scala.tools.nsc.backend.opt.Inliners
Inliner
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package Inliners
Classifies a pair (caller, callee) into one of four categories:
Classifies a pair (caller, callee) into one of four categories:
(a) inlining should be performed, classified in turn into:
(a.1) InlineableAtThisCaller: unconditionally at this caller
(a.2) FeasibleInline: it only remains for certain access requirements to be met (see IMethodInfo.accessRequirements())
(b) inlining shouldn't be performed, classified in turn into:
(b.1) DontInlineHere: indicates that this particular occurrence of the callee at the caller shouldn't be inlined.
NeverSafeToInline: the callee can't be inlined anywhere, irrespective of caller.The classification above is computed by isStampedForInlining() based on which analyzeInc() goes on to:
Test two objects for inequality.
Test two objects for inequality.
true if !(this == that), false otherwise.
Equivalent to x.hashCode except for boxed numeric types and null.
Equivalent to x.hashCode except for boxed numeric types and null.
For numerics, it returns a hash value which is consistent
with value equality: if two value type instances compare
as true, then ## will produce the same hash value for each
of them.
For null returns a hashcode where null.hashCode throws a
NullPointerException.
a hash value consistent with ==
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
true if the receiver object is equivalent to the argument; false otherwise.
A transformation local to the body of the IMethod received as argument.
A transformation local to the body of the IMethod received as argument.
An inlining decision consists in replacing a callsite with the body of the callee.
Please notice that, because analyzeMethod() itself may modify a method body,
the particular callee bodies that end up being inlined depend on the particular order in which methods are visited
(no topological sorting over the call-graph is attempted).
Making an inlining decision requires type-flow information for both caller and callee. Regarding the caller, such information is needed only for basic blocks containing inlining candidates (and their transitive predecessors). This observation leads to using a custom type-flow analysis (MTFAGrowable) that can be re-inited, i.e. that reuses lattice elements (type-flow information computed in a previous iteration) as starting point for faster convergence in a new iteration.
The mechanics of inlining are iterative for a given invocation of analyzeMethod(m),
and are affected by inlinings from previous iterations
(ie, "heuristic" rules are based on statistics tracked for that purpose):
(1) before the iterations proper start, so-called preinlining is performed.
Those callsites whose (receiver, concreteMethod) are both known statically
can be analyzed for inlining before computing a type-flow. Details in preInline()
(2) the first iteration computes type-flow information for basic blocks containing inlining candidates
(and their transitive predecessors), so called relevantBBs basic blocks.
The ensuing analysis of each candidate (performed by analyzeInc())
may result in a CFG isomorphic to that of the callee being inserted in place of the callsite
(i.e. a CALL_METHOD instruction is replaced with a single-entry single-exit CFG,
a substitution we call "successful inlining").
(3) following iterations have relevantBBs updated to focus on the inlined basic blocks and their successors only.
Details in MTFAGrowable.reinit()
Cast the receiver object to be of type T0.
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics.
Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at
runtime, while the expression List(1).asInstanceOf[List[String]] will not.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException if the receiver object is not an instance of the erasure of type T0.
Create a copy of the receiver object.
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
a copy of the receiver object.
not specified by SLS as a member of AnyRef
Tests whether the argument (that) is a reference to the receiver object (this).
Tests whether the argument (that) is a reference to the receiver object (this).
The eq method implements an equivalence relation on
non-null instances of AnyRef, and has three additional properties:
x and y of type AnyRef, multiple invocations of
x.eq(y) consistently returns true or consistently returns false.x of type AnyRef, x.eq(null) and null.eq(x) returns false.null.eq(null) returns true. When overriding the equals or hashCode methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they
should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
true if the argument is a reference to the receiver object; false otherwise.
The equality method for reference types.
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as
well as the interaction between finalize and non-local returns
and exceptions, are all platform dependent.
not specified by SLS as a member of AnyRef
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
not specified by SLS as a member of AnyRef
The hashCode method for reference types.
Test whether the dynamic type of the receiver object is T0.
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.isInstanceOf[String] will return false, while the
expression List(1).isInstanceOf[List[String]] will return true.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the specified type.
true if the receiver object is an instance of erasure of type T0; false otherwise.
Equivalent to !(this eq that).
Equivalent to !(this eq that).
true if the argument is not a reference to the receiver object; false otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Should method 'sym' being called in 'receiver' be loaded from disk?
Creates a String representation of this object.
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
a String representation of the object.
Simple inliner.