-- 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.
-- in-scope set (although it might also have been created with newId)
-- but it may now have more IdInfo
addNonRec env id rhs
- = env { seFloats = seFloats env `addFlts` unitFloat (NonRec id rhs),
+ = id `seq` -- This seq forces the Id, and hence its IdInfo,
+ -- and hence any inner substitutions
+ env { seFloats = seFloats env `addFlts` unitFloat (NonRec id rhs),
seInScope = extendInScopeSet (seInScope env) id }
extendFloats :: SimplEnv -> OutBind -> SimplEnv
-- 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) }
------------------
substExpr :: SDoc -> SimplEnv -> CoreExpr -> CoreExpr
substExpr doc env
- = CoreSubst.substExprSC (text "SimplEnv.substExpr1" <+> doc)
- (mkCoreSubst (text "SimplEnv.substExpr2" <+> 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 CoreSubst: Note [Extending the Subst]
+ -- See Note [SimplEnv invariants]
substUnfolding :: SimplEnv -> Unfolding -> Unfolding
-substUnfolding env unf = CoreSubst.substUnfoldingSC (mkCoreSubst (text "subst-unfolding") env) unf
+substUnfolding env unf = CoreSubst.substUnfolding (mkCoreSubst (text "subst-unfolding") env) unf
+ -- Do *not* short-cut in the case of an empty substitution
+ -- See Note [SimplEnv invariants]
\end{code}