    {-# LANGUAGE PatternSynonyms #-}
    {-
    (c) The AQUA Project, Glasgow University, 1993-1998

    \section[GHC.Core.Opt.Simplify.Monad]{The simplifier Monad}
    -}

    module GHC.Core.Opt.Simplify.Monad (
            -- The monad
            TopEnvConfig(..), SimplM,
            initSmpl, traceSmpl,
            getSimplRules,

            -- Unique supply
            MonadUnique(..), newId, newJoinId,

            -- Counting
            SimplCount, tick, freeTick, checkedTick,
            getSimplCount, zeroSimplCount, pprSimplCount,
            plusSimplCount, isZeroSimplCount
        ) where

    import GHC.Prelude

    import GHC.Types.Var       ( Var, isId, mkLocalVar )
    import GHC.Types.Name      ( mkSystemVarName )
    import GHC.Types.Id        ( Id, mkSysLocalOrCoVarM )
    import GHC.Types.Id.Info   ( IdDetails(..), vanillaIdInfo, setArityInfo )
    import GHC.Core.Type       ( Type, Mult )
    import GHC.Core.Opt.Stats
    import GHC.Core.Rules
    import GHC.Core.Utils      ( mkLamTypes )
    import GHC.Types.Unique.Supply
    import GHC.Driver.Flags
    import GHC.Utils.Outputable
    import GHC.Data.FastString
    import GHC.Utils.Monad
    import GHC.Utils.Logger as Logger
    import GHC.Utils.Misc      ( count )
    import GHC.Utils.Panic     (throwGhcExceptionIO, GhcException (..))
    import GHC.Types.Basic     ( IntWithInf, treatZeroAsInf, mkIntWithInf )
    import Control.Monad       ( ap )
    import GHC.Core.Multiplicity        ( pattern ManyTy )
    import GHC.Exts( oneShot )

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Monad plumbing}
    *                                                                      *
    ************************************************************************
    -}

    newtype SimplM result
      =  SM'  { forall result.
    SimplM result
    -> SimplTopEnv -> SimplCount -> IO (result, SimplCount)
    unSM :: SimplTopEnv
                     -> SimplCount
                     -> IO (result, SimplCount)}
        -- We only need IO here for dump output, but since we already have it
        -- we might as well use it for uniques.

    pattern SM :: (SimplTopEnv -> SimplCount
                   -> IO (result, SimplCount))
              -> SimplM result
    -- This pattern synonym makes the simplifier monad eta-expand,
    -- which as a very beneficial effect on compiler performance
    -- (worth a 1-2% reduction in bytes-allocated).  See #18202.
    -- See Note [The one-shot state monad trick] in GHC.Utils.Monad
    pattern $mSM :: forall {r} {result}.
    SimplM result
    -> ((SimplTopEnv -> SimplCount -> IO (result, SimplCount)) -> r)
    -> ((# #) -> r)
    -> r
    $bSM :: forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM m <- SM' m
      where
        SM SimplTopEnv -> SimplCount -> IO (result, SimplCount)
    m = (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM' ((SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplTopEnv -> SimplCount -> IO (result, SimplCount)
    forall a b. (a -> b) -> a -> b
    oneShot ((SimplTopEnv -> SimplCount -> IO (result, SimplCount))
     -> SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplTopEnv
    -> SimplCount
    -> IO (result, SimplCount)
    forall a b. (a -> b) -> a -> b
    $ \SimplTopEnv
    env -> (SimplCount -> IO (result, SimplCount))
    -> SimplCount -> IO (result, SimplCount)
    forall a b. (a -> b) -> a -> b
    oneShot ((SimplCount -> IO (result, SimplCount))
     -> SimplCount -> IO (result, SimplCount))
    -> (SimplCount -> IO (result, SimplCount))
    -> SimplCount
    -> IO (result, SimplCount)
    forall a b. (a -> b) -> a -> b
    $ \SimplCount
    ct -> SimplTopEnv -> SimplCount -> IO (result, SimplCount)
    m SimplTopEnv
    env SimplCount
    ct)

    -- See Note [The environments of the Simplify pass]
    data TopEnvConfig = TopEnvConfig
      { TopEnvConfig -> Int
    te_history_size :: !Int
      , TopEnvConfig -> Int
    te_tick_factor :: !Int
      }

    data SimplTopEnv
      = STE { -- See Note [The environments of the Simplify pass]
              SimplTopEnv -> TopEnvConfig
    st_config :: !TopEnvConfig
            , SimplTopEnv -> Logger
    st_logger    :: !Logger
            , SimplTopEnv -> IntWithInf
    st_max_ticks :: !IntWithInf  -- ^ Max #ticks in this simplifier run
            , SimplTopEnv -> IO RuleEnv
    st_read_ruleenv :: !(IO RuleEnv)
              -- ^ The action to retrieve an up-to-date EPS RuleEnv
              -- See Note [Overall plumbing for rules]
            }

    initSmpl :: Logger
             -> IO RuleEnv
             -> TopEnvConfig
             -> Int -- ^ Size of the bindings, used to limit the number of ticks we allow
             -> SimplM a
             -> IO (a, SimplCount)

    initSmpl :: forall a.
    Logger
    -> IO RuleEnv
    -> TopEnvConfig
    -> Int
    -> SimplM a
    -> IO (a, SimplCount)
    initSmpl Logger
    logger IO RuleEnv
    read_ruleenv TopEnvConfig
    cfg Int
    size SimplM a
    m
      = do -- No init count; set to 0
           let simplCount :: SimplCount
    simplCount = Bool -> SimplCount
    zeroSimplCount (Bool -> SimplCount) -> Bool -> SimplCount
    forall a b. (a -> b) -> a -> b
    $ Logger -> DumpFlag -> Bool
    logHasDumpFlag Logger
    logger DumpFlag
    Opt_D_dump_simpl_stats
           SimplM a -> SimplTopEnv -> SimplCount -> IO (a, SimplCount)
    forall result.
    SimplM result
    -> SimplTopEnv -> SimplCount -> IO (result, SimplCount)
    unSM SimplM a
    m SimplTopEnv
    env SimplCount
    simplCount
      where
        env :: SimplTopEnv
    env = STE { st_config :: TopEnvConfig
    st_config = TopEnvConfig
    cfg
                  , st_logger :: Logger
    st_logger = Logger
    logger
                  , st_max_ticks :: IntWithInf
    st_max_ticks = TopEnvConfig -> Int -> IntWithInf
    computeMaxTicks TopEnvConfig
    cfg Int
    size
                  , st_read_ruleenv :: IO RuleEnv
    st_read_ruleenv = IO RuleEnv
    read_ruleenv
                  }

    computeMaxTicks :: TopEnvConfig -> Int -> IntWithInf
    -- Compute the max simplifier ticks as
    --     (base-size + pgm-size) * magic-multiplier * tick-factor/100
    -- where
    --    magic-multiplier is a constant that gives reasonable results
    --    base-size is a constant to deal with size-zero programs
    computeMaxTicks :: TopEnvConfig -> Int -> IntWithInf
    computeMaxTicks TopEnvConfig
    cfg Int
    size
      = Int -> IntWithInf
    treatZeroAsInf (Int -> IntWithInf) -> Int -> IntWithInf
    forall a b. (a -> b) -> a -> b
    $
        Integer -> Int
    forall a. Num a => Integer -> a
    fromInteger ((Int -> Integer
    forall a. Integral a => a -> Integer
    toInteger (Int
    size Int -> Int -> Int
    forall a. Num a => a -> a -> a
    + Int
    base_size)
                      Integer -> Integer -> Integer
    forall a. Num a => a -> a -> a
    * Int -> Integer
    forall a. Integral a => a -> Integer
    toInteger (Int
    tick_factor Int -> Int -> Int
    forall a. Num a => a -> a -> a
    * Int
    magic_multiplier))
              Integer -> Integer -> Integer
    forall a. Integral a => a -> a -> a
    `div` Integer
    100)
      where
        tick_factor :: Int
    tick_factor      = TopEnvConfig -> Int
    te_tick_factor TopEnvConfig
    cfg
        base_size :: Int
    base_size        = Int
    100
        magic_multiplier :: Int
    magic_multiplier = Int
    40
            -- MAGIC NUMBER, multiplies the simplTickFactor
            -- We can afford to be generous; this is really
            -- just checking for loops, and shouldn't usually fire
            -- A figure of 20 was too small: see #5539.

    {-# INLINE thenSmpl #-}
    {-# INLINE thenSmpl_ #-}
    {-# INLINE returnSmpl #-}
    {-# INLINE mapSmpl #-}

    instance Functor SimplM where
      fmap :: forall a b. (a -> b) -> SimplM a -> SimplM b
    fmap = (a -> b) -> SimplM a -> SimplM b
    forall a b. (a -> b) -> SimplM a -> SimplM b
    mapSmpl

    instance Applicative SimplM where
        pure :: forall a. a -> SimplM a
    pure  = a -> SimplM a
    forall a. a -> SimplM a
    returnSmpl
        <*> :: forall a b. SimplM (a -> b) -> SimplM a -> SimplM b
    (<*>) = SimplM (a -> b) -> SimplM a -> SimplM b
    forall (m :: * -> *) a b. Monad m => m (a -> b) -> m a -> m b
    ap
        *> :: forall a b. SimplM a -> SimplM b -> SimplM b
    (*>)  = SimplM a -> SimplM b -> SimplM b
    forall a b. SimplM a -> SimplM b -> SimplM b
    thenSmpl_

    instance Monad SimplM where
       >> :: forall a b. SimplM a -> SimplM b -> SimplM b
    (>>)   = SimplM a -> SimplM b -> SimplM b
    forall a b. SimplM a -> SimplM b -> SimplM b
    forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
    (*>)
       >>= :: forall a b. SimplM a -> (a -> SimplM b) -> SimplM b
    (>>=)  = SimplM a -> (a -> SimplM b) -> SimplM b
    forall a b. SimplM a -> (a -> SimplM b) -> SimplM b
    thenSmpl

    mapSmpl :: (a -> b) -> SimplM a -> SimplM b
    mapSmpl :: forall a b. (a -> b) -> SimplM a -> SimplM b
    mapSmpl a -> b
    f SimplM a
    m = SimplM a -> (a -> SimplM b) -> SimplM b
    forall a b. SimplM a -> (a -> SimplM b) -> SimplM b
    thenSmpl SimplM a
    m (b -> SimplM b
    forall a. a -> SimplM a
    returnSmpl (b -> SimplM b) -> (a -> b) -> a -> SimplM b
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . a -> b
    f)

    returnSmpl :: a -> SimplM a
    returnSmpl :: forall a. a -> SimplM a
    returnSmpl a
    e = (SimplTopEnv -> SimplCount -> IO (a, SimplCount)) -> SimplM a
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM (\SimplTopEnv
    _st_env SimplCount
    sc -> (a, SimplCount) -> IO (a, SimplCount)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (a
    e, SimplCount
    sc))

    thenSmpl  :: SimplM a -> (a -> SimplM b) -> SimplM b
    thenSmpl_ :: SimplM a -> SimplM b -> SimplM b

    thenSmpl :: forall a b. SimplM a -> (a -> SimplM b) -> SimplM b
    thenSmpl SimplM a
    m a -> SimplM b
    k
      = (SimplTopEnv -> SimplCount -> IO (b, SimplCount)) -> SimplM b
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM ((SimplTopEnv -> SimplCount -> IO (b, SimplCount)) -> SimplM b)
    -> (SimplTopEnv -> SimplCount -> IO (b, SimplCount)) -> SimplM b
    forall a b. (a -> b) -> a -> b
    $ \SimplTopEnv
    st_env SimplCount
    sc0 -> do
          (m_result, sc1) <- SimplM a -> SimplTopEnv -> SimplCount -> IO (a, SimplCount)
    forall result.
    SimplM result
    -> SimplTopEnv -> SimplCount -> IO (result, SimplCount)
    unSM SimplM a
    m SimplTopEnv
    st_env SimplCount
    sc0
          unSM (k m_result) st_env sc1

    thenSmpl_ :: forall a b. SimplM a -> SimplM b -> SimplM b
    thenSmpl_ SimplM a
    m SimplM b
    k
      = (SimplTopEnv -> SimplCount -> IO (b, SimplCount)) -> SimplM b
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM ((SimplTopEnv -> SimplCount -> IO (b, SimplCount)) -> SimplM b)
    -> (SimplTopEnv -> SimplCount -> IO (b, SimplCount)) -> SimplM b
    forall a b. (a -> b) -> a -> b
    $ \SimplTopEnv
    st_env SimplCount
    sc0 -> do
          (_, sc1) <- SimplM a -> SimplTopEnv -> SimplCount -> IO (a, SimplCount)
    forall result.
    SimplM result
    -> SimplTopEnv -> SimplCount -> IO (result, SimplCount)
    unSM SimplM a
    m SimplTopEnv
    st_env SimplCount
    sc0
          unSM k st_env sc1

    -- TODO: this specializing is not allowed
    -- {-# SPECIALIZE mapM         :: (a -> SimplM b) -> [a] -> SimplM [b] #-}
    -- {-# SPECIALIZE mapAndUnzipM :: (a -> SimplM (b, c)) -> [a] -> SimplM ([b],[c]) #-}
    -- {-# SPECIALIZE mapAccumLM   :: (acc -> b -> SimplM (acc,c)) -> acc -> [b] -> SimplM (acc, [c]) #-}

    traceSmpl :: String -> SDoc -> SimplM ()
    traceSmpl :: String -> SDoc -> SimplM ()
    traceSmpl String
    herald SDoc
    doc
      = do logger <- SimplM Logger
    forall (m :: * -> *). HasLogger m => m Logger
    getLogger
           liftIO $ Logger.putDumpFileMaybe logger Opt_D_dump_simpl_trace "Simpl Trace"
             FormatText
             (hang (text herald) 2 doc)
    {-# INLINE traceSmpl #-}  -- see Note [INLINE conditional tracing utilities]

    {-
    ************************************************************************
    *                                                                      *
    \subsection{The unique supply}
    *                                                                      *
    ************************************************************************
    -}

    -- See Note [Uniques for wired-in prelude things and known tags] in GHC.Builtin.Uniques
    simplTag :: Char
    simplTag :: Char
    simplTag = Char
    's'

    instance MonadUnique SimplM where
        getUniqueSupplyM :: SimplM UniqSupply
    getUniqueSupplyM = IO UniqSupply -> SimplM UniqSupply
    forall a. IO a -> SimplM a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO UniqSupply -> SimplM UniqSupply)
    -> IO UniqSupply -> SimplM UniqSupply
    forall a b. (a -> b) -> a -> b
    $ Char -> IO UniqSupply
    mkSplitUniqSupply Char
    simplTag
        getUniqueM :: SimplM Unique
    getUniqueM = IO Unique -> SimplM Unique
    forall a. IO a -> SimplM a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO Unique -> SimplM Unique) -> IO Unique -> SimplM Unique
    forall a b. (a -> b) -> a -> b
    $ Char -> IO Unique
    uniqFromTag Char
    simplTag

    instance HasLogger SimplM where
        getLogger :: SimplM Logger
    getLogger = (SimplTopEnv -> Logger) -> SimplM Logger
    forall a. (SimplTopEnv -> a) -> SimplM a
    gets SimplTopEnv -> Logger
    st_logger

    instance MonadIO SimplM where
        liftIO :: forall a. IO a -> SimplM a
    liftIO = (SimplTopEnv -> IO a) -> SimplM a
    forall a. (SimplTopEnv -> IO a) -> SimplM a
    liftIOWithEnv ((SimplTopEnv -> IO a) -> SimplM a)
    -> (IO a -> SimplTopEnv -> IO a) -> IO a -> SimplM a
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . IO a -> SimplTopEnv -> IO a
    forall a b. a -> b -> a
    const

    getSimplRules :: SimplM RuleEnv
    getSimplRules :: SimplM RuleEnv
    getSimplRules = (SimplTopEnv -> IO RuleEnv) -> SimplM RuleEnv
    forall a. (SimplTopEnv -> IO a) -> SimplM a
    liftIOWithEnv SimplTopEnv -> IO RuleEnv
    st_read_ruleenv

    liftIOWithEnv :: (SimplTopEnv -> IO a) -> SimplM a
    liftIOWithEnv :: forall a. (SimplTopEnv -> IO a) -> SimplM a
    liftIOWithEnv SimplTopEnv -> IO a
    m = (SimplTopEnv -> SimplCount -> IO (a, SimplCount)) -> SimplM a
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM (\SimplTopEnv
    st_env SimplCount
    sc -> do
        x <- SimplTopEnv -> IO a
    m SimplTopEnv
    st_env
        return (x, sc))

    gets :: (SimplTopEnv -> a) -> SimplM a
    gets :: forall a. (SimplTopEnv -> a) -> SimplM a
    gets SimplTopEnv -> a
    f = (SimplTopEnv -> IO a) -> SimplM a
    forall a. (SimplTopEnv -> IO a) -> SimplM a
    liftIOWithEnv (a -> IO a
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (a -> IO a) -> (SimplTopEnv -> a) -> SimplTopEnv -> IO a
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . SimplTopEnv -> a
    f)

    newId :: FastString -> Mult -> Type -> SimplM Id
    newId :: FastString -> Mult -> Mult -> SimplM Id
    newId FastString
    fs Mult
    w Mult
    ty = FastString -> Mult -> Mult -> SimplM Id
    forall (m :: * -> *).
    MonadUnique m =>
    FastString -> Mult -> Mult -> m Id
    mkSysLocalOrCoVarM FastString
    fs Mult
    w Mult
    ty

    -- | Make a join id with given type and arity but without call-by-value annotations.
    newJoinId :: [Var] -> Type -> SimplM Id
    newJoinId :: [Id] -> Mult -> SimplM Id
    newJoinId [Id]
    bndrs Mult
    body_ty
      = do { uniq <- SimplM Unique
    forall (m :: * -> *). MonadUnique m => m Unique
    getUniqueM
           ; let name       = Unique -> FastString -> Name
    mkSystemVarName Unique
    uniq (String -> FastString
    fsLit String
    "$j")
                 join_id_ty = [Id] -> Mult -> Mult
    mkLamTypes [Id]
    bndrs Mult
    body_ty  -- Note [Funky mkLamTypes]
                 arity      = (Id -> Bool) -> [Id] -> Int
    forall a. (a -> Bool) -> [a] -> Int
    count Id -> Bool
    isId [Id]
    bndrs
                 -- arity: See Note [Invariants on join points] invariant 2b, in GHC.Core
                 join_arity = [Id] -> Int
    forall a. [a] -> Int
    forall (t :: * -> *) a. Foldable t => t a -> Int
    length [Id]
    bndrs
                 details    = Int -> Maybe [CbvMark] -> IdDetails
    JoinId Int
    join_arity Maybe [CbvMark]
    forall a. Maybe a
    Nothing
                 id_info    = IdInfo
    vanillaIdInfo IdInfo -> Int -> IdInfo
    `setArityInfo` Int
    arity

           ; return (mkLocalVar details name ManyTy join_id_ty id_info) }

    {-
    ************************************************************************
    *                                                                      *
    \subsection{Counting up what we've done}
    *                                                                      *
    ************************************************************************
    -}

    getSimplCount :: SimplM SimplCount
    getSimplCount :: SimplM SimplCount
    getSimplCount = (SimplTopEnv -> SimplCount -> IO (SimplCount, SimplCount))
    -> SimplM SimplCount
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM (\SimplTopEnv
    _st_env SimplCount
    sc -> (SimplCount, SimplCount) -> IO (SimplCount, SimplCount)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return (SimplCount
    sc, SimplCount
    sc))

    tick :: Tick -> SimplM ()
    tick :: Tick -> SimplM ()
    tick Tick
    t = (SimplTopEnv -> SimplCount -> IO ((), SimplCount)) -> SimplM ()
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM (\SimplTopEnv
    st_env SimplCount
    sc -> let
      history_size :: Int
    history_size = TopEnvConfig -> Int
    te_history_size (SimplTopEnv -> TopEnvConfig
    st_config SimplTopEnv
    st_env)
      sc' :: SimplCount
    sc' = Int -> Tick -> SimplCount -> SimplCount
    doSimplTick Int
    history_size Tick
    t SimplCount
    sc
      in SimplCount
    sc' SimplCount -> IO ((), SimplCount) -> IO ((), SimplCount)
    forall a b. a -> b -> b
    `seq` ((), SimplCount) -> IO ((), SimplCount)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ((), SimplCount
    sc'))

    checkedTick :: Tick -> SimplM ()
    -- Try to take a tick, but fail if too many
    checkedTick :: Tick -> SimplM ()
    checkedTick Tick
    t
      = (SimplTopEnv -> SimplCount -> IO ((), SimplCount)) -> SimplM ()
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM (\SimplTopEnv
    st_env SimplCount
    sc ->
               if SimplTopEnv -> IntWithInf
    st_max_ticks SimplTopEnv
    st_env IntWithInf -> IntWithInf -> Bool
    forall a. Ord a => a -> a -> Bool
    <= Int -> IntWithInf
    mkIntWithInf (SimplCount -> Int
    simplCountN SimplCount
    sc)
               then GhcException -> IO ((), SimplCount)
    forall a. GhcException -> IO a
    throwGhcExceptionIO (GhcException -> IO ((), SimplCount))
    -> GhcException -> IO ((), SimplCount)
    forall a b. (a -> b) -> a -> b
    $
                      String -> SDoc -> GhcException
    PprProgramError String
    "Simplifier ticks exhausted" (SimplCount -> SDoc
    msg SimplCount
    sc)
               else let
                 history_size :: Int
    history_size = TopEnvConfig -> Int
    te_history_size (SimplTopEnv -> TopEnvConfig
    st_config SimplTopEnv
    st_env)
                 sc' :: SimplCount
    sc' = Int -> Tick -> SimplCount -> SimplCount
    doSimplTick Int
    history_size Tick
    t SimplCount
    sc
                 in SimplCount
    sc' SimplCount -> IO ((), SimplCount) -> IO ((), SimplCount)
    forall a b. a -> b -> b
    `seq` ((), SimplCount) -> IO ((), SimplCount)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ((), SimplCount
    sc'))
      where
        msg :: SimplCount -> SDoc
    msg SimplCount
    sc = [SDoc] -> SDoc
    forall doc. IsDoc doc => [doc] -> doc
    vcat
          [ String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "When trying" SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> Tick -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Tick
    t
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "To increase the limit, use -fsimpl-tick-factor=N (default 100)."
          , SDoc
    forall doc. IsLine doc => doc
    space
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "In addition try adjusting -funfolding-case-threshold=N and"
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "-funfolding-case-scaling=N for the module in question."
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "Using threshold=1 and scaling=5 should break most inlining loops."
          , SDoc
    forall doc. IsLine doc => doc
    space
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "If you need to increase the tick factor substantially, while also"
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "adjusting unfolding parameters please file a bug report and"
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "indicate the factor you needed."
          , SDoc
    forall doc. IsLine doc => doc
    space
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "If GHC was unable to complete compilation even"
                   SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "with a very large factor"
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "(a thousand or more), please consult the"
                    SDoc -> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc -> doc
    <+> SDoc -> SDoc
    forall doc. IsLine doc => doc -> doc
    doubleQuotes (String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "Known bugs or infelicities")
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "section in the Users Guide before filing a report. There are a"
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "few situations unlikely to occur in practical programs for which"
          , String -> SDoc
    forall doc. IsLine doc => String -> doc
    text String
    "simplifier non-termination has been judged acceptable."
          , SDoc
    forall doc. IsLine doc => doc
    space
          , SimplCount -> SDoc
    forall {doc}. IsLine doc => SimplCount -> doc
    pp_details SimplCount
    sc
          , SimplCount -> SDoc
    pprSimplCount SimplCount
    sc ]
        pp_details :: SimplCount -> doc
    pp_details SimplCount
    sc
          | SimplCount -> Bool
    hasDetailedCounts SimplCount
    sc = doc
    forall doc. IsOutput doc => doc
    empty
          | Bool
    otherwise = String -> doc
    forall doc. IsLine doc => String -> doc
    text String
    "To see detailed counts use -ddump-simpl-stats"

    freeTick :: Tick -> SimplM ()
    -- Record a tick, but don't add to the total tick count, which is
    -- used to decide when nothing further has happened
    freeTick :: Tick -> SimplM ()
    freeTick Tick
    t
       = (SimplTopEnv -> SimplCount -> IO ((), SimplCount)) -> SimplM ()
    forall result.
    (SimplTopEnv -> SimplCount -> IO (result, SimplCount))
    -> SimplM result
    SM (\SimplTopEnv
    _st_env SimplCount
    sc -> let sc' :: SimplCount
    sc' = Tick -> SimplCount -> SimplCount
    doFreeSimplTick Tick
    t SimplCount
    sc
                               in SimplCount
    sc' SimplCount -> IO ((), SimplCount) -> IO ((), SimplCount)
    forall a b. a -> b -> b
    `seq` ((), SimplCount) -> IO ((), SimplCount)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return ((), SimplCount
    sc'))