diff options
Diffstat (limited to 'compiler/GHC/Cmm/Dataflow')
| -rw-r--r-- | compiler/GHC/Cmm/Dataflow/Block.hs | 329 | ||||
| -rw-r--r-- | compiler/GHC/Cmm/Dataflow/Collections.hs | 177 | ||||
| -rw-r--r-- | compiler/GHC/Cmm/Dataflow/Graph.hs | 186 | ||||
| -rw-r--r-- | compiler/GHC/Cmm/Dataflow/Label.hs | 142 |
4 files changed, 834 insertions, 0 deletions
diff --git a/compiler/GHC/Cmm/Dataflow/Block.hs b/compiler/GHC/Cmm/Dataflow/Block.hs new file mode 100644 index 0000000000..d2e52a8904 --- /dev/null +++ b/compiler/GHC/Cmm/Dataflow/Block.hs @@ -0,0 +1,329 @@ +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE DeriveFunctor #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE PolyKinds #-} +{-# LANGUAGE RankNTypes #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE StandaloneDeriving #-} +{-# LANGUAGE TypeFamilies #-} +module GHC.Cmm.Dataflow.Block + ( Extensibility (..) + , O + , C + , MaybeO(..) + , IndexedCO + , Block(..) + , blockAppend + , blockCons + , blockFromList + , blockJoin + , blockJoinHead + , blockJoinTail + , blockSnoc + , blockSplit + , blockSplitHead + , blockSplitTail + , blockToList + , emptyBlock + , firstNode + , foldBlockNodesB + , foldBlockNodesB3 + , foldBlockNodesF + , isEmptyBlock + , lastNode + , mapBlock + , mapBlock' + , mapBlock3' + , replaceFirstNode + , replaceLastNode + ) where + +import GhcPrelude + +-- ----------------------------------------------------------------------------- +-- Shapes: Open and Closed + +-- | Used at the type level to indicate "open" vs "closed" structure. +data Extensibility + -- | An "open" structure with a unique, unnamed control-flow edge flowing in + -- or out. "Fallthrough" and concatenation are permitted at an open point. + = Open + -- | A "closed" structure which supports control transfer only through the use + -- of named labels---no "fallthrough" is permitted. The number of control-flow + -- edges is unconstrained. + | Closed + +type O = 'Open +type C = 'Closed + +-- | Either type indexed by closed/open using type families +type family IndexedCO (ex :: Extensibility) (a :: k) (b :: k) :: k +type instance IndexedCO C a _b = a +type instance IndexedCO O _a b = b + +-- | Maybe type indexed by open/closed +data MaybeO ex t where + JustO :: t -> MaybeO O t + NothingO :: MaybeO C t + +-- | Maybe type indexed by closed/open +data MaybeC ex t where + JustC :: t -> MaybeC C t + NothingC :: MaybeC O t + +deriving instance Functor (MaybeO ex) +deriving instance Functor (MaybeC ex) + +-- ----------------------------------------------------------------------------- +-- The Block type + +-- | A sequence of nodes. May be any of four shapes (O/O, O/C, C/O, C/C). +-- Open at the entry means single entry, mutatis mutandis for exit. +-- A closed/closed block is a /basic/ block and can't be extended further. +-- Clients should avoid manipulating blocks and should stick to either nodes +-- or graphs. +data Block n e x where + BlockCO :: n C O -> Block n O O -> Block n C O + BlockCC :: n C O -> Block n O O -> n O C -> Block n C C + BlockOC :: Block n O O -> n O C -> Block n O C + + BNil :: Block n O O + BMiddle :: n O O -> Block n O O + BCat :: Block n O O -> Block n O O -> Block n O O + BSnoc :: Block n O O -> n O O -> Block n O O + BCons :: n O O -> Block n O O -> Block n O O + + +-- ----------------------------------------------------------------------------- +-- Simple operations on Blocks + +-- Predicates + +isEmptyBlock :: Block n e x -> Bool +isEmptyBlock BNil = True +isEmptyBlock (BCat l r) = isEmptyBlock l && isEmptyBlock r +isEmptyBlock _ = False + + +-- Building + +emptyBlock :: Block n O O +emptyBlock = BNil + +blockCons :: n O O -> Block n O x -> Block n O x +blockCons n b = case b of + BlockOC b l -> (BlockOC $! (n `blockCons` b)) l + BNil{} -> BMiddle n + BMiddle{} -> n `BCons` b + BCat{} -> n `BCons` b + BSnoc{} -> n `BCons` b + BCons{} -> n `BCons` b + +blockSnoc :: Block n e O -> n O O -> Block n e O +blockSnoc b n = case b of + BlockCO f b -> BlockCO f $! (b `blockSnoc` n) + BNil{} -> BMiddle n + BMiddle{} -> b `BSnoc` n + BCat{} -> b `BSnoc` n + BSnoc{} -> b `BSnoc` n + BCons{} -> b `BSnoc` n + +blockJoinHead :: n C O -> Block n O x -> Block n C x +blockJoinHead f (BlockOC b l) = BlockCC f b l +blockJoinHead f b = BlockCO f BNil `cat` b + +blockJoinTail :: Block n e O -> n O C -> Block n e C +blockJoinTail (BlockCO f b) t = BlockCC f b t +blockJoinTail b t = b `cat` BlockOC BNil t + +blockJoin :: n C O -> Block n O O -> n O C -> Block n C C +blockJoin f b t = BlockCC f b t + +blockAppend :: Block n e O -> Block n O x -> Block n e x +blockAppend = cat + + +-- Taking apart + +firstNode :: Block n C x -> n C O +firstNode (BlockCO n _) = n +firstNode (BlockCC n _ _) = n + +lastNode :: Block n x C -> n O C +lastNode (BlockOC _ n) = n +lastNode (BlockCC _ _ n) = n + +blockSplitHead :: Block n C x -> (n C O, Block n O x) +blockSplitHead (BlockCO n b) = (n, b) +blockSplitHead (BlockCC n b t) = (n, BlockOC b t) + +blockSplitTail :: Block n e C -> (Block n e O, n O C) +blockSplitTail (BlockOC b n) = (b, n) +blockSplitTail (BlockCC f b t) = (BlockCO f b, t) + +-- | Split a closed block into its entry node, open middle block, and +-- exit node. +blockSplit :: Block n C C -> (n C O, Block n O O, n O C) +blockSplit (BlockCC f b t) = (f, b, t) + +blockToList :: Block n O O -> [n O O] +blockToList b = go b [] + where go :: Block n O O -> [n O O] -> [n O O] + go BNil r = r + go (BMiddle n) r = n : r + go (BCat b1 b2) r = go b1 $! go b2 r + go (BSnoc b1 n) r = go b1 (n:r) + go (BCons n b1) r = n : go b1 r + +blockFromList :: [n O O] -> Block n O O +blockFromList = foldr BCons BNil + +-- Modifying + +replaceFirstNode :: Block n C x -> n C O -> Block n C x +replaceFirstNode (BlockCO _ b) f = BlockCO f b +replaceFirstNode (BlockCC _ b n) f = BlockCC f b n + +replaceLastNode :: Block n x C -> n O C -> Block n x C +replaceLastNode (BlockOC b _) n = BlockOC b n +replaceLastNode (BlockCC l b _) n = BlockCC l b n + +-- ----------------------------------------------------------------------------- +-- General concatenation + +cat :: Block n e O -> Block n O x -> Block n e x +cat x y = case x of + BNil -> y + + BlockCO l b1 -> case y of + BlockOC b2 n -> (BlockCC l $! (b1 `cat` b2)) n + BNil -> x + BMiddle _ -> BlockCO l $! (b1 `cat` y) + BCat{} -> BlockCO l $! (b1 `cat` y) + BSnoc{} -> BlockCO l $! (b1 `cat` y) + BCons{} -> BlockCO l $! (b1 `cat` y) + + BMiddle n -> case y of + BlockOC b2 n2 -> (BlockOC $! (x `cat` b2)) n2 + BNil -> x + BMiddle{} -> BCons n y + BCat{} -> BCons n y + BSnoc{} -> BCons n y + BCons{} -> BCons n y + + BCat{} -> case y of + BlockOC b3 n2 -> (BlockOC $! (x `cat` b3)) n2 + BNil -> x + BMiddle n -> BSnoc x n + BCat{} -> BCat x y + BSnoc{} -> BCat x y + BCons{} -> BCat x y + + BSnoc{} -> case y of + BlockOC b2 n2 -> (BlockOC $! (x `cat` b2)) n2 + BNil -> x + BMiddle n -> BSnoc x n + BCat{} -> BCat x y + BSnoc{} -> BCat x y + BCons{} -> BCat x y + + + BCons{} -> case y of + BlockOC b2 n2 -> (BlockOC $! (x `cat` b2)) n2 + BNil -> x + BMiddle n -> BSnoc x n + BCat{} -> BCat x y + BSnoc{} -> BCat x y + BCons{} -> BCat x y + + +-- ----------------------------------------------------------------------------- +-- Mapping + +-- | map a function over the nodes of a 'Block' +mapBlock :: (forall e x. n e x -> n' e x) -> Block n e x -> Block n' e x +mapBlock f (BlockCO n b ) = BlockCO (f n) (mapBlock f b) +mapBlock f (BlockOC b n) = BlockOC (mapBlock f b) (f n) +mapBlock f (BlockCC n b m) = BlockCC (f n) (mapBlock f b) (f m) +mapBlock _ BNil = BNil +mapBlock f (BMiddle n) = BMiddle (f n) +mapBlock f (BCat b1 b2) = BCat (mapBlock f b1) (mapBlock f b2) +mapBlock f (BSnoc b n) = BSnoc (mapBlock f b) (f n) +mapBlock f (BCons n b) = BCons (f n) (mapBlock f b) + +-- | A strict 'mapBlock' +mapBlock' :: (forall e x. n e x -> n' e x) -> (Block n e x -> Block n' e x) +mapBlock' f = mapBlock3' (f, f, f) + +-- | map over a block, with different functions to apply to first nodes, +-- middle nodes and last nodes respectively. The map is strict. +-- +mapBlock3' :: forall n n' e x . + ( n C O -> n' C O + , n O O -> n' O O, + n O C -> n' O C) + -> Block n e x -> Block n' e x +mapBlock3' (f, m, l) b = go b + where go :: forall e x . Block n e x -> Block n' e x + go (BlockOC b y) = (BlockOC $! go b) $! l y + go (BlockCO x b) = (BlockCO $! f x) $! (go b) + go (BlockCC x b y) = ((BlockCC $! f x) $! go b) $! (l y) + go BNil = BNil + go (BMiddle n) = BMiddle $! m n + go (BCat x y) = (BCat $! go x) $! (go y) + go (BSnoc x n) = (BSnoc $! go x) $! (m n) + go (BCons n x) = (BCons $! m n) $! (go x) + +-- ----------------------------------------------------------------------------- +-- Folding + + +-- | Fold a function over every node in a block, forward or backward. +-- The fold function must be polymorphic in the shape of the nodes. +foldBlockNodesF3 :: forall n a b c . + ( n C O -> a -> b + , n O O -> b -> b + , n O C -> b -> c) + -> (forall e x . Block n e x -> IndexedCO e a b -> IndexedCO x c b) +foldBlockNodesF :: forall n a . + (forall e x . n e x -> a -> a) + -> (forall e x . Block n e x -> IndexedCO e a a -> IndexedCO x a a) +foldBlockNodesB3 :: forall n a b c . + ( n C O -> b -> c + , n O O -> b -> b + , n O C -> a -> b) + -> (forall e x . Block n e x -> IndexedCO x a b -> IndexedCO e c b) +foldBlockNodesB :: forall n a . + (forall e x . n e x -> a -> a) + -> (forall e x . Block n e x -> IndexedCO x a a -> IndexedCO e a a) + +foldBlockNodesF3 (ff, fm, fl) = block + where block :: forall e x . Block n e x -> IndexedCO e a b -> IndexedCO x c b + block (BlockCO f b ) = ff f `cat` block b + block (BlockCC f b l) = ff f `cat` block b `cat` fl l + block (BlockOC b l) = block b `cat` fl l + block BNil = id + block (BMiddle node) = fm node + block (b1 `BCat` b2) = block b1 `cat` block b2 + block (b1 `BSnoc` n) = block b1 `cat` fm n + block (n `BCons` b2) = fm n `cat` block b2 + cat :: forall a b c. (a -> b) -> (b -> c) -> a -> c + cat f f' = f' . f + +foldBlockNodesF f = foldBlockNodesF3 (f, f, f) + +foldBlockNodesB3 (ff, fm, fl) = block + where block :: forall e x . Block n e x -> IndexedCO x a b -> IndexedCO e c b + block (BlockCO f b ) = ff f `cat` block b + block (BlockCC f b l) = ff f `cat` block b `cat` fl l + block (BlockOC b l) = block b `cat` fl l + block BNil = id + block (BMiddle node) = fm node + block (b1 `BCat` b2) = block b1 `cat` block b2 + block (b1 `BSnoc` n) = block b1 `cat` fm n + block (n `BCons` b2) = fm n `cat` block b2 + cat :: forall a b c. (b -> c) -> (a -> b) -> a -> c + cat f f' = f . f' + +foldBlockNodesB f = foldBlockNodesB3 (f, f, f) + diff --git a/compiler/GHC/Cmm/Dataflow/Collections.hs b/compiler/GHC/Cmm/Dataflow/Collections.hs new file mode 100644 index 0000000000..f131f17cc1 --- /dev/null +++ b/compiler/GHC/Cmm/Dataflow/Collections.hs @@ -0,0 +1,177 @@ +{-# LANGUAGE DeriveFunctor #-} +{-# LANGUAGE DeriveTraversable #-} +{-# LANGUAGE DeriveFoldable #-} +{-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} + +module GHC.Cmm.Dataflow.Collections + ( IsSet(..) + , setInsertList, setDeleteList, setUnions + , IsMap(..) + , mapInsertList, mapDeleteList, mapUnions + , UniqueMap, UniqueSet + ) where + +import GhcPrelude + +import qualified Data.IntMap.Strict as M +import qualified Data.IntSet as S + +import Data.List (foldl1') + +class IsSet set where + type ElemOf set + + setNull :: set -> Bool + setSize :: set -> Int + setMember :: ElemOf set -> set -> Bool + + setEmpty :: set + setSingleton :: ElemOf set -> set + setInsert :: ElemOf set -> set -> set + setDelete :: ElemOf set -> set -> set + + setUnion :: set -> set -> set + setDifference :: set -> set -> set + setIntersection :: set -> set -> set + setIsSubsetOf :: set -> set -> Bool + setFilter :: (ElemOf set -> Bool) -> set -> set + + setFoldl :: (b -> ElemOf set -> b) -> b -> set -> b + setFoldr :: (ElemOf set -> b -> b) -> b -> set -> b + + setElems :: set -> [ElemOf set] + setFromList :: [ElemOf set] -> set + +-- Helper functions for IsSet class +setInsertList :: IsSet set => [ElemOf set] -> set -> set +setInsertList keys set = foldl' (flip setInsert) set keys + +setDeleteList :: IsSet set => [ElemOf set] -> set -> set +setDeleteList keys set = foldl' (flip setDelete) set keys + +setUnions :: IsSet set => [set] -> set +setUnions [] = setEmpty +setUnions sets = foldl1' setUnion sets + + +class IsMap map where + type KeyOf map + + mapNull :: map a -> Bool + mapSize :: map a -> Int + mapMember :: KeyOf map -> map a -> Bool + mapLookup :: KeyOf map -> map a -> Maybe a + mapFindWithDefault :: a -> KeyOf map -> map a -> a + + mapEmpty :: map a + mapSingleton :: KeyOf map -> a -> map a + mapInsert :: KeyOf map -> a -> map a -> map a + mapInsertWith :: (a -> a -> a) -> KeyOf map -> a -> map a -> map a + mapDelete :: KeyOf map -> map a -> map a + mapAlter :: (Maybe a -> Maybe a) -> KeyOf map -> map a -> map a + mapAdjust :: (a -> a) -> KeyOf map -> map a -> map a + + mapUnion :: map a -> map a -> map a + mapUnionWithKey :: (KeyOf map -> a -> a -> a) -> map a -> map a -> map a + mapDifference :: map a -> map a -> map a + mapIntersection :: map a -> map a -> map a + mapIsSubmapOf :: Eq a => map a -> map a -> Bool + + mapMap :: (a -> b) -> map a -> map b + mapMapWithKey :: (KeyOf map -> a -> b) -> map a -> map b + mapFoldl :: (b -> a -> b) -> b -> map a -> b + mapFoldr :: (a -> b -> b) -> b -> map a -> b + mapFoldlWithKey :: (b -> KeyOf map -> a -> b) -> b -> map a -> b + mapFoldMapWithKey :: Monoid m => (KeyOf map -> a -> m) -> map a -> m + mapFilter :: (a -> Bool) -> map a -> map a + mapFilterWithKey :: (KeyOf map -> a -> Bool) -> map a -> map a + + + mapElems :: map a -> [a] + mapKeys :: map a -> [KeyOf map] + mapToList :: map a -> [(KeyOf map, a)] + mapFromList :: [(KeyOf map, a)] -> map a + mapFromListWith :: (a -> a -> a) -> [(KeyOf map,a)] -> map a + +-- Helper functions for IsMap class +mapInsertList :: IsMap map => [(KeyOf map, a)] -> map a -> map a +mapInsertList assocs map = foldl' (flip (uncurry mapInsert)) map assocs + +mapDeleteList :: IsMap map => [KeyOf map] -> map a -> map a +mapDeleteList keys map = foldl' (flip mapDelete) map keys + +mapUnions :: IsMap map => [map a] -> map a +mapUnions [] = mapEmpty +mapUnions maps = foldl1' mapUnion maps + +----------------------------------------------------------------------------- +-- Basic instances +----------------------------------------------------------------------------- + +newtype UniqueSet = US S.IntSet deriving (Eq, Ord, Show, Semigroup, Monoid) + +instance IsSet UniqueSet where + type ElemOf UniqueSet = Int + + setNull (US s) = S.null s + setSize (US s) = S.size s + setMember k (US s) = S.member k s + + setEmpty = US S.empty + setSingleton k = US (S.singleton k) + setInsert k (US s) = US (S.insert k s) + setDelete k (US s) = US (S.delete k s) + + setUnion (US x) (US y) = US (S.union x y) + setDifference (US x) (US y) = US (S.difference x y) + setIntersection (US x) (US y) = US (S.intersection x y) + setIsSubsetOf (US x) (US y) = S.isSubsetOf x y + setFilter f (US s) = US (S.filter f s) + + setFoldl k z (US s) = S.foldl' k z s + setFoldr k z (US s) = S.foldr k z s + + setElems (US s) = S.elems s + setFromList ks = US (S.fromList ks) + +newtype UniqueMap v = UM (M.IntMap v) + deriving (Eq, Ord, Show, Functor, Foldable, Traversable) + +instance IsMap UniqueMap where + type KeyOf UniqueMap = Int + + mapNull (UM m) = M.null m + mapSize (UM m) = M.size m + mapMember k (UM m) = M.member k m + mapLookup k (UM m) = M.lookup k m + mapFindWithDefault def k (UM m) = M.findWithDefault def k m + + mapEmpty = UM M.empty + mapSingleton k v = UM (M.singleton k v) + mapInsert k v (UM m) = UM (M.insert k v m) + mapInsertWith f k v (UM m) = UM (M.insertWith f k v m) + mapDelete k (UM m) = UM (M.delete k m) + mapAlter f k (UM m) = UM (M.alter f k m) + mapAdjust f k (UM m) = UM (M.adjust f k m) + + mapUnion (UM x) (UM y) = UM (M.union x y) + mapUnionWithKey f (UM x) (UM y) = UM (M.unionWithKey f x y) + mapDifference (UM x) (UM y) = UM (M.difference x y) + mapIntersection (UM x) (UM y) = UM (M.intersection x y) + mapIsSubmapOf (UM x) (UM y) = M.isSubmapOf x y + + mapMap f (UM m) = UM (M.map f m) + mapMapWithKey f (UM m) = UM (M.mapWithKey f m) + mapFoldl k z (UM m) = M.foldl' k z m + mapFoldr k z (UM m) = M.foldr k z m + mapFoldlWithKey k z (UM m) = M.foldlWithKey' k z m + mapFoldMapWithKey f (UM m) = M.foldMapWithKey f m + mapFilter f (UM m) = UM (M.filter f m) + mapFilterWithKey f (UM m) = UM (M.filterWithKey f m) + + mapElems (UM m) = M.elems m + mapKeys (UM m) = M.keys m + mapToList (UM m) = M.toList m + mapFromList assocs = UM (M.fromList assocs) + mapFromListWith f assocs = UM (M.fromListWith f assocs) diff --git a/compiler/GHC/Cmm/Dataflow/Graph.hs b/compiler/GHC/Cmm/Dataflow/Graph.hs new file mode 100644 index 0000000000..3f361de0fb --- /dev/null +++ b/compiler/GHC/Cmm/Dataflow/Graph.hs @@ -0,0 +1,186 @@ +{-# LANGUAGE BangPatterns #-} +{-# LANGUAGE DataKinds #-} +{-# LANGUAGE FlexibleInstances #-} +{-# LANGUAGE GADTs #-} +{-# LANGUAGE RankNTypes #-} +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE TypeFamilies #-} +module GHC.Cmm.Dataflow.Graph + ( Body + , Graph + , Graph'(..) + , NonLocal(..) + , addBlock + , bodyList + , emptyBody + , labelsDefined + , mapGraph + , mapGraphBlocks + , revPostorderFrom + ) where + + +import GhcPrelude +import Util + +import GHC.Cmm.Dataflow.Label +import GHC.Cmm.Dataflow.Block +import GHC.Cmm.Dataflow.Collections + +-- | A (possibly empty) collection of closed/closed blocks +type Body n = LabelMap (Block n C C) + +-- | @Body@ abstracted over @block@ +type Body' block (n :: Extensibility -> Extensibility -> *) = LabelMap (block n C C) + +------------------------------- +-- | Gives access to the anchor points for +-- nonlocal edges as well as the edges themselves +class NonLocal thing where + entryLabel :: thing C x -> Label -- ^ The label of a first node or block + successors :: thing e C -> [Label] -- ^ Gives control-flow successors + +instance NonLocal n => NonLocal (Block n) where + entryLabel (BlockCO f _) = entryLabel f + entryLabel (BlockCC f _ _) = entryLabel f + + successors (BlockOC _ n) = successors n + successors (BlockCC _ _ n) = successors n + + +emptyBody :: Body' block n +emptyBody = mapEmpty + +bodyList :: Body' block n -> [(Label,block n C C)] +bodyList body = mapToList body + +addBlock + :: (NonLocal block, HasDebugCallStack) + => block C C -> LabelMap (block C C) -> LabelMap (block C C) +addBlock block body = mapAlter add lbl body + where + lbl = entryLabel block + add Nothing = Just block + add _ = error $ "duplicate label " ++ show lbl ++ " in graph" + + +-- --------------------------------------------------------------------------- +-- Graph + +-- | A control-flow graph, which may take any of four shapes (O/O, +-- O/C, C/O, C/C). A graph open at the entry has a single, +-- distinguished, anonymous entry point; if a graph is closed at the +-- entry, its entry point(s) are supplied by a context. +type Graph = Graph' Block + +-- | @Graph'@ is abstracted over the block type, so that we can build +-- graphs of annotated blocks for example (Compiler.Hoopl.Dataflow +-- needs this). +data Graph' block (n :: Extensibility -> Extensibility -> *) e x where + GNil :: Graph' block n O O + GUnit :: block n O O -> Graph' block n O O + GMany :: MaybeO e (block n O C) + -> Body' block n + -> MaybeO x (block n C O) + -> Graph' block n e x + + +-- ----------------------------------------------------------------------------- +-- Mapping over graphs + +-- | Maps over all nodes in a graph. +mapGraph :: (forall e x. n e x -> n' e x) -> Graph n e x -> Graph n' e x +mapGraph f = mapGraphBlocks (mapBlock f) + +-- | Function 'mapGraphBlocks' enables a change of representation of blocks, +-- nodes, or both. It lifts a polymorphic block transform into a polymorphic +-- graph transform. When the block representation stabilizes, a similar +-- function should be provided for blocks. +mapGraphBlocks :: forall block n block' n' e x . + (forall e x . block n e x -> block' n' e x) + -> (Graph' block n e x -> Graph' block' n' e x) + +mapGraphBlocks f = map + where map :: Graph' block n e x -> Graph' block' n' e x + map GNil = GNil + map (GUnit b) = GUnit (f b) + map (GMany e b x) = GMany (fmap f e) (mapMap f b) (fmap f x) + +-- ----------------------------------------------------------------------------- +-- Extracting Labels from graphs + +labelsDefined :: forall block n e x . NonLocal (block n) => Graph' block n e x + -> LabelSet +labelsDefined GNil = setEmpty +labelsDefined (GUnit{}) = setEmpty +labelsDefined (GMany _ body x) = mapFoldlWithKey addEntry (exitLabel x) body + where addEntry :: forall a. LabelSet -> ElemOf LabelSet -> a -> LabelSet + addEntry labels label _ = setInsert label labels + exitLabel :: MaybeO x (block n C O) -> LabelSet + exitLabel NothingO = setEmpty + exitLabel (JustO b) = setSingleton (entryLabel b) + + +---------------------------------------------------------------- + +-- | Returns a list of blocks reachable from the provided Labels in the reverse +-- postorder. +-- +-- This is the most important traversal over this data structure. It drops +-- unreachable code and puts blocks in an order that is good for solving forward +-- dataflow problems quickly. The reverse order is good for solving backward +-- dataflow problems quickly. The forward order is also reasonably good for +-- emitting instructions, except that it will not usually exploit Forrest +-- Baskett's trick of eliminating the unconditional branch from a loop. For +-- that you would need a more serious analysis, probably based on dominators, to +-- identify loop headers. +-- +-- For forward analyses we want reverse postorder visitation, consider: +-- @ +-- A -> [B,C] +-- B -> D +-- C -> D +-- @ +-- Postorder: [D, C, B, A] (or [D, B, C, A]) +-- Reverse postorder: [A, B, C, D] (or [A, C, B, D]) +-- This matters for, e.g., forward analysis, because we want to analyze *both* +-- B and C before we analyze D. +revPostorderFrom + :: forall block. (NonLocal block) + => LabelMap (block C C) -> Label -> [block C C] +revPostorderFrom graph start = go start_worklist setEmpty [] + where + start_worklist = lookup_for_descend start Nil + + -- To compute the postorder we need to "visit" a block (mark as done) + -- *after* visiting all its successors. So we need to know whether we + -- already processed all successors of each block (and @NonLocal@ allows + -- arbitrary many successors). So we use an explicit stack with an extra bit + -- of information: + -- * @ConsTodo@ means to explore the block if it wasn't visited before + -- * @ConsMark@ means that all successors were already done and we can add + -- the block to the result. + -- + -- NOTE: We add blocks to the result list in postorder, but we *prepend* + -- them (i.e., we use @(:)@), which means that the final list is in reverse + -- postorder. + go :: DfsStack (block C C) -> LabelSet -> [block C C] -> [block C C] + go Nil !_ !result = result + go (ConsMark block rest) !wip_or_done !result = + go rest wip_or_done (block : result) + go (ConsTodo block rest) !wip_or_done !result + | entryLabel block `setMember` wip_or_done = go rest wip_or_done result + | otherwise = + let new_worklist = + foldr lookup_for_descend + (ConsMark block rest) + (successors block) + in go new_worklist (setInsert (entryLabel block) wip_or_done) result + + lookup_for_descend :: Label -> DfsStack (block C C) -> DfsStack (block C C) + lookup_for_descend label wl + | Just b <- mapLookup label graph = ConsTodo b wl + | otherwise = + error $ "Label that doesn't have a block?! " ++ show label + +data DfsStack a = ConsTodo a (DfsStack a) | ConsMark a (DfsStack a) | Nil diff --git a/compiler/GHC/Cmm/Dataflow/Label.hs b/compiler/GHC/Cmm/Dataflow/Label.hs new file mode 100644 index 0000000000..c571cedb48 --- /dev/null +++ b/compiler/GHC/Cmm/Dataflow/Label.hs @@ -0,0 +1,142 @@ +{-# LANGUAGE DeriveFoldable #-} +{-# LANGUAGE DeriveFunctor #-} +{-# LANGUAGE DeriveTraversable #-} +{-# LANGUAGE TypeFamilies #-} +{-# LANGUAGE GeneralizedNewtypeDeriving #-} + +module GHC.Cmm.Dataflow.Label + ( Label + , LabelMap + , LabelSet + , FactBase + , lookupFact + , mkHooplLabel + ) where + +import GhcPrelude + +import Outputable + +-- TODO: This should really just use GHC's Unique and Uniq{Set,FM} +import GHC.Cmm.Dataflow.Collections + +import Unique (Uniquable(..)) +import TrieMap + + +----------------------------------------------------------------------------- +-- Label +----------------------------------------------------------------------------- + +newtype Label = Label { lblToUnique :: Int } + deriving (Eq, Ord) + +mkHooplLabel :: Int -> Label +mkHooplLabel = Label + +instance Show Label where + show (Label n) = "L" ++ show n + +instance Uniquable Label where + getUnique label = getUnique (lblToUnique label) + +instance Outputable Label where + ppr label = ppr (getUnique label) + +----------------------------------------------------------------------------- +-- LabelSet + +newtype LabelSet = LS UniqueSet deriving (Eq, Ord, Show, Monoid, Semigroup) + +instance IsSet LabelSet where + type ElemOf LabelSet = Label + + setNull (LS s) = setNull s + setSize (LS s) = setSize s + setMember (Label k) (LS s) = setMember k s + + setEmpty = LS setEmpty + setSingleton (Label k) = LS (setSingleton k) + setInsert (Label k) (LS s) = LS (setInsert k s) + setDelete (Label k) (LS s) = LS (setDelete k s) + + setUnion (LS x) (LS y) = LS (setUnion x y) + setDifference (LS x) (LS y) = LS (setDifference x y) + setIntersection (LS x) (LS y) = LS (setIntersection x y) + setIsSubsetOf (LS x) (LS y) = setIsSubsetOf x y + setFilter f (LS s) = LS (setFilter (f . mkHooplLabel) s) + setFoldl k z (LS s) = setFoldl (\a v -> k a (mkHooplLabel v)) z s + setFoldr k z (LS s) = setFoldr (\v a -> k (mkHooplLabel v) a) z s + + setElems (LS s) = map mkHooplLabel (setElems s) + setFromList ks = LS (setFromList (map lblToUnique ks)) + +----------------------------------------------------------------------------- +-- LabelMap + +newtype LabelMap v = LM (UniqueMap v) + deriving (Eq, Ord, Show, Functor, Foldable, Traversable) + +instance IsMap LabelMap where + type KeyOf LabelMap = Label + + mapNull (LM m) = mapNull m + mapSize (LM m) = mapSize m + mapMember (Label k) (LM m) = mapMember k m + mapLookup (Label k) (LM m) = mapLookup k m + mapFindWithDefault def (Label k) (LM m) = mapFindWithDefault def k m + + mapEmpty = LM mapEmpty + mapSingleton (Label k) v = LM (mapSingleton k v) + mapInsert (Label k) v (LM m) = LM (mapInsert k v m) + mapInsertWith f (Label k) v (LM m) = LM (mapInsertWith f k v m) + mapDelete (Label k) (LM m) = LM (mapDelete k m) + mapAlter f (Label k) (LM m) = LM (mapAlter f k m) + mapAdjust f (Label k) (LM m) = LM (mapAdjust f k m) + + mapUnion (LM x) (LM y) = LM (mapUnion x y) + mapUnionWithKey f (LM x) (LM y) = LM (mapUnionWithKey (f . mkHooplLabel) x y) + mapDifference (LM x) (LM y) = LM (mapDifference x y) + mapIntersection (LM x) (LM y) = LM (mapIntersection x y) + mapIsSubmapOf (LM x) (LM y) = mapIsSubmapOf x y + + mapMap f (LM m) = LM (mapMap f m) + mapMapWithKey f (LM m) = LM (mapMapWithKey (f . mkHooplLabel) m) + mapFoldl k z (LM m) = mapFoldl k z m + mapFoldr k z (LM m) = mapFoldr k z m + mapFoldlWithKey k z (LM m) = + mapFoldlWithKey (\a v -> k a (mkHooplLabel v)) z m + mapFoldMapWithKey f (LM m) = mapFoldMapWithKey (\k v -> f (mkHooplLabel k) v) m + mapFilter f (LM m) = LM (mapFilter f m) + mapFilterWithKey f (LM m) = LM (mapFilterWithKey (f . mkHooplLabel) m) + + mapElems (LM m) = mapElems m + mapKeys (LM m) = map mkHooplLabel (mapKeys m) + mapToList (LM m) = [(mkHooplLabel k, v) | (k, v) <- mapToList m] + mapFromList assocs = LM (mapFromList [(lblToUnique k, v) | (k, v) <- assocs]) + mapFromListWith f assocs = LM (mapFromListWith f [(lblToUnique k, v) | (k, v) <- assocs]) + +----------------------------------------------------------------------------- +-- Instances + +instance Outputable LabelSet where + ppr = ppr . setElems + +instance Outputable a => Outputable (LabelMap a) where + ppr = ppr . mapToList + +instance TrieMap LabelMap where + type Key LabelMap = Label + emptyTM = mapEmpty + lookupTM k m = mapLookup k m + alterTM k f m = mapAlter f k m + foldTM k m z = mapFoldr k z m + mapTM f m = mapMap f m + +----------------------------------------------------------------------------- +-- FactBase + +type FactBase f = LabelMap f + +lookupFact :: Label -> FactBase f -> Maybe f +lookupFact = mapLookup |