spiglet.translate.graph
Class RegisterAlloc<T,R>

java.lang.Object
  spiglet.translate.graph.RegisterAlloc<T,R>

Type Parameters:

T - the type of the variables in an interference graph

R - the type of the registers that variables are allocated to

Direct Known Subclasses:

LinearScanAlloc

public abstract class RegisterAlloc<T,R>
extends java.lang.Object

This abstract class specifies the interface to analyze an interference graph and the metadata of the variables contained therein to allocate those variables to a pool of registers.

Author:

Santoso Wijaya

See Also:

InterferenceGraph

Field Summary

protected java.util.Set<R>

registers An unmodifiable set of general-purpose registers, for lookup reference.

Constructor Summary

RegisterAlloc(java.util.Set<R> pool)
Construct an allocator with a given pool of general purpose registers.

Method Summary

java.util.Map<T,R>	getAllocation(FlowGraph<T> graph) Returns the mapping of all variables to their allocated registers, given a control flow graph from which to infer.
abstract java.util.Map<T,R>	getAllocation(FlowGraph<T> graph, java.util.Map<T,R> preAlloc) Returns the mapping of all variables to their allocated registers, given a control flow graph from which to infer.
java.util.Map<T,R>	getRegAllocation(FlowGraph<T> graph) Returns the mapping of only those variables that are mapped to registers, given a control flow graph from which to infer.
abstract java.util.Map<T,R>	getRegAllocation(FlowGraph<T> graph, java.util.Map<T,R> preAlloc) Returns the mapping of only those variables that are mapped to registers, given a control flow graph from which to infer.
abstract java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

registers

protected java.util.Set<R> registers

An unmodifiable set of general-purpose registers, for lookup reference.

Constructor Detail

RegisterAlloc

public RegisterAlloc(java.util.Set<R> pool)

Construct an allocator with a given pool of general purpose registers.

Parameters:

pool - the set of general registers

Method Detail

getAllocation

public java.util.Map<T,R> getAllocation(FlowGraph<T> graph)

Returns the mapping of all variables to their allocated registers, given a control flow graph from which to infer. If a variable is mapped to null, that means the variable is spilled.

Parameters:

graph - the control flow graph

Returns:

the mapping of variables to their allocated registers (null if spilled)

getAllocation

public abstract java.util.Map<T,R> getAllocation(FlowGraph<T> graph,
                                                 java.util.Map<T,R> preAlloc)

Returns the mapping of all variables to their allocated registers, given a control flow graph from which to infer. If a variable is mapped to null, that means the variable is spilled. A pre-allocation of variables to registers is also given, to indicate to the allocator that such a mapping must remain in the final allocation result. The returned allocation mapping also includes the mapping in preAlloc.

Parameters:

graph - the control flow graph

preAlloc - the pre-allocation mapping

Returns:

the mapping of variables to their allocated registers (null if spilled)

getRegAllocation

public java.util.Map<T,R> getRegAllocation(FlowGraph<T> graph)

Returns the mapping of only those variables that are mapped to registers, given a control flow graph from which to infer. Spilled variables do not appear in the key set of the returned map.

Parameters:

graph - the control flow graph

Returns:

the mapping of variables to their allocated registers; no variable is mapped to null

getRegAllocation

public abstract java.util.Map<T,R> getRegAllocation(FlowGraph<T> graph,
                                                    java.util.Map<T,R> preAlloc)

Returns the mapping of only those variables that are mapped to registers, given a control flow graph from which to infer. Spilled variables do not appear in the key set of the returned map. A pre-allocation of variables to registers is also given, to indicate to the allocator that such a mapping must remain in the final allocation result. The returned allocation mapping also includes the mapping in preAlloc.

Parameters:

graph - the control flow graph

preAlloc - the pre-allocation mapping

Returns:

the mapping of variables to their allocated registers; no variable is mapped to null

toString

public abstract java.lang.String toString()

Overrides:

toString in class java.lang.Object