Use a Set to represent Ways

Should make `member` queries faster and avoid messing up with missing
`nubSort`.

Metric Increase:
    hie002

1 files changed, 10 insertions, 8 deletions

diff --git a/compiler/GHC.hs b/compiler/GHC.hs
index 256a414e64..11c1ce8521 100644
--- a/compiler/GHC.hs
+++ b/compiler/GHC.hs
@@ -336,6 +336,7 @@ import GHC.Driver.Finder
 import GHC.Driver.Types
 import GHC.Driver.CmdLine
 import GHC.Driver.Session hiding (WarnReason(..))
+import GHC.Driver.Ways
 import SysTools
 import SysTools.BaseDir
 import Annotations
@@ -365,6 +366,7 @@ import FileCleanup
 import Data.Foldable
 import qualified Data.Map.Strict as Map
 import Data.Set (Set)
+import qualified Data.Set as S
 import qualified Data.Sequence as Seq
 import Data.Maybe
 import Data.Time
@@ -542,10 +544,10 @@ checkBrokenTablesNextToCode dflags
 
 checkBrokenTablesNextToCode' :: MonadIO m => DynFlags -> m Bool
 checkBrokenTablesNextToCode' dflags
-  | not (isARM arch)              = return False
-  | WayDyn `notElem` ways dflags  = return False
-  | not (tablesNextToCode dflags) = return False
-  | otherwise                     = do
+  | not (isARM arch)                 = return False
+  | WayDyn `S.notMember` ways dflags = return False
+  | not (tablesNextToCode dflags)    = return False
+  | otherwise                        = do
     linkerInfo <- liftIO $ getLinkerInfo dflags
     case linkerInfo of
       GnuLD _  -> return True
@@ -605,9 +607,9 @@ setSessionDynFlags dflags = do
          let
            prog = pgm_i dflags ++ flavour
            flavour
-             | WayProf `elem` ways dflags = "-prof"
-             | WayDyn `elem` ways dflags  = "-dyn"
-             | otherwise                  = ""
+             | WayProf `S.member` ways dflags = "-prof"
+             | WayDyn `S.member` ways dflags  = "-dyn"
+             | otherwise                      = ""
            msg = text "Starting " <> text prog
          tr <- if verbosity dflags >= 3
                 then return (logInfo dflags (defaultDumpStyle dflags) msg)
@@ -617,7 +619,7 @@ setSessionDynFlags dflags = do
             { iservConfProgram  = prog
             , iservConfOpts     = getOpts dflags opt_i
             , iservConfProfiled = gopt Opt_SccProfilingOn dflags
-            , iservConfDynamic  = WayDyn `elem` ways dflags
+            , iservConfDynamic  = WayDyn `S.member` ways dflags
             , iservConfHook     = createIservProcessHook (hooks dflags)
             , iservConfTrace    = tr
             }