hoopl-3.10.0.1: A library to support dataflow analysis and optimization

Safe HaskellSafe
LanguageHaskell2010

Compiler.Hoopl

Contents

Synopsis

Body

type Body n = LabelMap (Block n C C)

A (possibly empty) collection of closed/closed blocks

type Body' block n = LabelMap (block n C C)

Body abstracted over block

emptyBody :: Body' block n

bodyList :: NonLocal (block n) => Body' block n -> [(Label, block n C C)]

addBlock :: NonLocal thing => thing C C -> LabelMap (thing C C) -> LabelMap (thing C C)

bodyUnion :: forall a. LabelMap a -> LabelMap a -> LabelMap a

Graph

type Graph = Graph' Block

A control-flow graph, which may take any of four shapes (O/O, OC, CO, 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.

data Graph' block n e x where

Graph' is abstracted over the block type, so that we can build graphs of annotated blocks for example (Compiler.Hoopl.Dataflow needs this).

Constructors

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 

class NonLocal thing where

Gives access to the anchor points for nonlocal edges as well as the edges themselves

Methods

entryLabel

Arguments

:: thing C x 
-> Label

The label of a first node or block

successors

Arguments

:: thing e C 
-> [Label]

Gives control-flow successors

Instances

Constructing graphs

bodyGraph :: Body n -> Graph n C C

blockGraph :: NonLocal n => Block n e x -> Graph n e x

gUnitOO :: block n O O -> Graph' block n O O

gUnitOC :: block n O C -> Graph' block n O C

gUnitCO :: block n C O -> Graph' block n C O

gUnitCC :: NonLocal (block n) => block n C C -> Graph' block n C C

catGraphNodeOC :: NonLocal n => Graph n e O -> n O C -> Graph n e C

catGraphNodeOO :: Graph n e O -> n O O -> Graph n e O

catNodeCOGraph :: NonLocal n => n C O -> Graph n O x -> Graph n C x

catNodeOOGraph :: n O O -> Graph n O x -> Graph n O x

Splicing graphs

splice :: forall block n e a x. NonLocal (block n) => (forall e x. block n e O -> block n O x -> block n e x) -> Graph' block n e a -> Graph' block n a x -> Graph' block n e x

gSplice :: NonLocal n => Graph n e a -> Graph n a x -> Graph n e x

Maps

mapGraph :: (forall e x. n e x -> n' e x) -> Graph n e x -> Graph n' e x

Maps over all nodes in a graph.

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

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.

Folds

foldGraphNodes :: forall n a. (forall e x. n e x -> a -> a) -> forall e x. Graph n e x -> a -> a

Fold a function over every node in a graph. The fold function must be polymorphic in the shape of the nodes.

Extracting Labels

labelsDefined :: forall block n e x. NonLocal (block n) => Graph' block n e x -> LabelSet

labelsUsed :: forall block n e x. NonLocal (block n) => Graph' block n e x -> LabelSet

Depth-first traversals

postorder_dfs :: NonLocal (block n) => Graph' block n O x -> [block n C C]

Traversal: postorder_dfs returns a list of blocks reachable from the entry of enterable graph. The entry and exit are *not* included. The list has the following property:

Say a "back reference" exists if one of a block's control-flow successors precedes it in the output list

Then there are as few back references as possible

The output is suitable for use in a forward dataflow problem. For a backward problem, simply reverse the list. (postorder_dfs is sufficiently tricky to implement that one doesn't want to try and maintain both forward and backward versions.)

postorder_dfs_from :: (NonLocal block, LabelsPtr b) => LabelMap (block C C) -> b -> [block C C]

postorder_dfs_from_except :: forall block e. (NonLocal block, LabelsPtr e) => LabelMap (block C C) -> e -> LabelSet -> [block C C]

preorder_dfs :: NonLocal (block n) => Graph' block n O x -> [block n C C]

preorder_dfs_from_except :: forall block e. (NonLocal block, LabelsPtr e) => LabelMap (block C C) -> e -> LabelSet -> [block C C]

class LabelsPtr l where

Methods

targetLabels :: l -> [Label]

Shapes

data O

Used at the type level to indicate an "open" structure with a unique, unnamed control-flow edge flowing in or out. Fallthrough and concatenation are permitted at an open point.

Instances

IfThenElseable O 
type Fact O f = f 
type IndexedCO O a b = b 

data C

Used at the type level to indicate 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.

Instances

IfThenElseable C 
NonLocal n => LabelsPtr (n e C) 
type Fact C f = FactBase f 
type IndexedCO C a b = a 

data MaybeO ex t where

Maybe type indexed by open/closed

Constructors

JustO :: t -> MaybeO O t 
NothingO :: MaybeO C t 

Instances

data MaybeC ex t where

Maybe type indexed by closed/open

Constructors

JustC :: t -> MaybeC C t 
NothingC :: MaybeC O t 

Instances

type family IndexedCO ex a b :: *

Either type indexed by closed/open using type families

Instances

type IndexedCO C a b = a 
type IndexedCO O a b = b 

data Shape ex where

Dynamic shape value

Constructors

Closed :: Shape C 
Open :: Shape O 

Blocks

data Block n e x where

A sequence of nodes. May be any of four shapes (OO, OC, CO, CC). Open at the entry means single entry, mutatis mutandis for exit. A closedclosed block is a basic/ block and can't be extended further. Clients should avoid manipulating blocks and should stick to either nodes or graphs.

Constructors

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 

Instances

Predicates on Blocks

isEmptyBlock :: Block n e x -> Bool

Constructing blocks

blockCons :: n O O -> Block n O x -> Block n O x

blockSnoc :: Block n e O -> n O O -> Block n e O

blockJoinHead :: n C O -> Block n O x -> Block n C x

blockJoinTail :: Block n e O -> n O C -> Block n e C

blockJoin :: n C O -> Block n O O -> n O C -> Block n C C

blockJoinAny :: (MaybeC e (n C O), Block n O O, MaybeC x (n O C)) -> Block n e x

Convert a list of nodes to a block. The entry and exit node must or must not be present depending on the shape of the block.

blockAppend :: Block n e O -> Block n O x -> Block n e x

Deconstructing blocks

firstNode :: Block n C x -> n C O

lastNode :: Block n x C -> n O C

endNodes :: Block n C C -> (n C O, n O C)

blockSplitHead :: Block n C x -> (n C O, Block n O x)

blockSplitTail :: Block n e C -> (Block n e O, n O C)

blockSplit :: Block n C C -> (n C O, Block n O O, n O C)

Split a closed block into its entry node, open middle block, and exit node.

blockSplitAny :: Block n e x -> (MaybeC e (n C O), Block n O O, MaybeC x (n O C))

Modifying blocks

replaceFirstNode :: Block n C x -> n C O -> Block n C x

replaceLastNode :: Block n x C -> n O C -> Block n x C

Converting to and from lists

blockToList :: Block n O O -> [n O O]

blockFromList :: [n O O] -> Block n O O

Maps and folds

mapBlock :: (forall e x. n e x -> n' e x) -> Block n e x -> Block n' e x

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

A strict mapBlock

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

map over a block, with different functions to apply to first nodes, middle nodes and last nodes respectively. The map is strict.

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

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

Fold a function over every node in a block, forward or backward. The fold function must be polymorphic in the shape of the nodes.

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

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

Biasing

frontBiasBlock :: Block n e x -> Block n e x

A block is "front biased" if the left child of every concatenation operation is a node, not a general block; a front-biased block is analogous to an ordinary list. If a block is front-biased, then its nodes can be traversed from front to back without general recusion; tail recursion suffices. Not all shapes can be front-biased; a closed/open block is inherently back-biased.

backBiasBlock :: Block n e x -> Block n e x

A block is "back biased" if the right child of every concatenation operation is a node, not a general block; a back-biased block is analogous to a snoc-list. If a block is back-biased, then its nodes can be traversed from back to back without general recusion; tail recursion suffices. Not all shapes can be back-biased; an open/closed block is inherently front-biased.

data AGraph n e x

The type of abstract graphs. Offers extra "smart constructors" that may consume fresh labels during construction.

graphOfAGraph :: AGraph n e x -> forall m. UniqueMonad m => m (Graph n e x)

Take an abstract AGraph and make a concrete (if monadic) Graph.

aGraphOfGraph :: Graph n e x -> AGraph n e x

Take a graph and make it abstract.

(<*>) :: (GraphRep g, NonLocal n) => g n e O -> g n O x -> g n e x infixl 3

Concatenate two graphs; control flows from left to right.

(|*><*|) :: (GraphRep g, NonLocal n) => g n e C -> g n C x -> g n e x infixl 2

Splice together two graphs at a closed point; nothing is known about control flow.

catGraphs :: (GraphRep g, NonLocal n) => [g n O O] -> g n O O

Conveniently concatenate a sequence of open/open graphs using <*>.

addEntrySeq :: NonLocal n => AGraph n O C -> AGraph n C x -> AGraph n O x

Deprecated: use |*><*| instead

addExitSeq :: NonLocal n => AGraph n e C -> AGraph n C O -> AGraph n e O

Deprecated: use |*><*| instead

addBlocks :: HooplNode n => AGraph n e x -> AGraph n C C -> AGraph n e x

Extend an existing AGraph with extra basic blocks "out of line". No control flow is implied. Simon PJ should give example use case.

unionBlocks :: NonLocal n => AGraph n C C -> AGraph n C C -> AGraph n C C

Deprecated: use |*><*| instead

emptyGraph :: GraphRep g => g n O O

An empty graph that is open at entry and exit. It is the left and right identity of <*>.

emptyClosedGraph :: GraphRep g => g n C C

An empty graph that is closed at entry and exit. It is the left and right identity of |*><*|.

withFresh :: Uniques u => (u -> AGraph n e x) -> AGraph n e x

mkFirst :: GraphRep g => n C O -> g n C O

Create a graph from a first node

mkMiddle :: GraphRep g => n O O -> g n O O

Create a graph from a middle node

mkMiddles :: (GraphRep g, NonLocal n) => [n O O] -> g n O O

Conveniently concatenate a sequence of middle nodes to form an open/open graph.

mkLast :: GraphRep g => n O C -> g n O C

Create a graph from a last node

mkBranch :: (GraphRep g, HooplNode n) => Label -> g n O C

Create a graph that branches to a label

mkLabel :: (GraphRep g, HooplNode n) => Label -> g n C O

Create a graph that defines a label

mkWhileDo

Arguments

:: HooplNode n 
=> (Label -> Label -> AGraph n O C)

loop condition

-> AGraph n O O

body of the loop

-> AGraph n O O

the final while loop

class IfThenElseable x where

Methods

mkIfThenElse

Arguments

:: HooplNode n 
=> (Label -> Label -> AGraph n O C)

branch condition

-> AGraph n O x

code in the "then" branch

-> AGraph n O x

code in the "else" branch

-> AGraph n O x

resulting if-then-else construct

Translate a high-level if-then-else construct into an AGraph. The condition takes as arguments labels on the true-false branch and returns a single-entry, two-exit graph which exits to the two labels.

mkEntry :: GraphRep g => Block n O C -> g n O C

Create a graph containing only an entry sequence

mkExit :: GraphRep g => Block n C O -> g n C O

Create a graph containing only an exit sequence

class NonLocal n => HooplNode n where

For some graph-construction operations and some optimizations, Hoopl must be able to create control-flow edges using a given node type n.

Methods

mkBranchNode :: Label -> n O C

Create a branch node, the source of a control-flow edge.

mkLabelNode :: Label -> n C O

Create a label node, the target (destination) of a control-flow edge.

Utilities for clients

firstXfer :: NonLocal n => (n C O -> f -> f) -> n C O -> FactBase f -> f

A utility function so that a transfer function for a first node can be given just a fact; we handle the lookup. This function is planned to be made obsolete by changes in the dataflow interface.

distributeXfer :: NonLocal n => DataflowLattice f -> (n O C -> f -> f) -> n O C -> f -> FactBase f

This utility function handles a common case in which a transfer function produces a single fact out of a last node, which is then distributed over the outgoing edges.

distributeFact :: NonLocal n => n O C -> f -> FactBase f

This utility function handles a common case in which a transfer function for a last node takes the incoming fact unchanged and simply distributes that fact over the outgoing edges.

distributeFactBwd :: NonLocal n => n C O -> f -> FactBase f

This utility function handles a common case in which a backward transfer function takes the incoming fact unchanged and tags it with the node's label.

successorFacts :: NonLocal n => n O C -> FactBase f -> [f]

List of (unlabelled) facts from the successors of a last node

joinFacts :: DataflowLattice f -> Label -> [f] -> f

Join a list of facts.

joinOutFacts :: NonLocal node => DataflowLattice f -> node O C -> FactBase f -> f

Deprecated: should be replaced by 'joinFacts lat l (successorFacts n f)'; as is, it uses the wrong Label

joinMaps :: Ord k => JoinFun v -> JoinFun (Map k v)

It's common to represent dataflow facts as a map from variables to some fact about the locations. For these maps, the join operation on the map can be expressed in terms of the join on each element of the codomain:

analyzeAndRewriteFwdBody :: forall m n f entries. (CheckpointMonad m, NonLocal n, LabelsPtr entries) => FwdPass m n f -> entries -> Body n -> FactBase f -> m (Body n, FactBase f)

Forward dataflow analysis and rewriting for the special case of a Body. A set of entry points must be supplied; blocks not reachable from the set are thrown away.

analyzeAndRewriteBwdBody :: forall m n f entries. (CheckpointMonad m, NonLocal n, LabelsPtr entries) => BwdPass m n f -> entries -> Body n -> FactBase f -> m (Body n, FactBase f)

Backward dataflow analysis and rewriting for the special case of a Body. A set of entry points must be supplied; blocks not reachable from the set are thrown away.

analyzeAndRewriteFwdOx :: forall m n f x. (CheckpointMonad m, NonLocal n) => FwdPass m n f -> Graph n O x -> f -> m (Graph n O x, FactBase f, MaybeO x f)

Forward dataflow analysis and rewriting for the special case of a graph open at the entry. This special case relieves the client from having to specify a type signature for NothingO, which beginners might find confusing and experts might find annoying.

analyzeAndRewriteBwdOx :: forall m n f x. (CheckpointMonad m, NonLocal n) => BwdPass m n f -> Graph n O x -> Fact x f -> m (Graph n O x, FactBase f, f)

Backward dataflow analysis and rewriting for the special case of a graph open at the entry. This special case relieves the client from having to specify a type signature for NothingO, which beginners might find confusing and experts might find annoying.

class IsSet set where

Associated Types

type ElemOf set

Methods

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

setFold :: (ElemOf set -> b -> b) -> b -> set -> b

setElems :: set -> [ElemOf set]

setFromList :: [ElemOf set] -> set

setInsertList :: IsSet set => [ElemOf set] -> set -> set

setDeleteList :: IsSet set => [ElemOf set] -> set -> set

setUnions :: IsSet set => [set] -> set

class IsMap map where

Associated Types

type KeyOf map

Methods

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

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

mapFold :: (a -> b -> b) -> b -> map a -> b

mapFoldWithKey :: (KeyOf map -> a -> b -> b) -> b -> map a -> b

mapFilter :: (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

mapInsertList :: IsMap map => [(KeyOf map, a)] -> map a -> map a

mapDeleteList :: IsMap map => [KeyOf map] -> map a -> map a

mapUnions :: IsMap map => [map a] -> map a

class Monad m => CheckpointMonad m where

Obeys the following law: for all m do { s <- checkpoint; m; restart s } == return ()

Associated Types

type Checkpoint m

Methods

checkpoint :: m (Checkpoint m)

restart :: Checkpoint m -> m ()

data DataflowLattice a

A transfer function might want to use the logging flag to control debugging, as in for example, it updates just one element in a big finite map. We don't want Hoopl to show the whole fact, and only the transfer function knows exactly what changed.

Constructors

DataflowLattice 

Fields

fact_name :: String
 
fact_bot :: a
 
fact_join :: JoinFun a
 

type JoinFun a = Label -> OldFact a -> NewFact a -> (ChangeFlag, a)

newtype OldFact a

Constructors

OldFact a 

newtype NewFact a

Constructors

NewFact a 

type family Fact x f :: *

Instances

type Fact C f = FactBase f 
type Fact O f = f 

mkFactBase :: forall f. DataflowLattice f -> [(Label, f)] -> FactBase f

mkFactBase creates a FactBase from a list of (Label, fact) pairs. If the same label appears more than once, the relevant facts are joined.

data ChangeFlag

Constructors

NoChange 
SomeChange 

data FwdPass m n f

Constructors

FwdPass 

newtype FwdTransfer n f

Constructors

FwdTransfer3 

Fields

getFTransfer3 :: (n C O -> f -> f, n O O -> f -> f, n O C -> f -> FactBase f)
 

mkFTransfer :: (forall e x. n e x -> f -> Fact x f) -> FwdTransfer n f

mkFTransfer3 :: (n C O -> f -> f) -> (n O O -> f -> f) -> (n O C -> f -> FactBase f) -> FwdTransfer n f

newtype FwdRewrite m n f

Constructors

FwdRewrite3 

Fields

getFRewrite3 :: (n C O -> f -> m (Maybe (Graph n C O, FwdRewrite m n f)), n O O -> f -> m (Maybe (Graph n O O, FwdRewrite m n f)), n O C -> f -> m (Maybe (Graph n O C, FwdRewrite m n f)))
 

mkFRewrite :: FuelMonad m => (forall e x. n e x -> f -> m (Maybe (Graph n e x))) -> FwdRewrite m n f

Functions passed to mkFRewrite should not be aware of the fuel supply. The result returned by mkFRewrite respects fuel.

mkFRewrite3 :: forall m n f. FuelMonad m => (n C O -> f -> m (Maybe (Graph n C O))) -> (n O O -> f -> m (Maybe (Graph n O O))) -> (n O C -> f -> m (Maybe (Graph n O C))) -> FwdRewrite m n f

Functions passed to mkFRewrite3 should not be aware of the fuel supply. The result returned by mkFRewrite3 respects fuel.

wrapFR

Arguments

:: (forall e x. (n e x -> f -> m (Maybe (Graph n e x, FwdRewrite m n f))) -> n' e x -> f' -> m' (Maybe (Graph n' e x, FwdRewrite m' n' f')))

This argument may assume that any function passed to it respects fuel, and it must return a result that respects fuel.

-> FwdRewrite m n f 
-> FwdRewrite m' n' f' 

wrapFR2

Arguments

:: (forall e x. (n1 e x -> f1 -> m1 (Maybe (Graph n1 e x, FwdRewrite m1 n1 f1))) -> (n2 e x -> f2 -> m2 (Maybe (Graph n2 e x, FwdRewrite m2 n2 f2))) -> n3 e x -> f3 -> m3 (Maybe (Graph n3 e x, FwdRewrite m3 n3 f3)))

This argument may assume that any function passed to it respects fuel, and it must return a result that respects fuel.

-> FwdRewrite m1 n1 f1 
-> FwdRewrite m2 n2 f2 
-> FwdRewrite m3 n3 f3 

data BwdPass m n f

Constructors

BwdPass 

newtype BwdTransfer n f

Constructors

BwdTransfer3 

Fields

getBTransfer3 :: (n C O -> f -> f, n O O -> f -> f, n O C -> FactBase f -> f)
 

mkBTransfer :: (forall e x. n e x -> Fact x f -> f) -> BwdTransfer n f

mkBTransfer3 :: (n C O -> f -> f) -> (n O O -> f -> f) -> (n O C -> FactBase f -> f) -> BwdTransfer n f

wrapBR

Arguments

:: (forall e x. Shape x -> (n e x -> Fact x f -> m (Maybe (Graph n e x, BwdRewrite m n f))) -> n' e x -> Fact x f' -> m' (Maybe (Graph n' e x, BwdRewrite m' n' f')))

This argument may assume that any function passed to it respects fuel, and it must return a result that respects fuel.

-> BwdRewrite m n f 
-> BwdRewrite m' n' f' 

wrapBR2

Arguments

:: (forall e x. Shape x -> (n1 e x -> Fact x f1 -> m1 (Maybe (Graph n1 e x, BwdRewrite m1 n1 f1))) -> (n2 e x -> Fact x f2 -> m2 (Maybe (Graph n2 e x, BwdRewrite m2 n2 f2))) -> n3 e x -> Fact x f3 -> m3 (Maybe (Graph n3 e x, BwdRewrite m3 n3 f3)))

This argument may assume that any function passed to it respects fuel, and it must return a result that respects fuel.

-> BwdRewrite m1 n1 f1 
-> BwdRewrite m2 n2 f2 
-> BwdRewrite m3 n3 f3 

newtype BwdRewrite m n f

Constructors

BwdRewrite3 

Fields

getBRewrite3 :: (n C O -> f -> m (Maybe (Graph n C O, BwdRewrite m n f)), n O O -> f -> m (Maybe (Graph n O O, BwdRewrite m n f)), n O C -> FactBase f -> m (Maybe (Graph n O C, BwdRewrite m n f)))
 

mkBRewrite :: FuelMonad m => (forall e x. n e x -> Fact x f -> m (Maybe (Graph n e x))) -> BwdRewrite m n f

Functions passed to mkBRewrite should not be aware of the fuel supply. The result returned by mkBRewrite respects fuel.

mkBRewrite3 :: forall m n f. FuelMonad m => (n C O -> f -> m (Maybe (Graph n C O))) -> (n O O -> f -> m (Maybe (Graph n O O))) -> (n O C -> FactBase f -> m (Maybe (Graph n O C))) -> BwdRewrite m n f

Functions passed to mkBRewrite3 should not be aware of the fuel supply. The result returned by mkBRewrite3 respects fuel.

analyzeAndRewriteFwd :: forall m n f e x entries. (CheckpointMonad m, NonLocal n, LabelsPtr entries) => FwdPass m n f -> MaybeC e entries -> Graph n e x -> Fact e f -> m (Graph n e x, FactBase f, MaybeO x f)

if the graph being analyzed is open at the entry, there must be no other entry point, or all goes horribly wrong...

analyzeAndRewriteBwd :: (CheckpointMonad m, NonLocal n, LabelsPtr entries) => BwdPass m n f -> MaybeC e entries -> Graph n e x -> Fact x f -> m (Graph n e x, FactBase f, MaybeO e f)

if the graph being analyzed is open at the exit, I don't quite understand the implications of possible other exits

Respecting Fuel

A value of type FwdRewrite or BwdRewrite respects fuel if any function contained within the value satisfies the following properties:

  • When fuel is exhausted, it always returns Nothing.
  • When it returns Just g rw, it consumes exactly one unit of fuel, and new rewrite rw also respects fuel.

Provided that functions passed to mkFRewrite, mkFRewrite3, mkBRewrite, and mkBRewrite3 are not aware of the fuel supply, the results respect fuel.

It is an unchecked run-time error for the argument passed to wrapFR, wrapFR2, wrapBR, or warpBR2 to return a function that does not respect fuel.

data LabelMap v

Instances

IsMap LabelMap 
Eq v => Eq (LabelMap v) 
Ord v => Ord (LabelMap v) 
Show v => Show (LabelMap v) 
type KeyOf LabelMap = Label 

type FactBase f = LabelMap f

data Pointed t b a where

Adds top, bottom, or both to help form a lattice

The type parameters t and b are used to say whether top and bottom elements have been added. The analogy with Block is nearly exact:

  • A Block is closed at the entry if and only if it has a first node; a Pointed is closed at the top if and only if it has a top element.
  • A Block is closed at the exit if and only if it has a last node; a Pointed is closed at the bottom if and only if it has a bottom element.

We thus have four possible types, of which three are interesting:

Pointed C C a
Type a extended with both top and bottom elements.
Pointed C O a
Type a extended with a top element only. (Presumably a comes equipped with a bottom element of its own.)
Pointed O C a
Type a extended with a bottom element only.
Pointed O O a
Isomorphic to a, and therefore not interesting.

The advantage of all this GADT-ishness is that the constructors Bot, Top, and PElem can all be used polymorphically.

A 'Pointed t b' type is an instance of Functor and Show.

Constructors

Bot :: Pointed t C a 
PElem :: a -> Pointed t b a 
Top :: Pointed C b a 

Instances

Functor (Pointed t b) 
Eq a => Eq (Pointed t b a) 
Ord a => Ord (Pointed t b a) 
Show a => Show (Pointed t b a) 

addPoints :: String -> JoinFun a -> DataflowLattice (Pointed t C a)

Given a join function and a name, creates a semi lattice by adding a bottom element, and possibly a top element also. A specialized version of addPoints'.

addPoints' :: forall a t. String -> (Label -> OldFact a -> NewFact a -> (ChangeFlag, Pointed t C a)) -> DataflowLattice (Pointed t C a)

A more general case for creating a new lattice

addTop :: DataflowLattice a -> DataflowLattice (WithTop a)

Given a join function and a name, creates a semi lattice by adding a top element but no bottom element. Caller must supply the bottom element.

addTop' :: forall a. String -> a -> (Label -> OldFact a -> NewFact a -> (ChangeFlag, WithTop a)) -> DataflowLattice (WithTop a)

A more general case for creating a new lattice

extendJoinDomain :: forall a. (Label -> OldFact a -> NewFact a -> (ChangeFlag, WithTop a)) -> JoinFun (WithTop a)

type WithTop a = Pointed C O a

Type a with a top element adjoined

type WithBot a = Pointed O C a

Type a with a bottom element adjoined

type WithTopAndBot a = Pointed C C a

Type a with top and bottom elements adjoined

thenFwdRw :: forall m n f. Monad m => FwdRewrite m n f -> FwdRewrite m n f -> FwdRewrite m n f

deepFwdRw3 :: FuelMonad m => (n C O -> f -> m (Maybe (Graph n C O))) -> (n O O -> f -> m (Maybe (Graph n O O))) -> (n O C -> f -> m (Maybe (Graph n O C))) -> FwdRewrite m n f

deepFwdRw :: FuelMonad m => (forall e x. n e x -> f -> m (Maybe (Graph n e x))) -> FwdRewrite m n f

iterFwdRw :: forall m n f. Monad m => FwdRewrite m n f -> FwdRewrite m n f

thenBwdRw :: forall m n f. Monad m => BwdRewrite m n f -> BwdRewrite m n f -> BwdRewrite m n f

deepBwdRw3 :: FuelMonad m => (n C O -> f -> m (Maybe (Graph n C O))) -> (n O O -> f -> m (Maybe (Graph n O O))) -> (n O C -> FactBase f -> m (Maybe (Graph n O C))) -> BwdRewrite m n f

deepBwdRw :: FuelMonad m => (forall e x. n e x -> Fact x f -> m (Maybe (Graph n e x))) -> BwdRewrite m n f

iterBwdRw :: forall m n f. Monad m => BwdRewrite m n f -> BwdRewrite m n f

pairFwd :: forall m n f f'. Monad m => FwdPass m n f -> FwdPass m n f' -> FwdPass m n (f, f')

pairBwd :: forall m n f f'. Monad m => BwdPass m n f -> BwdPass m n f' -> BwdPass m n (f, f')

pairLattice :: forall f f'. DataflowLattice f -> DataflowLattice f' -> DataflowLattice (f, f')

type Fuel = Int

fuelRemaining :: FuelMonad m => m Fuel

Find out how much fuel remains after a computation. Can be subtracted from initial fuel to get total consumption.

withFuel :: FuelMonad m => Maybe a -> m (Maybe a)

class Monad m => FuelMonad m where

Methods

getFuel :: m Fuel

setFuel :: Fuel -> m ()

class FuelMonadT fm where

Methods

runWithFuel :: (Monad m, FuelMonad (fm m)) => Fuel -> fm m a -> m a

liftFuel :: (Monad m, FuelMonad (fm m)) => m a -> fm m a

type Unique = Int

data UniqueMap v

Instances

IsMap UniqueMap 
Eq v => Eq (UniqueMap v) 
Ord v => Ord (UniqueMap v) 
Show v => Show (UniqueMap v) 
type KeyOf UniqueMap = Unique 

type TraceFn = forall a. String -> a -> a

debugFwdJoins :: forall m n f. Show f => TraceFn -> ChangePred -> FwdPass m n f -> FwdPass m n f

Debugging combinators: Each combinator takes a dataflow pass and produces a dataflow pass that can output debugging messages. You provide the function, we call it with the applicable message.

The most common use case is probably to:

  1. import Trace
  2. pass trace as the 1st argument to the debug combinator
  3. pass 'const true' as the 2nd argument to the debug combinator

There are two kinds of debugging messages for a join, depending on whether the join is higher in the lattice than the old fact: 1. If the join is higher, we show: + JoinL: f1 join f2 = f' where: + indicates a change L is the label where the join takes place f1 is the old fact at the label f2 is the new fact we are joining to f1 f' is the result of the join 2. _ JoinL: f2 <= f1 where: _ indicates no change L is the label where the join takes place f1 is the old fact at the label (which remains unchanged) f2 is the new fact we joined with f1

debugBwdJoins :: forall m n f. Show f => TraceFn -> ChangePred -> BwdPass m n f -> BwdPass m n f

debugFwdTransfers :: forall m n f. Show f => TraceFn -> ShowN n -> FPred n f -> FwdPass m n f -> FwdPass m n f

debugBwdTransfers :: forall m n f. Show f => TraceFn -> ShowN n -> BPred n f -> BwdPass m n f -> BwdPass m n f

showGraph :: forall n e x. NonLocal n => Showing n -> Graph n e x -> String