diff options
Diffstat (limited to 'compiler/GHC/Core/Opt/OccurAnal.hs')
| -rw-r--r-- | compiler/GHC/Core/Opt/OccurAnal.hs | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/compiler/GHC/Core/Opt/OccurAnal.hs b/compiler/GHC/Core/Opt/OccurAnal.hs index c4f714eef1..1312b33387 100644 --- a/compiler/GHC/Core/Opt/OccurAnal.hs +++ b/compiler/GHC/Core/Opt/OccurAnal.hs @@ -39,6 +39,7 @@ import GHC.Types.Demand ( argOneShots, argsOneShots ) import GHC.Data.Graph.Directed ( SCC(..), Node(..) , stronglyConnCompFromEdgedVerticesUniq , stronglyConnCompFromEdgedVerticesUniqR ) +import GHC.Builtin.Names( runRWKey ) import GHC.Types.Unique import GHC.Types.Unique.FM import GHC.Types.Unique.Set @@ -1882,8 +1883,15 @@ occAnalApp :: OccEnv -> (UsageDetails, Expr CoreBndr) -- Naked variables (not applied) end up here too occAnalApp env (Var fun, args, ticks) - | null ticks = (all_uds, mkApps fun' args') - | otherwise = (all_uds, mkTicks ticks $ mkApps fun' args') + -- Account for join arity of runRW# continuation + -- See Note [Simplification of runRW#] + | fun `hasKey` runRWKey + , [t1, t2, arg] <- args + , let (usage, arg') = occAnalRhs env (Just 1) arg + = (usage, mkTicks ticks $ mkApps (Var fun) [t1, t2, arg']) + + | otherwise + = (all_uds, mkTicks ticks $ mkApps fun' args') where (fun', fun_id') = lookupVarEnv (occ_bs_env env) fun `orElse` (Var fun, fun) |