Add explicit boxing and unboxing instructions. Recall that the Lean to λ_pure compiler produces code without these instructions.

Assumptions:

• This transformation is applied before explicit RC instructions (inc, dec) are inserted.
• This transformation is applied before FnBody.case has been simplified and Alt.default is used. Reason: if there is no Alt.default branch, then we can decide whether x at FnBody.case x alts is an enumeration type by simply inspecting the CtorInfo values at alts.
• This transformation is applied before lower level optimizations are applied which use Expr.isShared, Expr.isTaggedPtr, and FnBody.set.
• This transformation is applied after reset and reuse instructions have been added. Reason: resetreuse.lean ignores box and unbox instructions.

def Lean.IR.ExplicitBoxing.mkBoxedName (n : Lake.Name) : Lake.Name

Equations

• Lean.IR.ExplicitBoxing.mkBoxedName n = Lean.Name.mkStr n "_boxed"

def Lean.IR.ExplicitBoxing.isBoxedName (name : Lake.Name) : Bool

Equations

• Lean.IR.ExplicitBoxing.isBoxedName name = match name with | Lean.Name.str pre "_boxed" => true | x => false

@[inline, reducible]

abbrev Lean.IR.ExplicitBoxing.N (α : Type) : Type

Equations

• Lean.IR.ExplicitBoxing.N = StateM Nat

def Lean.IR.ExplicitBoxing.requiresBoxedVersion (env : Lean.Environment) (decl : Lean.IR.Decl) : Bool

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def Lean.IR.ExplicitBoxing.mkBoxedVersionAux (decl : Lean.IR.Decl) : Lean.IR.ExplicitBoxing.N Lean.IR.Decl

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def Lean.IR.ExplicitBoxing.mkBoxedVersion (decl : Lean.IR.Decl) : Lean.IR.Decl

Equations

• Lean.IR.ExplicitBoxing.mkBoxedVersion decl = StateT.run' (Lean.IR.ExplicitBoxing.mkBoxedVersionAux decl) 1

def Lean.IR.ExplicitBoxing.addBoxedVersions (env : Lean.Environment) (decls : Array Lean.IR.Decl) : Array Lean.IR.Decl

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def Lean.IR.ExplicitBoxing.getScrutineeType (alts : Array Lean.IR.Alt) : Lean.IR.IRType

Infer scrutinee type using case alternatives. This can be done whenever alts does not contain an Alt.default _ value.

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def Lean.IR.ExplicitBoxing.eqvTypes (t₁ : Lean.IR.IRType) (t₂ : Lean.IR.IRType) : Bool

Equations

• Lean.IR.ExplicitBoxing.eqvTypes t₁ t₂ = (Lean.IR.IRType.isScalar t₁ == Lean.IR.IRType.isScalar t₂ && (!Lean.IR.IRType.isScalar t₁ || t₁ == t₂))

structure Lean.IR.ExplicitBoxing.BoxingContext : Type

• f : Lean.IR.FunId
• localCtx : Lean.IR.LocalContext
• resultType : Lean.IR.IRType
• decls : Array Lean.IR.Decl
• env : Lean.Environment

structure Lean.IR.ExplicitBoxing.BoxingState : Type

• nextIdx : Lean.IR.Index
• auxDecls : Array Lean.IR.Decl

  We create auxiliary declarations when boxing constant and literals. The idea is to avoid code such as

  let x1 := Uint64.inhabited;
  let x2 := box x1;
  ...
  

  We currently do not cache these declarations in an environment extension, but we use auxDeclCache to avoid creating equivalent auxiliary declarations more than once when processing the same IR declaration.

• auxDeclCache : Lean.AssocList Lean.IR.FnBody Lean.IR.Expr
• nextAuxId : Nat

@[inline, reducible]

abbrev Lean.IR.ExplicitBoxing.M (α : Type) : Type

Equations

• Lean.IR.ExplicitBoxing.M = ReaderT Lean.IR.ExplicitBoxing.BoxingContext (StateT Lean.IR.ExplicitBoxing.BoxingState Id)

def Lean.IR.ExplicitBoxing.getEnv : Lean.IR.ExplicitBoxing.M Lean.Environment

Equations

• Lean.IR.ExplicitBoxing.getEnv = Lean.IR.ExplicitBoxing.BoxingContext.env <$> read

def Lean.IR.ExplicitBoxing.getLocalContext : Lean.IR.ExplicitBoxing.M Lean.IR.LocalContext

Equations

• Lean.IR.ExplicitBoxing.getLocalContext = Lean.IR.ExplicitBoxing.BoxingContext.localCtx <$> read

def Lean.IR.ExplicitBoxing.getResultType : Lean.IR.ExplicitBoxing.M Lean.IR.IRType

Equations

• Lean.IR.ExplicitBoxing.getResultType = Lean.IR.ExplicitBoxing.BoxingContext.resultType <$> read

def Lean.IR.ExplicitBoxing.getVarType (x : Lean.IR.VarId) : Lean.IR.ExplicitBoxing.M Lean.IR.IRType

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def Lean.IR.ExplicitBoxing.getJPParams (j : Lean.IR.JoinPointId) : Lean.IR.ExplicitBoxing.M (Array Lean.IR.Param)

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def Lean.IR.ExplicitBoxing.getDecl (fid : Lean.IR.FunId) : Lean.IR.ExplicitBoxing.M Lean.IR.Decl

Equations

• Lean.IR.ExplicitBoxing.getDecl fid = do let ctx ← read match Lean.IR.findEnvDecl' ctx.env fid ctx.decls with | some decl => pure decl | none => pure default

@[inline]

def Lean.IR.ExplicitBoxing.withParams {α : Type} (xs : Array Lean.IR.Param) (k : Lean.IR.ExplicitBoxing.M α) : Lean.IR.ExplicitBoxing.M α

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@[inline]

def Lean.IR.ExplicitBoxing.withVDecl {α : Type} (x : Lean.IR.VarId) (ty : Lean.IR.IRType) (v : Lean.IR.Expr) (k : Lean.IR.ExplicitBoxing.M α) : Lean.IR.ExplicitBoxing.M α

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@[inline]

def Lean.IR.ExplicitBoxing.withJDecl {α : Type} (j : Lean.IR.JoinPointId) (xs : Array Lean.IR.Param) (v : Lean.IR.FnBody) (k : Lean.IR.ExplicitBoxing.M α) : Lean.IR.ExplicitBoxing.M α

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def Lean.IR.ExplicitBoxing.mkCast (x : Lean.IR.VarId) (xType : Lean.IR.IRType) (expectedType : Lean.IR.IRType) : Lean.IR.ExplicitBoxing.M Lean.IR.Expr

Auxiliary function used by castVarIfNeeded. It is used when the expected type does not match xType. If xType is scalar, then we need to "box" it. Otherwise, we need to "unbox" it.

Equations

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@[inline]

def Lean.IR.ExplicitBoxing.castVarIfNeeded (x : Lean.IR.VarId) (expected : Lean.IR.IRType) (k : Lean.IR.VarId → Lean.IR.ExplicitBoxing.M Lean.IR.FnBody) : Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

Equations

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@[inline]

def Lean.IR.ExplicitBoxing.castArgIfNeeded (x : Lean.IR.Arg) (expected : Lean.IR.IRType) (k : Lean.IR.Arg → Lean.IR.ExplicitBoxing.M Lean.IR.FnBody) : Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

Equations

• Lean.IR.ExplicitBoxing.castArgIfNeeded x expected k = match x with | Lean.IR.Arg.var x => Lean.IR.ExplicitBoxing.castVarIfNeeded x expected fun x => k (Lean.IR.Arg.var x) | x => k x

def Lean.IR.ExplicitBoxing.castArgsIfNeededAux (xs : Array Lean.IR.Arg) (typeFromIdx : Nat → Lean.IR.IRType) : Lean.IR.ExplicitBoxing.M (Array Lean.IR.Arg × Array Lean.IR.FnBody)

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@[inline]

def Lean.IR.ExplicitBoxing.castArgsIfNeeded (xs : Array Lean.IR.Arg) (ps : Array Lean.IR.Param) (k : Array Lean.IR.Arg → Lean.IR.ExplicitBoxing.M Lean.IR.FnBody) : Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

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@[inline]

def Lean.IR.ExplicitBoxing.boxArgsIfNeeded (xs : Array Lean.IR.Arg) (k : Array Lean.IR.Arg → Lean.IR.ExplicitBoxing.M Lean.IR.FnBody) : Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

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def Lean.IR.ExplicitBoxing.unboxResultIfNeeded (x : Lean.IR.VarId) (ty : Lean.IR.IRType) (e : Lean.IR.Expr) (b : Lean.IR.FnBody) : Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

Equations

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def Lean.IR.ExplicitBoxing.castResultIfNeeded (x : Lean.IR.VarId) (ty : Lean.IR.IRType) (e : Lean.IR.Expr) (eType : Lean.IR.IRType) (b : Lean.IR.FnBody) : Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

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def Lean.IR.ExplicitBoxing.visitVDeclExpr (x : Lean.IR.VarId) (ty : Lean.IR.IRType) (e : Lean.IR.Expr) (b : Lean.IR.FnBody) : Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

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partial def Lean.IR.ExplicitBoxing.visitFnBody : Lean.IR.FnBody → Lean.IR.ExplicitBoxing.M Lean.IR.FnBody

def Lean.IR.ExplicitBoxing.run (env : Lean.Environment) (decls : Array Lean.IR.Decl) : Array Lean.IR.Decl

Equations

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def Lean.IR.explicitBoxing (decls : Array Lean.IR.Decl) : Lean.IR.CompilerM (Array Lean.IR.Decl)

Equations

• Lean.IR.explicitBoxing decls = do let env ← Lean.IR.getEnv pure (Lean.IR.ExplicitBoxing.run env decls)