diff options
Diffstat (limited to 'compiler/GHC/Core/Opt/OccurAnal.hs')
| -rw-r--r-- | compiler/GHC/Core/Opt/OccurAnal.hs | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/compiler/GHC/Core/Opt/OccurAnal.hs b/compiler/GHC/Core/Opt/OccurAnal.hs index bf6393f292..5e59e149a9 100644 --- a/compiler/GHC/Core/Opt/OccurAnal.hs +++ b/compiler/GHC/Core/Opt/OccurAnal.hs @@ -22,7 +22,7 @@ module GHC.Core.Opt.OccurAnal ( zapLambdaBndrs ) where -import GHC.Prelude +import GHC.Prelude hiding ( head, init, last, tail ) import GHC.Core import GHC.Core.FVs @@ -59,6 +59,8 @@ import GHC.Builtin.Names( runRWKey ) import GHC.Unit.Module( Module ) import Data.List (mapAccumL, mapAccumR) +import Data.List.NonEmpty (NonEmpty (..), nonEmpty) +import qualified Data.List.NonEmpty as NE {- ************************************************************************ @@ -3129,7 +3131,7 @@ tagNonRecBinder :: TopLevelFlag -- At top level? tagNonRecBinder lvl usage binder = let occ = lookupDetails usage binder - will_be_join = decideJoinPointHood lvl usage [binder] + will_be_join = decideJoinPointHood lvl usage (NE.singleton binder) occ' | will_be_join = -- must already be marked AlwaysTailCalled assert (isAlwaysTailCalled occ) occ | otherwise = markNonTail occ @@ -3154,7 +3156,11 @@ tagRecBinders lvl body_uds details_s -- 1. Determine join-point-hood of whole group, as determined by -- the *unadjusted* usage details unadj_uds = foldr andUDs body_uds rhs_udss - will_be_joins = decideJoinPointHood lvl unadj_uds bndrs + + -- This is only used in `mb_join_arity`, to adjust each `Details` in `details_s`, thus, + -- when `bndrs` is non-empty. So, we only write `maybe False` as `decideJoinPointHood` + -- takes a `NonEmpty CoreBndr`; the default value `False` won't affect program behavior. + will_be_joins = maybe False (decideJoinPointHood lvl unadj_uds) (nonEmpty bndrs) -- 2. Adjust usage details of each RHS, taking into account the -- join-point-hood decision @@ -3210,12 +3216,12 @@ setBinderOcc occ_info bndr -- -- See Note [Invariants on join points] in "GHC.Core". decideJoinPointHood :: TopLevelFlag -> UsageDetails - -> [CoreBndr] + -> NonEmpty CoreBndr -> Bool decideJoinPointHood TopLevel _ _ = False decideJoinPointHood NotTopLevel usage bndrs - | isJoinId (head bndrs) + | isJoinId (NE.head bndrs) = warnPprTrace (not all_ok) "OccurAnal failed to rediscover join point(s)" (ppr bndrs) all_ok |