\begin{code}
module SimplEnv (
- InId, InBind, InExpr, InAlt, InArg, InType, InBndr,
- OutId, OutTyVar, OutBind, OutExpr, OutAlt, OutArg, OutType, OutBndr,
+ InId, InBind, InExpr, InAlt, InArg, InType, InBndr, InVar,
+ OutId, OutTyVar, OutBind, OutExpr, OutAlt, OutArg, OutType, OutBndr, OutVar,
InCoercion, OutCoercion,
-- The simplifier mode
- setMode, getMode,
+ setMode, getMode, updMode,
-- Switch checker
SwitchChecker, SwitchResult(..), getSwitchChecker, getSimplIntSwitch,
setEnclosingCC, getEnclosingCC,
-- Environments
- SimplEnv(..), pprSimplEnv, -- Temp not abstract
+ SimplEnv(..), StaticEnv, pprSimplEnv, -- Temp not abstract
mkSimplEnv, extendIdSubst, SimplEnv.extendTvSubst,
zapSubstEnv, setSubstEnv,
getInScope, setInScope, setInScopeSet, modifyInScope, addNewInScopeIds,
- getSimplRules,
+ getSimplRules, inGentleMode,
SimplSR(..), mkContEx, substId, lookupRecBndr,
simplNonRecBndr, simplRecBndrs, simplLamBndr, simplLamBndrs,
simplBinder, simplBinders, addBndrRules,
- substExpr, substWorker, substTy,
+ substExpr, substTy, substTyVar, getTvSubst, mkCoreSubst,
-- Floats
Floats, emptyFloats, isEmptyFloats, addNonRec, addFloats, extendFloats,
#include "HsVersions.h"
import SimplMonad
+import CoreMonad ( SimplifierMode(..) )
import IdInfo
import CoreSyn
import CoreUtils
import VarSet
import OrdList
import Id
-import qualified CoreSubst ( Subst, mkSubst, substExpr, substSpec, substWorker )
-import qualified Type ( substTy, substTyVarBndr )
-import Type hiding ( substTy, substTyVarBndr )
+import qualified CoreSubst
+import qualified Type ( substTy, substTyVarBndr, substTyVar )
+import Type hiding ( substTy, substTyVarBndr, substTyVar )
import Coercion
import BasicTypes
-import DynFlags
import MonadUtils
import Outputable
import FastString
\begin{code}
type InBndr = CoreBndr
+type InVar = Var -- Not yet cloned
type InId = Id -- Not yet cloned
type InType = Type -- Ditto
type InBind = CoreBind
type InCoercion = Coercion
type OutBndr = CoreBndr
+type OutVar = Var -- Cloned
type OutId = Id -- Cloned
type OutTyVar = TyVar -- Cloned
type OutType = Type -- Cloned
\begin{code}
data SimplEnv
= SimplEnv {
+ ----------- Static part of the environment -----------
+ -- Static in the sense of lexically scoped,
+ -- wrt the original expression
+
seMode :: SimplifierMode,
seChkr :: SwitchChecker,
seCC :: CostCentreStack, -- The enclosing CCS (when profiling)
+ -- The current substitution
+ seTvSubst :: TvSubstEnv, -- InTyVar |--> OutType
+ seIdSubst :: SimplIdSubst, -- InId |--> OutExpr
+
+ ----------- Dynamic part of the environment -----------
+ -- Dynamic in the sense of describing the setup where
+ -- the expression finally ends up
+
-- The current set of in-scope variables
-- They are all OutVars, and all bound in this module
seInScope :: InScopeSet, -- OutVars only
-- Includes all variables bound by seFloats
- seFloats :: Floats,
+ seFloats :: Floats
-- See Note [Simplifier floats]
-
- -- The current substitution
- seTvSubst :: TvSubstEnv, -- InTyVar |--> OutType
- seIdSubst :: SimplIdSubst -- InId |--> OutExpr
-
}
+type StaticEnv = SimplEnv -- Just the static part is relevant
+
pprSimplEnv :: SimplEnv -> SDoc
-- Used for debugging; selective
pprSimplEnv env
= vcat [ptext (sLit "TvSubst:") <+> ppr (seTvSubst env),
- ptext (sLit "IdSubst:") <+> ppr (seIdSubst env) ]
+ ptext (sLit "IdSubst:") <+> ppr (seIdSubst env),
+ ptext (sLit "InScope:") <+> vcat (map ppr_one in_scope_vars)
+ ]
+ where
+ in_scope_vars = varEnvElts (getInScopeVars (seInScope env))
+ ppr_one v | isId v = ppr v <+> ppr (idUnfolding v)
+ | otherwise = ppr v
type SimplIdSubst = IdEnv SimplSR -- IdId |--> OutExpr
-- See Note [Extending the Subst] in CoreSubst
-- keep uniq _ = uniq `elemUFM_Directly` fvs
\end{code}
-
+Note [SimplEnv invariants]
+~~~~~~~~~~~~~~~~~~~~~~~~~~
seInScope:
The in-scope part of Subst includes *all* in-scope TyVars and Ids
The elements of the set may have better IdInfo than the
* substId adds a binding (DoneId new_id) to the substitution if
the Id's unique has changed
-
Note, though that the substitution isn't necessarily extended
- if the type changes. Why not? Because of the next point:
+ if the type of the Id changes. Why not? Because of the next point:
* We *always, always* finish by looking up in the in-scope set
any variable that doesn't get a DoneEx or DoneVar hit in the substitution.
\begin{code}
-mkSimplEnv :: SimplifierMode -> SwitchChecker -> SimplEnv
-mkSimplEnv mode switches
+mkSimplEnv :: SwitchChecker -> SimplifierMode -> SimplEnv
+mkSimplEnv switches mode
= SimplEnv { seChkr = switches, seCC = subsumedCCS,
seMode = mode, seInScope = emptyInScopeSet,
seFloats = emptyFloats,
setMode :: SimplifierMode -> SimplEnv -> SimplEnv
setMode mode env = env { seMode = mode }
+updMode :: (SimplifierMode -> SimplifierMode) -> SimplEnv -> SimplEnv
+updMode upd env = env { seMode = upd (seMode env) }
+
+inGentleMode :: SimplEnv -> Bool
+inGentleMode env = case seMode env of
+ SimplGently {} -> True
+ _other -> False
+
---------------------
getEnclosingCC :: SimplEnv -> CostCentreStack
getEnclosingCC env = seCC env
doFloatFromRhs lvl rec str rhs (SimplEnv {seFloats = Floats fs ff})
= not (isNilOL fs) && want_to_float && can_float
where
- want_to_float = isTopLevel lvl || exprIsCheap rhs
+ want_to_float = isTopLevel lvl || exprIsExpandable rhs
can_float = case ff of
FltLifted -> True
FltOkSpec -> isNotTopLevel lvl && isNonRec rec
-- The substitution is extended only if the variable is cloned, because
-- we *don't* need to use it to track occurrence info.
simplBinder env bndr
- | isTyVar bndr = do { let (env', tv) = substTyVarBndr env bndr
+ | isTyCoVar bndr = do { let (env', tv) = substTyVarBndr env bndr
; seqTyVar tv `seq` return (env', tv) }
| otherwise = do { let (env', id) = substIdBndr env bndr
; seqId id `seq` return (env', id) }
| isEmptySpecInfo old_rules = (env, out_id)
| otherwise = (modifyInScope env final_id, final_id)
where
- subst = mkCoreSubst env
+ subst = mkCoreSubst (text "local rules") env
old_rules = idSpecialisation in_id
new_rules = CoreSubst.substSpec subst out_id old_rules
final_id = out_id `setIdSpecialisation` new_rules
-
-------------------
-substIdType :: SimplEnv -> Id -> Id
-substIdType (SimplEnv { seInScope = in_scope, seTvSubst = tv_env}) id
- | isEmptyVarEnv tv_env || isEmptyVarSet (tyVarsOfType old_ty) = id
- | otherwise = Id.setIdType id (Type.substTy (TvSubst in_scope tv_env) old_ty)
- -- The tyVarsOfType is cheaper than it looks
- -- because we cache the free tyvars of the type
- -- in a Note in the id's type itself
- where
- old_ty = idType id
-
-------------------
-substUnfolding :: SimplEnv -> Unfolding -> Unfolding
-substUnfolding _ NoUnfolding = NoUnfolding
-substUnfolding _ (OtherCon cons) = OtherCon cons
-substUnfolding env (CompulsoryUnfolding rhs) = CompulsoryUnfolding (substExpr env rhs)
-substUnfolding env (CoreUnfolding rhs t v w g) = CoreUnfolding (substExpr env rhs) t v w g
-
-------------------
-substWorker :: SimplEnv -> WorkerInfo -> WorkerInfo
-substWorker _ NoWorker = NoWorker
-substWorker env wkr_info = CoreSubst.substWorker (mkCoreSubst env) wkr_info
\end{code}
%************************************************************************
\begin{code}
+getTvSubst :: SimplEnv -> TvSubst
+getTvSubst (SimplEnv { seInScope = in_scope, seTvSubst = tv_env })
+ = mkTvSubst in_scope tv_env
+
substTy :: SimplEnv -> Type -> Type
-substTy (SimplEnv { seInScope = in_scope, seTvSubst = tv_env }) ty
- = Type.substTy (TvSubst in_scope tv_env) ty
+substTy env ty = Type.substTy (getTvSubst env) ty
+
+substTyVar :: SimplEnv -> TyVar -> Type
+substTyVar env tv = Type.substTyVar (getTvSubst env) tv
substTyVarBndr :: SimplEnv -> TyVar -> (SimplEnv, TyVar)
-substTyVarBndr env@(SimplEnv { seInScope = in_scope, seTvSubst = tv_env }) tv
- = case Type.substTyVarBndr (TvSubst in_scope tv_env) tv of
+substTyVarBndr env tv
+ = case Type.substTyVarBndr (getTvSubst env) tv of
(TvSubst in_scope' tv_env', tv')
-> (env { seInScope = in_scope', seTvSubst = tv_env'}, tv')
-- here. I think the this will not usually result in a lot of work;
-- the substitutions are typically small, and laziness will avoid work in many cases.
-mkCoreSubst :: SimplEnv -> CoreSubst.Subst
-mkCoreSubst (SimplEnv { seInScope = in_scope, seTvSubst = tv_env, seIdSubst = id_env })
+mkCoreSubst :: SDoc -> SimplEnv -> CoreSubst.Subst
+mkCoreSubst doc (SimplEnv { seInScope = in_scope, seTvSubst = tv_env, seIdSubst = id_env })
= mk_subst tv_env id_env
where
mk_subst tv_env id_env = CoreSubst.mkSubst in_scope tv_env (mapVarEnv fiddle id_env)
fiddle (DoneEx e) = e
fiddle (DoneId v) = Var v
- fiddle (ContEx tv id e) = CoreSubst.substExpr (mk_subst tv id) e
+ fiddle (ContEx tv id e) = CoreSubst.substExpr (text "mkCoreSubst" <+> doc) (mk_subst tv id) e
+ -- Don't shortcut here
+
+------------------
+substIdType :: SimplEnv -> Id -> Id
+substIdType (SimplEnv { seInScope = in_scope, seTvSubst = tv_env}) id
+ | isEmptyVarEnv tv_env || isEmptyVarSet (tyVarsOfType old_ty) = id
+ | otherwise = Id.setIdType id (Type.substTy (TvSubst in_scope tv_env) old_ty)
+ -- The tyVarsOfType is cheaper than it looks
+ -- because we cache the free tyvars of the type
+ -- in a Note in the id's type itself
+ where
+ old_ty = idType id
+
+------------------
+substExpr :: SDoc -> SimplEnv -> CoreExpr -> CoreExpr
+substExpr doc env
+ = CoreSubst.substExpr (text "SimplEnv.substExpr1" <+> doc)
+ (mkCoreSubst (text "SimplEnv.substExpr2" <+> doc) env)
+ -- Do *not* short-cut in the case of an empty substitution
+ -- See Note [SimplEnv invariants]
-substExpr :: SimplEnv -> CoreExpr -> CoreExpr
-substExpr env expr = CoreSubst.substExpr (mkCoreSubst env) expr
+substUnfolding :: SimplEnv -> Unfolding -> Unfolding
+substUnfolding env unf = CoreSubst.substUnfolding (mkCoreSubst (text "subst-unfolding") env) unf
-- Do *not* short-cut in the case of an empty substitution
- -- See CoreSubst: Note [Extending the Subst]
+ -- See Note [SimplEnv invariants]
\end{code}
projects / ghc-hetmet.git / blobdiff