org.graalvm.compiler.lir

Class LIRInsertionBuffer

java.lang.Object

org.graalvm.compiler.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: LIRInsertionBuffer.init(java.util.List<org.graalvm.compiler.lir.LIRInstruction>), LIRInsertionBuffer.append(int, org.graalvm.compiler.lir.LIRInstruction), LIRInsertionBuffer.append(int, org.graalvm.compiler.lir.LIRInstruction), ..., LIRInsertionBuffer.finish(), LIRInsertionBuffer.init(java.util.List<org.graalvm.compiler.lir.LIRInstruction>), ...

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

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 LIRInsertionBuffer.finish() is called.
void	finish() Append all enqueued instructions to the instruction list.
void	init(List<LIRInstruction> newLir) Initialize this buffer.
boolean	initialized()
List<LIRInstruction>	lirList()

Methods inherited from class java.lang.Object

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

Constructor Detail

LIRInsertionBuffer

public LIRInsertionBuffer()

Method Detail

init

public void init(List<LIRInstruction> newLir)

Initialize this buffer. This method must be called before using LIRInsertionBuffer.append(int, org.graalvm.compiler.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 LIRInsertionBuffer.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, LIRInsertionBuffer.init(List) can be called again to re-use this buffer.