org.jikesrvm.compilers.opt.mir2mc

Class MachineCodeOffsets

java.lang.Object

org.jikesrvm.compilers.opt.mir2mc.MachineCodeOffsets

public final class MachineCodeOffsets
extends Object

Saves machine code offsets during the compilation of the method.

Information that is needed at runtime is saved in other classes, e.g. OptMachineCodeMap.

Field Summary

Fields

Modifier and Type	Field and Description
private Map<Instruction,Integer>	mcOffsets

Constructor Summary

Constructors

Constructor and Description
MachineCodeOffsets()

Method Summary

Modifier and Type	Method and Description
void	fabricateMachineCodeOffsetForPrologueInstruction(Instruction instr) Fabricates an offset for prologue instructions in methods that are not interruptible to deal with an oddity.
int	getMachineCodeOffset(Instruction inst) Gets the offset into the machine code array (in bytes) that corresponds to the first byte after this instruction.
boolean	lacksMachineCodeOffset(Instruction inst) Checks whether a machine code offset is missing for the instruction.
void	setMachineCodeOffset(Instruction inst, int mcOffset) This method is only for use by opt assemblers to generate code.

Methods inherited from class java.lang.Object

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

Field Detail

mcOffsets

private final Map<Instruction,Integer> mcOffsets

Constructor Detail

MachineCodeOffsets

MachineCodeOffsets()

Method Detail

setMachineCodeOffset

public void setMachineCodeOffset(Instruction inst,
                                 int mcOffset)

This method is only for use by opt assemblers to generate code. It sets the machine code offset of the instruction as described in getMachineCodeOffset(Instruction).

Parameters:

inst - the instruction whose offset will be set

mcOffset - the offset (in bytes) for the instruction

getMachineCodeOffset

public int getMachineCodeOffset(Instruction inst)

Gets the offset into the machine code array (in bytes) that corresponds to the first byte after this instruction.

This method only returns a valid value after it has been set as a side-effect of a call to generateCode in AssemblerOpt during final assembly.

To get the offset in INSTRUCTIONs you must shift by LG_INSTRUCTION_SIZE.

Parameters:

inst - the instruction whose offset is queried

Returns:

the offset (in bytes) of the machinecode instruction generated for the IR instruction in the final machinecode

Throws:

OptimizingCompilerException - when no machine code offset is present for the instruction

lacksMachineCodeOffset

public boolean lacksMachineCodeOffset(Instruction inst)

Checks whether a machine code offset is missing for the instruction.

Parameters:

inst - the instruction to check

Returns:

true if the instruction never had a machine code offset set

fabricateMachineCodeOffsetForPrologueInstruction

public void fabricateMachineCodeOffsetForPrologueInstruction(Instruction instr)

Fabricates an offset for prologue instructions in methods that are not interruptible to deal with an oddity.

Note: General clients must not call this method.

Parameters:

instr - a prologue instruction in a method that's not interruptible