diff options
| -rw-r--r-- | compiler/GHC/Iface/Type.hs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/GHC/Iface/Type.hs b/compiler/GHC/Iface/Type.hs index 57c31920b4..73ce53e34d 100644 --- a/compiler/GHC/Iface/Type.hs +++ b/compiler/GHC/Iface/Type.hs @@ -176,6 +176,11 @@ data IfaceType PromotionFlag -- A bit like IfaceTyCon IfaceAppArgs -- arity = length args -- For promoted data cons, the kind args are omitted + -- Why have this? Only for efficiency: IfaceTupleTy can omit the + -- type arguments, as they can be recreated when deserializing. + -- In an experiment, removing IfaceTupleTy resulted in a 0.75% regression + -- in interface file size (in GHC's boot libraries). + -- See !3987. type IfaceMult = IfaceType |