Futhark.IR.Prop.Aliases

The IR tracks aliases, mostly to ensure the soundness of in-place updates, but it can also be used for other things (such as memory optimisations). This module contains the raw building blocks for determining the aliases of the values produced by expressions. It also contains some building blocks for inspecting consumption.

One important caveat is that all aliases computed here are local. Thus, they do not take aliases-of-aliases into account. See Futhark.Analysis.Alias if this is not what you want.

Documentation

subExpAliases :: SubExp -> Names

The aliases of a subexpression.

expAliases :: Aliased rep => [PatElem dec] -> Exp rep -> [Names]

The aliases of an expression, one for each pattern element.

The pattern is important because some aliasing might be through variables that are no longer in scope (consider the aliases for a body that returns the same value multiple times).

patAliases :: AliasesOf dec => Pat dec -> [Names]

The aliases of each pattern element.

lookupAliases :: AliasesOf (LetDec rep) => VName -> Scope rep -> Names

Also includes the name itself.

class (ASTRep rep, AliasedOp (Op rep), AliasesOf (LetDec rep)) => Aliased rep where

The class of representations that contain aliasing information.

Methods

bodyAliases :: Body rep -> [Names]

The aliases of the body results. Note that this includes names bound in the body!

consumedInBody :: Body rep -> Names

The variables consumed in the body.

Instances

(ASTRep rep, AliasedOp (OpC rep (Aliases rep))) => Aliased (Aliases rep)

Defined in Futhark.IR.Aliases

Methods

bodyAliases :: Body (Aliases rep) -> [Names]

consumedInBody :: Body (Aliases rep) -> Names

Informing rep => Aliased (Wise rep)

Defined in Futhark.Optimise.Simplify.Rep

Methods

bodyAliases :: Body (Wise rep) -> [Names]

consumedInBody :: Body (Wise rep) -> Names

class AliasesOf a where

Something that contains alias information.

Methods

aliasesOf :: a -> Names

The alias of the argument element.

Instances

AliasesOf Names

Defined in Futhark.IR.Prop.Aliases

Methods

aliasesOf :: Names -> Names

AliasesOf dec => AliasesOf (PatElem dec)

Defined in Futhark.IR.Prop.Aliases

Methods

aliasesOf :: PatElem dec -> Names

AliasesOf (VarAliases, dec)

Defined in Futhark.IR.Aliases

Methods

aliasesOf :: (VarAliases, dec) -> Names

AliasesOf (VarWisdom, dec)

Defined in Futhark.Optimise.Simplify.Rep

Methods

aliasesOf :: (VarWisdom, dec) -> Names

Consumption

consumedInStm :: Aliased rep => Stm rep -> Names

The variables consumed in this statement.

consumedInExp :: Aliased rep => Exp rep -> Names

The variables consumed in this expression.

consumedByLambda :: Aliased rep => Lambda rep -> Names

The variables consumed by this lambda.

Extensibility

type AliasTable = Map VName Names

Pre-existing aliases for variables. Used to add transitive aliases.

class IsOp op => AliasedOp op where

The class of operations that can produce aliasing and consumption information.

Methods

opAliases :: op -> [Names]

consumedInOp :: op -> Names

Instances

AliasedOp SizeOp

Defined in Futhark.IR.GPU.Op

Methods

opAliases :: SizeOp -> [Names]

consumedInOp :: SizeOp -> Names

Aliased rep => AliasedOp (SOAC rep)

Defined in Futhark.IR.SOACS.SOAC

Methods

opAliases :: SOAC rep -> [Names]

consumedInOp :: SOAC rep -> Names

(Aliased rep, AliasedOp (op rep)) => AliasedOp (HostOp op rep)

Defined in Futhark.IR.GPU.Op

Methods

opAliases :: HostOp op rep -> [Names]

consumedInOp :: HostOp op rep -> Names

(Aliased rep, AliasedOp (op rep)) => AliasedOp (MCOp op rep)

Defined in Futhark.IR.MC.Op

Methods

opAliases :: MCOp op rep -> [Names]

consumedInOp :: MCOp op rep -> Names

AliasedOp (inner rep) => AliasedOp (MemOp inner rep)

Defined in Futhark.IR.Mem

Methods

opAliases :: MemOp inner rep -> [Names]

consumedInOp :: MemOp inner rep -> Names

AliasedOp (NoOp rep)

Defined in Futhark.IR.Prop.Aliases

Methods

opAliases :: NoOp rep -> [Names]

consumedInOp :: NoOp rep -> Names

(ASTConstraints lvl, Aliased rep) => AliasedOp (SegOp lvl rep)

Defined in Futhark.IR.SegOp

Methods

opAliases :: SegOp lvl rep -> [Names]

consumedInOp :: SegOp lvl rep -> Names