT( isTyVar v ) [v] where lookup_avs v = case lookupVarEnv id_env v of Just (abs_vars, _) -> abs_vars @@ -844,18 +943,26 @@ newPolyBndrs dest_lvl env abs_vars bndrs = do 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 = transferPolyIdInfo bndr $ -- Note [transferPolyIdInfo] in Id.lhs + mk_poly_bndr bndr uniq = transferPolyIdInfo bndr abs_vars $ -- 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 +newLvlVar :: [CoreBndr] -> Type -- Abstract wrt these bndrs + -> Maybe (Arity, StrictSig) -- Note [Bottoming floats] -> LvlM Id -newLvlVar str vars body_ty = do - uniq <- getUniqueM - return (mkSysLocal (mkFastString str) uniq (mkPiTypes vars body_ty)) +newLvlVar vars body_ty mb_bot + = do { uniq <- getUniqueM + ; return (mkLocalIdWithInfo (mk_name uniq) (mkPiTypes vars body_ty) info) } + where + mk_name uniq = mkSystemVarName uniq (mkFastString "lvl") + arity = count isId vars + info = case mb_bot of + Nothing -> vanillaIdInfo + Just (bot_arity, sig) -> vanillaIdInfo + `setArityInfo` (arity + bot_arity) + `setStrictnessInfo` Just (increaseStrictSigArity arity sig) -- The deeply tiresome thing is that we have to apply the substitution -- to the rules inside each Id. Grr. But it matters. @@ -865,11 +972,11 @@ cloneVar TopLevel env v _ _ = return (extendInScopeEnv env v, v) -- Don't clone top level things -- But do extend the in-scope env, to satisfy the in-scope invariant -cloneVar NotTopLevel env@(_,_,subst,_) v ctxt_lvl dest_lvl - = ASSERT( isIdVar v ) do +cloneVar NotTopLevel env v ctxt_lvl dest_lvl + = ASSERT( isId v ) do us <- getUniqueSupplyM let - (subst', v1) = cloneIdBndr subst us v + (subst', v1) = cloneIdBndr (le_subst env) us v v2 = zap_demand ctxt_lvl dest_lvl v1 env' = extendCloneLvlEnv dest_lvl env subst' [(v,v2)] return (env', v2) @@ -877,11 +984,11 @@ cloneVar NotTopLevel env@(_,_,subst,_) v ctxt_lvl dest_lvl cloneRecVars :: TopLevelFlag -> LevelEnv -> [Id] -> Level -> Level -> LvlM (LevelEnv, [Id]) cloneRecVars TopLevel env vs _ _ = return (extendInScopeEnvList env vs, vs) -- Don't clone top level things -cloneRecVars NotTopLevel env@(_,_,subst,_) vs ctxt_lvl dest_lvl - = ASSERT( all isIdVar vs ) do +cloneRecVars NotTopLevel env vs ctxt_lvl dest_lvl + = ASSERT( all isId vs ) do us <- getUniqueSupplyM let - (subst', vs1) = cloneRecIdBndrs subst us vs + (subst', vs1) = cloneRecIdBndrs (le_subst env) us vs vs2 = map (zap_demand ctxt_lvl dest_lvl) vs1 env' = extendCloneLvlEnv dest_lvl env subst' (vs `zip` vs2) return (env', vs2)