From 23f1f67957d132610c3b998ae89c634bb874f815 Mon Sep 17 00:00:00 2001 From: "benl@ouroborus.net" Date: Thu, 11 Mar 2010 06:45:18 +0000 Subject: [PATCH] Comments only --- compiler/vectorise/VectMonad.hs | 92 +++++++++++++++++++++++++++++++-------- 1 file changed, 74 insertions(+), 18 deletions(-) diff --git a/compiler/vectorise/VectMonad.hs b/compiler/vectorise/VectMonad.hs index 98701f0..2649716 100644 --- a/compiler/vectorise/VectMonad.hs +++ b/compiler/vectorise/VectMonad.hs @@ -1,3 +1,5 @@ + +-- | The Vectorisation monad. module VectMonad ( Scope(..), VM, @@ -64,58 +66,59 @@ import SrcLoc ( noSrcSpan ) import Control.Monad +-- | Indicates what scope something (a variable) is in. data Scope a b = Global a | Local b --- ---------------------------------------------------------------------------- --- Vectorisation monad +-- | The global environment. data GlobalEnv = GlobalEnv { - -- Mapping from global variables to their vectorised versions. + -- | Mapping from global variables to their vectorised versions. -- global_vars :: VarEnv Var - -- Purely scalar variables. Code which mentions only these - -- variables doesn't have to be lifted. + -- | Purely scalar variables. Code which mentions only these + -- variables doesn't have to be lifted. , global_scalars :: VarSet - -- Exported variables which have a vectorised version + -- | Exported variables which have a vectorised version -- , global_exported_vars :: VarEnv (Var, Var) - -- Mapping from TyCons to their vectorised versions. - -- TyCons which do not have to be vectorised are mapped to - -- themselves. + -- | Mapping from TyCons to their vectorised versions. + -- TyCons which do not have to be vectorised are mapped to + -- themselves. -- , global_tycons :: NameEnv TyCon - -- Mapping from DataCons to their vectorised versions + -- | Mapping from DataCons to their vectorised versions -- , global_datacons :: NameEnv DataCon - -- Mapping from TyCons to their PA dfuns + -- | Mapping from TyCons to their PA dfuns -- , global_pa_funs :: NameEnv Var - -- Mapping from TyCons to their PR dfuns + -- | Mapping from TyCons to their PR dfuns , global_pr_funs :: NameEnv Var - -- Mapping from unboxed TyCons to their boxed versions + -- | Mapping from unboxed TyCons to their boxed versions , global_boxed_tycons :: NameEnv TyCon - -- External package inst-env & home-package inst-env for class - -- instances + -- | External package inst-env & home-package inst-env for class + -- instances -- , global_inst_env :: (InstEnv, InstEnv) - -- External package inst-env & home-package inst-env for family - -- instances + -- | External package inst-env & home-package inst-env for family + -- instances -- , global_fam_inst_env :: FamInstEnvs - -- Hoisted bindings + -- | Hoisted bindings , global_bindings :: [(Var, CoreExpr)] } +-- | The local environment. data LocalEnv = LocalEnv { -- Mapping from local variables to their vectorised and -- lifted versions @@ -133,6 +136,8 @@ data LocalEnv = LocalEnv { , local_bind_name :: FastString } + +-- | Create an initial global environment initGlobalEnv :: VectInfo -> (InstEnv, InstEnv) -> FamInstEnvs -> GlobalEnv initGlobalEnv info instEnvs famInstEnvs = GlobalEnv { @@ -149,6 +154,8 @@ initGlobalEnv info instEnvs famInstEnvs , global_bindings = [] } + +-- Operators on Global Environments ------------------------------------------- extendImportedVarsEnv :: [(Var, Var)] -> GlobalEnv -> GlobalEnv extendImportedVarsEnv ps genv = genv { global_vars = extendVarEnvList (global_vars genv) ps } @@ -183,6 +190,8 @@ setBoxedTyConsEnv :: [(Name, TyCon)] -> GlobalEnv -> GlobalEnv setBoxedTyConsEnv ps genv = genv { global_boxed_tycons = mkNameEnv ps } + +-- | Create an empty local environment. emptyLocalEnv :: LocalEnv emptyLocalEnv = LocalEnv { local_vars = emptyVarEnv @@ -206,6 +215,12 @@ updVectInfo env tyenv info , let name = getName from , Just to <- [lookupNameEnv (from_env env) name]] + +-- The Vectorisation Monad ---------------------------------------------------- + +-- Vectorisation can either succeed with new envionment and a value, +-- or return with failure. +-- data VResult a = Yes GlobalEnv LocalEnv a | No newtype VM a = VM { runVM :: Builtins -> GlobalEnv -> LocalEnv -> DsM (VResult a) } @@ -219,6 +234,7 @@ instance Monad VM where No -> return No +-- | Throw an error saying we can't vectorise something cantVectorise :: String -> SDoc -> a cantVectorise s d = pgmError . showSDocDump @@ -237,16 +253,23 @@ maybeCantVectoriseM s d p Just x -> return x Nothing -> cantVectorise s d + +-- Control -------------------------------------------------------------------- +-- | Return some result saying we've failed. noV :: VM a noV = VM $ \_ _ _ -> return No traceNoV :: String -> SDoc -> VM a traceNoV s d = pprTrace s d noV + +-- | If True then carry on, otherwise fail. ensureV :: Bool -> VM () ensureV False = noV ensureV True = return () + +-- | If True then return the first argument, otherwise fail. onlyIfV :: Bool -> VM a -> VM a onlyIfV b p = ensureV b >> p @@ -254,6 +277,10 @@ traceEnsureV :: String -> SDoc -> Bool -> VM () traceEnsureV s d False = traceNoV s d traceEnsureV _ _ True = return () + +-- | Try some vectorisation computaton. +-- If it succeeds then return Just the result, +-- otherwise return Nothing. tryV :: VM a -> VM (Maybe a) tryV (VM p) = VM $ \bi genv lenv -> do @@ -262,6 +289,7 @@ tryV (VM p) = VM $ \bi genv lenv -> Yes genv' lenv' x -> return (Yes genv' lenv' (Just x)) No -> return (Yes genv lenv Nothing) + maybeV :: VM (Maybe a) -> VM a maybeV p = maybe noV return =<< p @@ -279,6 +307,10 @@ fixV f = VM (\bi genv lenv -> fixDs $ \r -> runVM (f (unYes r)) bi genv lenv ) unYes (Yes _ _ x) = x unYes No = panic "VectMonad.fixV: no result" + +-- Local Environments --------------------------------------------------------- +-- | Perform a computation in its own local environment. +-- This does not alter the environment of the current state. localV :: VM a -> VM a localV p = do env <- readLEnv id @@ -286,6 +318,7 @@ localV p = do setLEnv env return x +-- | Perform a computation in an empty local environment. closedV :: VM a -> VM a closedV p = do env <- readLEnv id @@ -294,18 +327,29 @@ closedV p = do setLEnv env return x +-- Lifting -------------------------------------------------------------------- +-- | Lift a desugaring computation into the vectorisation monad. liftDs :: DsM a -> VM a liftDs p = VM $ \_ genv lenv -> do { x <- p; return (Yes genv lenv x) } + + +-- Builtins ------------------------------------------------------------------- +-- Operations on Builtins liftBuiltinDs :: (Builtins -> DsM a) -> VM a liftBuiltinDs p = VM $ \bi genv lenv -> do { x <- p bi; return (Yes genv lenv x)} + +-- | Project something from the set of builtins. builtin :: (Builtins -> a) -> VM a builtin f = VM $ \bi genv lenv -> return (Yes genv lenv (f bi)) builtins :: (a -> Builtins -> b) -> VM (a -> b) builtins f = VM $ \bi genv lenv -> return (Yes genv lenv (`f` bi)) + +-- Environments --------------------------------------------------------------- +-- | Project something from the global environment. readGEnv :: (GlobalEnv -> a) -> VM a readGEnv f = VM $ \_ genv lenv -> return (Yes genv lenv (f genv)) @@ -315,6 +359,8 @@ setGEnv genv = VM $ \_ _ lenv -> return (Yes genv lenv ()) updGEnv :: (GlobalEnv -> GlobalEnv) -> VM () updGEnv f = VM $ \_ genv lenv -> return (Yes (f genv) lenv ()) + +-- | Project something from the local environment. readLEnv :: (LocalEnv -> a) -> VM a readLEnv f = VM $ \_ genv lenv -> return (Yes genv lenv (f lenv)) @@ -324,12 +370,17 @@ setLEnv lenv = VM $ \_ genv _ -> return (Yes genv lenv ()) updLEnv :: (LocalEnv -> LocalEnv) -> VM () updLEnv f = VM $ \_ genv lenv -> return (Yes genv (f lenv) ()) + +-- InstEnv -------------------------------------------------------------------- getInstEnv :: VM (InstEnv, InstEnv) getInstEnv = readGEnv global_inst_env getFamInstEnv :: VM FamInstEnvs getFamInstEnv = readGEnv global_fam_inst_env + +-- Names ---------------------------------------------------------------------- +-- | Get the name of the local binding currently being vectorised. getBindName :: VM FastString getBindName = readLEnv local_bind_name @@ -356,6 +407,7 @@ cloneId mk_occ id ty | otherwise = Id.mkLocalId name ty return id' +-- Make a fresh instance of this var, with a new unique. cloneVar :: Var -> VM Var cloneVar var = liftM (setIdUnique var) (liftDs newUnique) @@ -396,6 +448,10 @@ defGlobalVar v v' = updGEnv $ \env -> upd env | isExportedId v = extendVarEnv env v (v, v') | otherwise = env +-- | Lookup the vectorised and\/or lifted versions of this variable. +-- If it's in the global environment we get the vectorised version. +-- If it's in the local environment we get both the vectorised and lifted version. +-- lookupVar :: Var -> VM (Scope Var (Var, Var)) lookupVar v = do -- 1.7.10.4