Packages

abstract class TailCalls extends SubComponent with Transform

Perform tail recursive call elimination.

Source
TailCalls.scala
Version

1.0

Linear Supertypes
Transform, SubComponent, AnyRef, Any
Known Subclasses
tailCalls
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. TailCalls
  2. Transform
  3. SubComponent
  4. AnyRef
  5. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. All

Instance Constructors

  1. new TailCalls()

Type Members

  1. abstract class StdPhase extends GlobalPhase

    A standard phase template

    A standard phase template

    Definition Classes
    SubComponent
  2. class Phase extends StdPhase

    The phase defined by this transform

  3. class TailCallElimination extends Global.Transformer

    A Tail Call Transformer

    A Tail Call Transformer

    Version

    1.1 What it does: Finds method calls in tail-position and replaces them with jumps. A call is in a tail-position if it is the last instruction to be executed in the body of a method. This is done by recursing over the trees that may contain calls in tail-position (trees that can't contain such calls are not transformed). However, they are not that many. Self-recursive calls in tail-position are replaced by jumps to a label at the beginning of the method. As the JVM provides no way to jump from a method to another one, non-recursive calls in tail-position are not optimized. A method call is self-recursive if it calls the current method and the method is final (otherwise, it could be a call to an overridden method in a subclass). Furthermore, if the method has @specialized annotated type parameters, the recursive call must contain these parameters as type arguments. Recursive calls on a different instance are optimized. Since 'this' is not a local variable, a dummy local val is added and used as a label parameter. The backend knows to load the corresponding argument in the 'this' (local at index 0). This dummy local is never used and should be cleaned up by dead code elimination (when enabled). This phase has been moved before pattern matching to catch more of the common cases of tail recursive functions. This means that more cases should be taken into account (like nested function, and pattern cases). If a method contains self-recursive calls, a label is added to at the beginning of its body and the calls are replaced by jumps to that label. Assumes: Uncurry has been run already, and no multiple parameter lists exist.

  4. class TailPosLabelsTraverser extends Global.Traverser

Abstract Value Members

  1. abstract val global: Global

    The global environment; overridden by instantiation in Global.

    The global environment; overridden by instantiation in Global.

    Definition Classes
    SubComponent
  2. abstract val runsAfter: List[String]

    Names of phases that must run before this phase.

    Names of phases that must run before this phase.

    Definition Classes
    SubComponent
  3. abstract val runsRightAfter: Option[String]

    Name of the phase that this phase must follow immediately.

    Name of the phase that this phase must follow immediately.

    Definition Classes
    SubComponent

Concrete Value Members

  1. final def afterOwnPhase[T](op: ⇒ T): T
    Definition Classes
    SubComponent
    Annotations
    @inline()
  2. final def beforeOwnPhase[T](op: ⇒ T): T
    Definition Classes
    SubComponent
    Annotations
    @inline()
  3. def enabled: Boolean

    Is this component enabled? Default is true.

    Is this component enabled? Default is true.

    Definition Classes
    SubComponent
  4. def hashCode(): Int

    SubComponent are added to a HashSet and two phases are the same if they have the same name

    SubComponent are added to a HashSet and two phases are the same if they have the same name

    Definition Classes
    SubComponent → AnyRef → Any
  5. val initial: Boolean

    True if this phase runs before all other phases.

    True if this phase runs before all other phases. Usually, parser.

    Definition Classes
    SubComponent
  6. val internal: Boolean

    True if this phase is not provided by a plug-in.

    True if this phase is not provided by a plug-in.

    Definition Classes
    SubComponent
  7. def newPhase(prev: nsc.Phase): StdPhase

    Create a new phase which applies transformer

    Create a new phase which applies transformer

    Definition Classes
    TailCalls → Transform → SubComponent
  8. def newTransformer(unit: Global.CompilationUnit): Global.Transformer

    The transformer factory

    The transformer factory

    Definition Classes
    TailCalls → Transform
  9. def ownPhase: nsc.Phase

    The phase corresponding to this subcomponent in the current compiler run

    The phase corresponding to this subcomponent in the current compiler run

    Definition Classes
    SubComponent
  10. val phaseName: String

    The name of the phase

    The name of the phase

    Definition Classes
    TailCalls → SubComponent
  11. def phaseNewFlags: Long

    New flags defined by the phase which are not valid before

    New flags defined by the phase which are not valid before

    Definition Classes
    SubComponent
  12. def phaseNextFlags: Long

    New flags defined by the phase which are not valid until immediately after it

    New flags defined by the phase which are not valid until immediately after it

    Definition Classes
    SubComponent
  13. val requires: List[String]

    Names of phases required by this component.

    Names of phases required by this component. Default is Nil.

    Definition Classes
    SubComponent
  14. val runsBefore: List[String]

    Names of phases that must run after this phase.

    Names of phases that must run after this phase. Default is Nil.

    Definition Classes
    SubComponent
  15. val terminal: Boolean

    True if this phase runs after all other phases.

    True if this phase runs after all other phases. Usually, terminal.

    Definition Classes
    SubComponent