hoopl-3.9.0.0: A library to support dataflow analysis and optimization

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Compiler.Hoopl.Internals

Contents

Synopsis

Shapes

data O Source

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

data C Source

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

data MaybeO ex t whereSource

Maybe type indexed by open/closed

Constructors

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

Instances

data MaybeC ex t whereSource

Maybe type indexed by closed/open

Constructors

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

Instances

type family IndexedCO ex a b :: *Source

Either type indexed by closed/open using type families

data Shape ex whereSource

Dynamic shape value

Constructors

Closed :: Shape C 
Open :: Shape O 

Blocks

data Block n e x whereSource

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

Constructing blocks

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

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

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

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

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

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

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 xSource

Deconstructing blocks

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

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

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

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

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

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

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))Source

Modifying blocks

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

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

Converting to and from lists

Maps and folds

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

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 xSource

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 xSource

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 aSource

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 bSource

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 aSource

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 bSource

Biasing

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

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 xSource

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.

Body

type Body n = LabelMap (Block n C C)Source

A (possibly empty) collection of closed/closed blocks

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

Body abstracted over block

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

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

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

Graph

type Graph = Graph' BlockSource

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 whereSource

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 whereSource

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

Methods

entryLabelSource

Arguments

:: thing C x 
-> Label

The label of a first node or block

successorsSource

Arguments

:: thing e C 
-> [Label]

Gives control-flow successors

Instances

Constructing graphs

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

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

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

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

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

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

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

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

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

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 xSource

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

Maps

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

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 xSource

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 -> aSource

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 -> LabelSetSource

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

Depth-first traversals

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

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]Source

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

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

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

class LabelsPtr l whereSource

Methods

targetLabels :: l -> [Label]Source

data LabelMap v Source

Instances

IsMap LabelMap 
Eq v => Eq (LabelMap v) 
Ord v => Ord (LabelMap v) 
Show v => Show (LabelMap v) 

data DataflowLattice a Source

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)Source

newtype OldFact a Source

Constructors

OldFact a 

newtype NewFact a Source

Constructors

NewFact a 

type family Fact x f :: *Source

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

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 FwdPass m n f Source

Constructors

FwdPass 

newtype FwdTransfer n f Source

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 fSource

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

newtype FwdRewrite m n f Source

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 fSource

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 fSource

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

wrapFRSource

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' 

wrapFR2Source

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 Source

Constructors

BwdPass 

newtype BwdTransfer n f Source

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 fSource

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

wrapBRSource

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' 

wrapBR2Source

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 Source

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 fSource

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 fSource

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)Source

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)Source

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.