Cosmos/source/Indy.IL2CPU.IL.X86/Unbox.cs
2008-02-29 18:03:56 +00:00

66 lines
No EOL
2.4 KiB
C#

using System;
using System.IO;
using CPU = Indy.IL2CPU.Assembler;
using CPUx86 = Indy.IL2CPU.Assembler.X86;
using System.Reflection;
using Indy.IL2CPU.Assembler;
namespace Indy.IL2CPU.IL.X86 {
[OpCode(OpCodeEnum.Unbox)]
public class Unbox: Op {
private int mTypeId;
private string mThisLabel;
private string mNextOpLabel;
private Type mType;
private int mTypeSize;
private int mCurrentILOffset;
public Unbox(ILReader aReader, MethodInformation aMethodInfo)
: base(aReader, aMethodInfo) {
mType = aReader.OperandValueType;
if (mType == null) {
throw new Exception("Unable to determine Type!");
}
mTypeSize = Engine.GetFieldStorageSize(mType);
mTypeId = Engine.RegisterType(mType);
mThisLabel = GetInstructionLabel(aReader);
mNextOpLabel = GetInstructionLabel(aReader.NextPosition);
mCurrentILOffset = aReader.Position;
}
public override void DoAssemble() {
string mReturnNullLabel = mThisLabel + "_ReturnNull";
new CPUx86.Move(CPUx86.Registers.EAX, CPUx86.Registers.AtESP);
new CPUx86.Compare(CPUx86.Registers.EAX, "0");
new CPUx86.JumpIfZero(mReturnNullLabel);
new CPUx86.Pushd(CPUx86.Registers.AtEAX);
Assembler.StackContents.Push(new StackContent(4, typeof(uint)));
new CPUx86.Pushd("0" + mTypeId + "h");
Assembler.StackContents.Push(new StackContent(4, typeof(uint)));
MethodBase xMethodIsInstance = Engine.GetMethodBase(Engine.GetType("", "Indy.IL2CPU.VTablesImpl"), "IsInstance", "System.Int32", "System.Int32");
Engine.QueueMethod(xMethodIsInstance);
Op xOp = new Call(xMethodIsInstance, mCurrentILOffset);
xOp.Assembler = Assembler;
xOp.Assemble();
new CPUx86.Pop(CPUx86.Registers.EAX);
Assembler.StackContents.Pop();
new CPUx86.Compare(CPUx86.Registers.EAX, "0");
new CPUx86.JumpIfEquals(mReturnNullLabel);
new CPUx86.Pop(CPUx86.Registers.EAX);
int xSize = mTypeSize;
if (xSize % 4 > 0) {
xSize += 4 - (xSize % 4);
}
int xItems = xSize /4;
for (int i = xItems - 1; i >= 0; i--) {
new CPUx86.Pushd("[eax + " + ((i * 4) + ObjectImpl.FieldDataOffset) + "]");
}
Assembler.StackContents.Push(new StackContent(mTypeSize, mType));
new CPUx86.JumpAlways(mNextOpLabel);
new CPU.Label(mReturnNullLabel);
new CPUx86.Add(CPUx86.Registers.ESP, "4");
new CPUx86.Pushd("0");
Assembler.StackContents.Push(new StackContent(4, typeof(object)));
}
}
}