/*
* $Id$
*
* Copyright (C) 2003-2015 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.vm.x86.compiler.l1a;
import org.jnode.assembler.Label;
import org.jnode.assembler.x86.X86Assembler;
import org.jnode.assembler.x86.X86Register;
import org.jnode.assembler.x86.X86Register.GPR;
import org.jnode.assembler.x86.X86Register.GPR64;
import org.jnode.vm.JvmType;
import org.jnode.vm.classmgr.VmConstString;
import org.jnode.vm.facade.VmUtils;
import org.jnode.vm.x86.compiler.X86CompilerHelper;
/**
* @author Patrik Reali
* @author Ewout Prangsma (epr@users.sourceforge.net)
*/
final class RefItem extends WordItem {
// generate unique labels for writeStatics (should use current label)
private long labelCounter;
private VmConstString value;
/**
* Initialize a blank item
*
* @param factory
*/
RefItem(ItemFactory factory) {
super(factory);
}
final void initialize(EmitterContext ec, byte kind, short offsetToFP, X86Register reg, VmConstString val) {
super.initialize(ec, kind, reg, offsetToFP);
this.value = val;
}
/**
* @see org.jnode.vm.x86.compiler.l1a.WordItem#cloneConstant(EmitterContext)
*/
protected WordItem cloneConstant(EmitterContext ec) {
return factory.createAConst(ec, getValue());
}
/**
* Get the JVM type of this item
*
* @return the JVM type
*/
int getType() {
return JvmType.REFERENCE;
}
/**
* Gets the value of this reference. Item must have a CONSTANT kind.
*
* @return
*/
VmConstString getValue() {
if (VmUtils.verifyAssertions()) VmUtils._assert(getKind() == Kind.CONSTANT, "kind == Kind.CONSTANT");
return value;
}
/**
* Is the value of this item null.
* Item must have a CONSTANT kind.
*
* @return
*/
boolean isNull() {
if (VmUtils.verifyAssertions()) VmUtils._assert(getKind() == Kind.CONSTANT, "kind == Kind.CONSTANT");
return (value == null);
}
/**
* Load my constant to the given os.
*
* @param os
* @param reg
*/
protected void loadToConstant(EmitterContext ec, X86Assembler os,
GPR reg) {
if (value == null) {
os.writeXOR(reg, reg);
} else {
X86CompilerHelper helper = ec.getHelper();
final Label l = new Label(ec.getHelper().getLabelPrefix() + "ref_" + labelCounter++ + "_");
if (os.isCode32()) {
helper.writeGetStaticsEntry(l, reg, value);
} else {
helper.writeGetStaticsEntry64(l, (GPR64) reg, value);
}
}
}
/**
* Pop the top of the FPU stack into the given memory location.
*
* @param os
* @param reg
* @param disp
*/
protected void popFromFPU(X86Assembler os, GPR reg, int disp) {
notImplemented();
}
/**
* Push my constant on the stack using the given os.
*
* @param os
*/
protected void pushConstant(EmitterContext ec, X86Assembler os) {
if (value == null) {
// Push const not supported in 64-bit mode,
// but PUSH imm32 will sign-extend to 64-bit
os.writePUSH(0);
} else {
X86CompilerHelper helper = ec.getHelper();
Label l = new Label(ec.getHelper().getLabelPrefix() + "ref_" + labelCounter+++ "_");
helper.writePushStaticsEntry(l, value);
}
}
/**
* Push the given memory location on the FPU stack.
*
* @param os
* @param reg
* @param disp
*/
protected void pushToFPU(X86Assembler os, GPR reg, int disp) {
notImplemented();
}
}