\begin{code}
manifestArity :: CoreExpr -> Arity
-- ^ manifestArity sees how many leading value lambdas there are
-manifestArity (Lam v e) | isId v = 1 + manifestArity e
- | otherwise = manifestArity e
-manifestArity (Note _ e) = manifestArity e
-manifestArity (Cast e _) = manifestArity e
-manifestArity _ = 0
+manifestArity (Lam v e) | isId v = 1 + manifestArity e
+ | otherwise = manifestArity e
+manifestArity (Note n e) | notSccNote n = manifestArity e
+manifestArity (Cast e _) = manifestArity e
+manifestArity _ = 0
exprArity :: CoreExpr -> Arity
-- ^ An approximate, fast, version of 'exprEtaExpandArity'
go (Var v) = idArity v
go (Lam x e) | isId x = go e + 1
| otherwise = go e
- go (Note _ e) = go e
+ go (Note n e) | notSccNote n = go e
go (Cast e co) = go e `min` length (typeArity (snd (coercionKind co)))
-- Note [exprArity invariant]
go (App e (Type _)) = go e
-- See Note [Dictionary-like types] in TcType.lhs for why we use
-- isDictLikeTy here rather than isDictTy
-arityType dicts_cheap (Note _ e) = arityType dicts_cheap e
+arityType dicts_cheap (Note n e)
+ | notSccNote n = arityType dicts_cheap e
arityType dicts_cheap (Cast e _) = arityType dicts_cheap e
arityType _ _ = vanillaArityType
\end{code}