/*
JPC: An x86 PC Hardware Emulator for a pure Java Virtual Machine
Copyright (C) 2012-2013 Ian Preston
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as published by
the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
Details (including contact information) can be found at:
jpc.sourceforge.net
or the developer website
sourceforge.net/projects/jpc/
End of licence header
*/
package org.jpc.emulator.execution.opcodes.vm;
import org.jpc.emulator.execution.*;
import org.jpc.emulator.execution.decoder.*;
import org.jpc.emulator.processor.*;
import org.jpc.emulator.processor.fpu64.*;
import static org.jpc.emulator.processor.Processor.*;
public class jcxz_Jw extends Executable
{
final int jmp;
final int blockLength;
final int instructionLength;
public jcxz_Jw(int blockStart, int eip, int prefices, PeekableInputStream input)
{
super(blockStart, eip);
jmp = Modrm.Jw(input);
instructionLength = (int)input.getAddress()-eip;
blockLength = eip-blockStart+instructionLength;
}
public Branch execute(Processor cpu)
{
if (cpu.r_cx.get16() == 0)
{
int target = (cpu.eip + jmp + blockLength) & 0xffff;
cpu.cs.checkAddress(target);
cpu.eip = target;
return Branch.T1;
}
else
{
cpu.eip += blockLength;
return Branch.T2;
}
}
public boolean isBranch()
{
return true;
}
public String toString()
{
return this.getClass().getName();
}
}