com.oracle.graal.lir

Class LIRInsertionBuffer

java.lang.Object

com.oracle.graal.lir.LIRInsertionBuffer

public final class LIRInsertionBuffer
extends Object

A buffer to enqueue updates to a list. This avoids frequent re-sizing of the list and copying of list elements when insertions are done at multiple positions of the list. Additionally, it ensures that the list is not modified while it is, e.g., iterated, and instead only modified once after the iteration is done.

The buffer uses internal data structures to store the enqueued updates. To avoid allocations, a buffer can be re-used. Call the methods in the following order: init(java.util.List<com.oracle.graal.lir.LIRInstruction>), append(int, com.oracle.graal.lir.LIRInstruction), append(int, com.oracle.graal.lir.LIRInstruction), ..., finish(), init(java.util.List<com.oracle.graal.lir.LIRInstruction>), ...

Note: This class does not depend on LIRInstruction, so we could make it a generic utility class.

Field Summary

Fields

Modifier and Type	Field and Description
private int[]	indexAndCount List of insertion points.
private int	indexAndCountSize
private List<LIRInstruction>	lir The lir list where ops of this buffer should be inserted later (null when uninitialized).
private List<LIRInstruction>	ops The LIROps to be inserted.

Constructor Summary

Constructors

Constructor and Description
LIRInsertionBuffer()

Method Summary

Modifier and Type	Method and Description
void	append(int index, LIRInstruction op) Enqueue a new instruction that will be appended to the instruction list when finish() is called.
private void	appendNew(int index, int count)
private int	countAt(int i)
void	finish() Append all enqueued instructions to the instruction list.
private int	indexAt(int i)
void	init(List<LIRInstruction> newLir) Initialize this buffer.
boolean	initialized()
List<LIRInstruction>	lirList()
private int	numberOfInsertionPoints()
private void	setCountAt(int i, int value)
private boolean	verify()

Methods inherited from class java.lang.Object

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

Field Detail

lir

private List<LIRInstruction> lir

The lir list where ops of this buffer should be inserted later (null when uninitialized).

indexAndCount

private int[] indexAndCount

List of insertion points. index and count are stored alternately: indexAndCount[i * 2]: the index into lir list where "count" ops should be inserted indexAndCount[i * 2 + 1]: the number of ops to be inserted at index

indexAndCountSize

private int indexAndCountSize

ops

private final List<LIRInstruction> ops

The LIROps to be inserted.

Constructor Detail

LIRInsertionBuffer

public LIRInsertionBuffer()

Method Detail

init

public void init(List<LIRInstruction> newLir)

Initialize this buffer. This method must be called before using append(int, com.oracle.graal.lir.LIRInstruction).

initialized

public boolean initialized()

lirList

public List<LIRInstruction> lirList()

append

public void append(int index,
                   LIRInstruction op)

Enqueue a new instruction that will be appended to the instruction list when finish() is called. The new instruction is added before the existing instruction with the given index. This method can only be called with increasing values of index, e.g., once an instruction was appended with index 4, subsequent instructions can only be appended with index 4 or higher.

finish

public void finish()

Append all enqueued instructions to the instruction list. After that, init(List) can be called again to re-use this buffer.

appendNew

private void appendNew(int index,
                       int count)

setCountAt

private void setCountAt(int i,
                        int value)

numberOfInsertionPoints

private int numberOfInsertionPoints()

indexAt

private int indexAt(int i)

countAt

private int countAt(int i)

verify

private boolean verify()