org.apache.commons.nabla.automatic.instructions
Class NarrowingTransformer

java.lang.Object
  org.apache.commons.nabla.automatic.instructions.NarrowingTransformer

All Implemented Interfaces:

InstructionsTransformer

public class NarrowingTransformer
extends java.lang.Object
implements InstructionsTransformer

Differentiation transformer for narrowing a differential part on the stack to a double.

Some instructions (D2I, D2L, D2F, POP2) may handle differential pair on the stack by simply popping the differential part out before being applied.

Method Summary

static InstructionsTransformer	getInstance() Get the singleton instance.
org.objectweb.asm.tree.InsnList	getReplacement(org.objectweb.asm.tree.AbstractInsnNode insn, MethodDifferentiator methodDifferentiator) Get the replacement instructions.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static InstructionsTransformer getInstance()

Get the singleton instance.

We use here the Initialization on Demand Holder idiom.

Returns:

the singleton instance

getReplacement

public org.objectweb.asm.tree.InsnList getReplacement(org.objectweb.asm.tree.AbstractInsnNode insn,
                                                      MethodDifferentiator methodDifferentiator)
                                               throws DifferentiationException

Get the replacement instructions.

Specified by:

getReplacement in interface InstructionsTransformer

Parameters:

insn - original instruction

methodDifferentiator - method differentiator driving this transformer

Returns:

replacement instructions

Throws:

DifferentiationException - if the method differentiator cannot provide a temporary variable