diff options
Diffstat (limited to 'compiler/GHC/Core/Opt/Arity.hs')
| -rw-r--r-- | compiler/GHC/Core/Opt/Arity.hs | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/compiler/GHC/Core/Opt/Arity.hs b/compiler/GHC/Core/Opt/Arity.hs index fbbcf1c2ad..832fba354c 100644 --- a/compiler/GHC/Core/Opt/Arity.hs +++ b/compiler/GHC/Core/Opt/Arity.hs @@ -3103,9 +3103,13 @@ etaBodyForJoinPoint need_args body | Just (tv, res_ty) <- splitForAllTyCoVar_maybe ty , let (subst', tv') = substVarBndr subst tv = go (n-1) res_ty subst' (tv' : rev_bs) (e `App` varToCoreExpr tv') + -- The varToCoreExpr is important: `tv` might be a coercion variable + | Just (_, mult, arg_ty, res_ty) <- splitFunTy_maybe ty , let (subst', b) = freshEtaId n subst (Scaled mult arg_ty) - = go (n-1) res_ty subst' (b : rev_bs) (e `App` Var b) + = go (n-1) res_ty subst' (b : rev_bs) (e `App` varToCoreExpr b) + -- The varToCoreExpr is important: `b` might be a coercion variable + | otherwise = pprPanic "etaBodyForJoinPoint" $ int need_args $$ ppr body $$ ppr (exprType body) |