expr_ty = exprType expr
bindingOk :: TopLevelFlag -> CoreExpr -> Type -> Bool
--- True iff we can have a binding of this expression at this leve
+-- True iff we can have a binding of this expression at this level
-- Precondition: the type is the type of the expression
bindingOk top_lvl _ expr_ty
| isTopLevel top_lvl = not (isUnLiftedType expr_ty)
-> OccInfo -> OutExpr
-> Unfolding -> SimplM Unfolding
-- Note [Setting the new unfolding]
-simplUnfolding env _ _ _ _ (DFunUnfolding con ops)
- = return (DFunUnfolding con ops')
+simplUnfolding env _ _ _ _ (DFunUnfolding ar con ops)
+ = return (DFunUnfolding ar con ops')
where
ops' = map (substExpr (text "simplUnfolding") env) ops
but that is bad if 'c' is *not* later scrutinised.
So instead we do both: we pass 'c' and 'c#' , and record in c's inlining
-that it's really I# c#, thus
+(an InlineRule) that it's really I# c#, thus
$j = \c# -> \c[=I# c#] -> ...c....
Absence analysis may later discard 'c'.
+NB: take great care when doing strictness analysis;
+ see Note [Lamba-bound unfoldings] in DmdAnal.
+
+Also note that we can still end up passing stuff that isn't used. Before
+strictness analysis we have
+ let $j x y c{=(x,y)} = (h c, ...)
+ in ...
+After strictness analysis we see that h is strict, we end up with
+ let $j x y c{=(x,y)} = ($wh x y, ...)
+and c is unused.
Note [Duplicated env]
~~~~~~~~~~~~~~~~~~~~~