org.jikesrvm.compilers.opt.ir
Class GCIRMapElement

java.lang.Object
  org.jikesrvm.compilers.opt.ir.GCIRMapElement

public final class GCIRMapElement
extends Object

This class holds each element in the GCIRMap

inst

private final Instruction inst

The instruction, i.e., GC point

regSpillList

private final List<RegSpillListElement> regSpillList

The list of references (either symbolic regs or physical regs & spills)

GCIRMapElement

public GCIRMapElement(Instruction inst,
                      List<RegSpillListElement> regSpillList)

Constructor

Parameters:

inst - the instruction of interest

regSpillList - the list of references either symbolic (before regalloc) or physical/spill location (after regalloc)

createTwin

public GCIRMapElement createTwin(Instruction inst)

Create a twin entry: required when the same MIR GC point is split into two instructions, both of which are PEIs after register allocation/GCIRMap creation.

getInstruction

public Instruction getInstruction()

return the instruction with this entry

Returns:

the instruction with this entry

regSpillList

public List<RegSpillListElement> regSpillList()

returns an enumerator to access the registers/spills for this entry

Returns:

an enumerator to access the registers/spills for this entry

addRegSpillElement

public void addRegSpillElement(RegSpillListElement e)

Add a new spill list element for this map element

deleteRegSpillElement

public void deleteRegSpillElement(RegSpillListElement e)

Delete a spill list element from this map element

countNumElements

public int countNumElements()

Counts and returns the number of references for this map

Returns:

the number of references, either regs or spills for this map

countNumRegElements

public int countNumRegElements()

Counts and returns the number of register elements (not spills) for this entry

Returns:

the number of register elements for this entry

countNumSpillElements

public int countNumSpillElements()

Counts and returns the number of spill for this entry

Returns:

the number of spill for this entry

toString

public String toString()

Return a string version of this object

Overrides:

toString in class Object

Returns:

a string version of this object