diff options
| -rw-r--r-- | compiler/basicTypes/Demand.hs | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/compiler/basicTypes/Demand.hs b/compiler/basicTypes/Demand.hs index 07fb39a38f..3ee02f109d 100644 --- a/compiler/basicTypes/Demand.hs +++ b/compiler/basicTypes/Demand.hs @@ -389,9 +389,12 @@ mkUCall :: Count -> UseDmd -> UseDmd mkUCall c a = UCall c a mkUData :: [[ArgUse]] -> UseDmd -mkUData ux - | all (all (== Abs)) ux = UHead - | otherwise = UData ux +mkUData [ux] | all (== Abs) ux = UHead + -- Sum types are not UHead (which is assumed to be the demand type of a seq), + -- As although the components may possibly not be used, the information _which_ + -- constructor is used is important. +mkUData uss | all null uss = Used +mkUData uss = UData uss lubCount :: Count -> Count -> Count lubCount _ Many = Many |