abstract class TailCalls extends SubComponent with Transform
Perform tail recursive call elimination.
- Source
- TailCalls.scala
- Version
1.0
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Instance Constructors
- new TailCalls()
Type Members
-
abstract
class
StdPhase
extends GlobalPhase
A standard phase template
A standard phase template
- Definition Classes
- SubComponent
-
class
Phase
extends StdPhase
The phase defined by this transform
-
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 type parameters, the 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:
Uncurryhas been run already, and no multiple parameter lists exist.
- class TailPosLabelsTraverser extends Global.Traverser
Abstract Value Members
-
abstract
val
global: Global
The global environment; overridden by instantiation in Global.
The global environment; overridden by instantiation in Global.
- Definition Classes
- SubComponent
-
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
-
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
-
final
def
!=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
final
def
##(): Int
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- def ->[B](y: B): (TailCalls, B)
-
final
def
==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
final
def
afterOwnPhase[T](op: ⇒ T): T
- Definition Classes
- SubComponent
- Annotations
- @inline()
-
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
final
def
beforeOwnPhase[T](op: ⇒ T): T
- Definition Classes
- SubComponent
- Annotations
- @inline()
-
def
clone(): AnyRef
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
def
enabled: Boolean
Is this component enabled? Default is true.
Is this component enabled? Default is true.
- Definition Classes
- SubComponent
- def ensuring(cond: (TailCalls) ⇒ Boolean, msg: ⇒ Any): TailCalls
- def ensuring(cond: (TailCalls) ⇒ Boolean): TailCalls
- def ensuring(cond: Boolean, msg: ⇒ Any): TailCalls
- def ensuring(cond: Boolean): TailCalls
-
final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
finalize(): Unit
- Attributes
- protected[java.lang]
- Definition Classes
- AnyRef
- Annotations
- @throws( classOf[java.lang.Throwable] )
- def formatted(fmtstr: String): String
-
final
def
getClass(): Class[_]
- Definition Classes
- AnyRef → Any
-
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
-
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
-
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
-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
final
def
ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
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
-
def
newTransformer(unit: Global.CompilationUnit): Global.Transformer
The transformer factory
-
final
def
notify(): Unit
- Definition Classes
- AnyRef
-
final
def
notifyAll(): Unit
- Definition Classes
- AnyRef
-
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
-
val
phaseName: String
- Definition Classes
- TailCalls → SubComponent
-
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
-
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
-
val
requires: List[String]
Names of phases required by this component.
Names of phases required by this component. Default is
Nil.- Definition Classes
- SubComponent
-
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
-
final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
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
-
def
toString(): String
- Definition Classes
- AnyRef → Any
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
- def →[B](y: B): (TailCalls, B)
The Scala compiler and reflection APIs.