public override void Execute(_MethodInfo aMethod, ILOpCode aOpCode)
{
var xEndLabel = GetLabel(aMethod, aOpCode) + ".End";
// size
XS.Pop(ECX);
// value
XS.Pop(EBX);
// address
XS.Pop(EDI);
XS.Compare(ECX, 0);
XS.Jump(ConditionalTestEnum.Equal, xEndLabel);
XS.Set(EDI, BL, destinationIsIndirect: true);
XS.Compare(ECX, 1);
XS.Jump(ConditionalTestEnum.Equal, xEndLabel);
XS.Set(ESI, EDI);
XS.Increment(EDI);
XS.Decrement(ECX);
new Movs {
Prefixes = InstructionPrefixes.Repeat, Size = 8
};
XS.Label(xEndLabel);
}
public override void Execute(_MethodInfo aMethod, ILOpCode aOpCode)
{
var xStackItem = aOpCode.StackPopTypes[0];
var xStackItemSize = SizeOfType(xStackItem);
var xSize = Math.Max(xStackItemSize, SizeOfType(aOpCode.StackPopTypes[1]));
if (xSize > 4)
{
if (TypeIsFloat(xStackItem))
{
XS.SSE.MoveSS(XMM0, ESP, sourceIsIndirect: true);
XS.Add(XSRegisters.ESP, 8);
XS.SSE.MoveSS(XMM1, ESP, sourceIsIndirect: true);
XS.SSE.XorPS(XMM2, XMM2);
XS.SSE.DivPS(XMM1, XMM0);
XS.SSE.MoveSS(ESP, XMM2, destinationIsIndirect: true);
}
else
{
string BaseLabel = GetLabel(aMethod, aOpCode) + ".";
string LabelShiftRight = BaseLabel + "ShiftRightLoop";
string LabelNoLoop = BaseLabel + "NoLoop";
string LabelEnd = BaseLabel + "End";
// divisor
//low
XS.Set(ESI, ESP, sourceIsIndirect: true);
//high
XS.Set(XSRegisters.EDI, XSRegisters.ESP, sourceDisplacement: 4);
//dividend
// low
XS.Set(XSRegisters.EAX, XSRegisters.ESP, sourceDisplacement: 8);
//high
XS.Set(XSRegisters.EDX, XSRegisters.ESP, sourceDisplacement: 12);
// pop both 8 byte values
XS.Add(XSRegisters.ESP, 16);
// set flags
XS.Or(XSRegisters.EDI, XSRegisters.EDI);
// if high dword of divisor is already zero, we dont need the loop
XS.Jump(CPUx86.ConditionalTestEnum.Zero, LabelNoLoop);
// set ecx to zero for counting the shift operations
XS.Xor(XSRegisters.ECX, XSRegisters.ECX);
XS.Label(LabelShiftRight);
// shift divisor 1 bit right
XS.ShiftRightDouble(ESI, EDI, 1);
XS.ShiftRight(XSRegisters.EDI, 1);
// increment shift counter
XS.Increment(XSRegisters.ECX);
// set flags
XS.Or(XSRegisters.EDI, XSRegisters.EDI);
// loop while high dword of divisor till it is zero
XS.Jump(CPUx86.ConditionalTestEnum.NotZero, LabelShiftRight);
// shift the divident now in one step
// shift divident CL bits right
XS.ShiftRightDouble(EAX, EDX, CL);
XS.ShiftRight(XSRegisters.EDX, CL);
// so we shifted both, so we have near the same relation as original values
// divide this
XS.Divide(XSRegisters.ESI);
// save remainder to stack
XS.Push(0);
XS.Push(XSRegisters.EDX);
//TODO: implement proper derivation correction and overflow detection
XS.Jump(LabelEnd);
XS.Label(LabelNoLoop);
//save high dividend
XS.Set(XSRegisters.ECX, XSRegisters.EAX);
XS.Set(XSRegisters.EAX, XSRegisters.EDX);
// zero EDX, so that high part is zero -> reduce overflow case
XS.Xor(XSRegisters.EDX, XSRegisters.EDX);
// divide high part
XS.Divide(XSRegisters.ESI);
XS.Set(XSRegisters.EAX, XSRegisters.ECX);
// divide low part
XS.Divide(XSRegisters.ESI);
// save remainder result
XS.Push(0);
XS.Push(XSRegisters.EDX);
XS.Label(LabelEnd);
}
}
else
{
if (TypeIsFloat(xStackItem))
{
XS.SSE.MoveSS(XMM0, ESP, sourceIsIndirect: true);
XS.Add(XSRegisters.ESP, 4);
XS.SSE.MoveSS(XMM1, ESP, sourceIsIndirect: true);
XS.Add(XSRegisters.ESP, 4);
XS.SSE.XorPS(XMM2, XMM2);
XS.SSE.DivPS(XMM1, XMM0);
XS.Sub(XSRegisters.ESP, 4);
XS.SSE.MoveSS(ESP, XMM2, destinationIsIndirect: true);
}
else
{
XS.Pop(XSRegisters.ECX);
XS.Pop(XSRegisters.EAX); // gets devised by ecx
XS.Xor(XSRegisters.EDX, XSRegisters.EDX);
XS.Divide(XSRegisters.ECX); // => EAX / ECX
XS.Push(XSRegisters.EDX);
}
}
}
public static void Assemble(Assembler aAssembler, _MethodInfo aMethod, OpMethod xMethod, string currentLabel, Type objectType, MethodBase constructor)
{
// call cctor:
if (aMethod != null)
{
var xCctor = (objectType.GetConstructors(BindingFlags.Static | BindingFlags.NonPublic) ?? Array.Empty <ConstructorInfo>()).SingleOrDefault();
if (xCctor != null)
{
XS.Call(LabelName.Get(xCctor));
EmitExceptionLogic(aAssembler, aMethod, xMethod, true, null, ".AfterCCTorExceptionCheck");
XS.Label(".AfterCCTorExceptionCheck");
}
}
if (objectType.IsValueType)
{
#region Valuetypes
XS.Comment("ValueType");
XS.Comment("Type: " + objectType);
/*
* Current sitation on stack:
* $ESP Arg
* $ESP+.. other items
*
* What should happen:
* + The stack should be increased to allow space to contain:
* + .ctor arguments
* + struct _pointer_ (ref to start of emptied space)
* + empty space for struct
* + arguments should be copied to the new place
* + old place where arguments were should be cleared
* + pointer should be set
* + call .ctor
*/
// Size of return value - we need to make room for this on the stack.
uint xStorageSize = Align(SizeOfType(objectType), 4);
XS.Comment("StorageSize: " + xStorageSize);
if (xStorageSize == 0)
{
throw new Exception("ValueType storage size cannot be 0.");
}
uint xArgSize = 0;
var xParameterList = constructor.GetParameters();
foreach (var xParam in xParameterList)
{
xArgSize = xArgSize + Align(SizeOfType(xParam.ParameterType), 4);
}
XS.Comment("ArgSize: " + xArgSize);
// set source of args copy
XS.Set(ESI, ESP);
// allocate space for struct
XS.Sub(ESP, xStorageSize + 4);
// set destination and count of args copy
XS.Set(EDI, ESP);
XS.Set(ECX, xArgSize / 4);
// move the args to their new location
new CPUx86.Movs {
Size = 32, Prefixes = CPUx86.InstructionPrefixes.Repeat
};
// set struct ptr
XS.Set(EAX, ESP);
XS.Add(EAX, xArgSize + 4);
XS.Set(ESP, EAX, destinationDisplacement: (int)xArgSize);
XS.Push(EAX);
var xOpType = new OpType(xMethod.OpCode, xMethod.Position, xMethod.NextPosition, xMethod.Value.DeclaringType, xMethod.CurrentExceptionRegion);
new Initobj(aAssembler).Execute(aMethod, xOpType);
new Call(aAssembler).Execute(aMethod, xMethod);
// Need to put these *after* the call because the Call pops the args from the stack
// and we have mucked about on the stack, so this makes it right before the next
// op.
#endregion Valuetypes
}
else
{
// If not ValueType, then we need gc
var xParams = constructor.GetParameters();
// array length + 8
bool xHasCalcSize = false;
#region Special string handling
// try calculating size:
if (constructor.DeclaringType == typeof(string))
{
if (xParams.Length == 1 && xParams[0].ParameterType == typeof(char[]))
{
xHasCalcSize = true;
XS.Set(EAX, ESP, sourceDisplacement: 4, sourceIsIndirect: true); // address
XS.Set(EAX, EAX, sourceDisplacement: 8, sourceIsIndirect: true); // element count
XS.Set(EDX, 2); // element size
XS.Multiply(EDX);
XS.Push(EAX);
}
else if (xParams.Length == 3 &&
(xParams[0].ParameterType == typeof(char[]) || xParams[0].ParameterType == typeof(char *)) &&
xParams[1].ParameterType == typeof(int) &&
xParams[2].ParameterType == typeof(int))
{
xHasCalcSize = true;
XS.Set(EAX, ESP, sourceIsIndirect: true);
XS.ShiftLeft(EAX, 1);
XS.Push(EAX);
}
else if (xParams.Length == 2 &&
xParams[0].ParameterType == typeof(char) &&
xParams[1].ParameterType == typeof(int))
{
xHasCalcSize = true;
XS.Set(EAX, ESP, sourceIsIndirect: true);
XS.ShiftLeft(EAX, 1);
XS.Push(EAX);
}
/*
* TODO see if something is needed in stack / register to make them really work
*/
else if (xParams.Length == 3 &&
(xParams[0].ParameterType == typeof(sbyte *) &&
xParams[1].ParameterType == typeof(int) &&
xParams[2].ParameterType == typeof(int)))
{
xHasCalcSize = true;
XS.Push(ESP, isIndirect: true);
}
else if (xParams.Length == 1 && xParams[0].ParameterType == typeof(sbyte *))
{
xHasCalcSize = true;
/* xParams[0] contains a C / ASCII Z string the following ASM is de facto the C strlen() function */
var xSByteCountLabel = currentLabel + ".SByteCount";
XS.Set(EAX, ESP, sourceIsIndirect: true);
XS.Or(ECX, 0xFFFFFFFF);
XS.Label(xSByteCountLabel);
XS.Increment(EAX);
XS.Increment(ECX);
XS.Compare(EAX, 0, destinationIsIndirect: true);
XS.Jump(CPUx86.ConditionalTestEnum.NotEqual, xSByteCountLabel);
XS.Push(ECX);
}
else
{
throw new NotImplementedException("In NewObj, a string ctor implementation is missing!");
}
}
#endregion Special string handling
uint xMemSize = GetStorageSize(objectType);
int xExtraSize = 12; // additional size for set values after alloc
XS.Push((uint)(xMemSize + xExtraSize));
if (xHasCalcSize)
{
XS.Pop(EAX);
XS.Add(ESP, EAX, destinationIsIndirect: true);
}
// todo: probably we want to check for exceptions after calling Alloc
XS.Call(LabelName.Get(GCImplementationRefs.AllocNewObjectRef));
XS.Label(".AfterAlloc");
XS.Push(ESP, isIndirect: true);
XS.Push(ESP, isIndirect: true);
// it's on the stack now 3 times. Once from the Alloc return value, twice from the pushes
// todo: use a cleaner approach here. this class shouldnt assemble the string
string strTypeId = GetTypeIDLabel(constructor.DeclaringType);
XS.Pop(EAX);
XS.Set(EBX, strTypeId, sourceIsIndirect: true);
XS.Set(EAX, EBX, destinationIsIndirect: true);
XS.Set(EAX, (uint)ObjectUtils.InstanceTypeEnum.NormalObject, destinationDisplacement: 4, destinationIsIndirect: true, size: RegisterSize.Int32);
XS.Set(EAX, xMemSize, destinationDisplacement: 8, destinationIsIndirect: true, size: RegisterSize.Int32);
uint xSize = (uint)(from item in xParams
let xQSize = Align(SizeOfType(item.ParameterType), 4)
select(int) xQSize).Take(xParams.Length).Sum();
XS.Push(0);
foreach (var xParam in xParams)
{
uint xParamSize = Align(SizeOfType(xParam.ParameterType), 4);
XS.Comment($"Arg {xParam.Name}: {xParamSize}");
for (int i = 0; i < xParamSize; i += 4)
{
XS.Push(ESP, isIndirect: true, displacement: (int)(xSize + 8));
}
}
XS.Call(LabelName.Get(constructor));
// should the complete error handling happen by ILOp.EmitExceptionLogic?
if (aMethod != null)
{
// todo: only happening for real methods now, not for ctor's ?
XS.Test(ECX, 2);
string xNoErrorLabel = currentLabel + ".NoError" + LabelName.LabelCount.ToString();
XS.Jump(CPUx86.ConditionalTestEnum.Equal, xNoErrorLabel);
PushAlignedParameterSize(constructor);
// an exception occurred, we need to cleanup the stack, and jump to the exit
XS.Add(ESP, 4);
new Comment(aAssembler, "[ Newobj.Execute cleanup end ]");
Jump_Exception(aMethod);
XS.Label(xNoErrorLabel);
}
XS.Pop(EAX);
PushAlignedParameterSize(constructor);
XS.Push(EAX);
XS.Push(0);
}
}
public override void AssembleNew(Assembler aAssembler, object aMethodInfo)
{
var xAssembler = aAssembler;
var xMethodInfo = (_MethodInfo)aMethodInfo;
var xMethodBaseAsInfo = xMethodInfo.MethodBase as global::System.Reflection.MethodInfo;
if (xMethodBaseAsInfo.ReturnType != typeof(void))
{
throw new Exception("Events with return type not yet supported!");
}
/*
* EAX contains the GetInvocationList() array at the index at which it was last used
* EDX contains the index at which the EAX is
* EBX contains the number of items in the array
* ECX contains the argument size
*/
XS.ClearInterruptFlag();
XS.Comment("Get Invoke list count");
var xGetInvocationListMethod = typeof(MulticastDelegate).GetMethod("GetInvocationList");
Ldarg.DoExecute(aAssembler, xMethodInfo, 0);
XS.Call(LabelName.Get(xGetInvocationListMethod));
XS.Add(XSRegisters.ESP, 4);
XS.Pop(XSRegisters.EAX);
XS.Add(XSRegisters.EAX, 8);
XS.Set(XSRegisters.EBX, XSRegisters.EAX, sourceIsIndirect: true);
XS.Comment("Get invoke method");
XS.Add(XSRegisters.EAX, 8);
XS.Set(XSRegisters.EDI, XSRegisters.EAX, sourceIsIndirect: true, sourceDisplacement: 4);
XS.Comment("Get ArgSize");
int xArgSizeOffset = Ldfld.GetFieldOffset(typeof(global::System.Delegate), "$$ArgSize$$");
Ldarg.DoExecute(aAssembler, xMethodInfo, 0);
XS.Add(XSRegisters.ESP, 4);
XS.Pop(XSRegisters.ECX);
XS.Add(XSRegisters.ECX, (uint)xArgSizeOffset);
XS.Set(XSRegisters.ECX, XSRegisters.ECX, sourceIsIndirect: true);
XS.Comment("Set current invoke list index");
XS.Set(XSRegisters.EDX, 0);
XS.Label(".BEGIN_OF_LOOP");
{
XS.Compare(XSRegisters.EDX, XSRegisters.EBX);
XS.Jump(x86.ConditionalTestEnum.GreaterThanOrEqualTo, ".END_OF_INVOKE");
XS.PushAllRegisters();
XS.Comment("Check if delegate has $this");
XS.Set(XSRegisters.EDI, XSRegisters.EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0));
XS.Add(XSRegisters.EDI, 4);
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "System.Object System.Delegate._target"));
XS.Compare(XSRegisters.EDI, 0);
XS.Jump(x86.ConditionalTestEnum.Zero, ".NO_THIS");
XS.Label(".HAS_THIS");
XS.Push(XSRegisters.EDI);
XS.Push(0);
XS.Label(".NO_THIS");
XS.Set(XSRegisters.EDI, XSRegisters.EAX, sourceIsIndirect: true, sourceDisplacement: 4);
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "System.IntPtr System.Delegate._methodPtr"));
XS.Comment("Check if delegate has args");
XS.Compare(XSRegisters.ECX, 0);
XS.Jump(x86.ConditionalTestEnum.Zero, ".NO_ARGS");
XS.Label(".HAS_ARGS");
XS.Sub(XSRegisters.ESP, XSRegisters.ECX);
XS.Push(XSRegisters.EDI);
XS.Set(XSRegisters.EDI, XSRegisters.ESP);
XS.Add(XSRegisters.EDI, 4);
XS.Set(XSRegisters.ESI, XSRegisters.EBP);
XS.Add(XSRegisters.ESI, 8);
new x86.Movs {
Size = 8, Prefixes = x86.InstructionPrefixes.Repeat
};
XS.Pop(XSRegisters.EDI);
XS.Label(".NO_ARGS");
XS.Call(XSRegisters.EDI);
XS.PopAllRegisters();
XS.Increment(XSRegisters.EDX);
XS.Jump(".BEGIN_OF_LOOP");
}
XS.Label(".END_OF_INVOKE");
XS.Set(XSRegisters.EDX, XSRegisters.EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0));
XS.Set(XSRegisters.EDX, XSRegisters.EDX, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "$$ReturnsValue$$"));
XS.Compare(XSRegisters.EDX, 0);
XS.Jump(x86.ConditionalTestEnum.Equal, ".NO_RETURN");
XS.Label(".HAS_RETURN");
XS.Exchange(XSRegisters.EBP, XSRegisters.EDX, destinationDisplacement: 8);
XS.Exchange(XSRegisters.EBP, XSRegisters.EDX, destinationDisplacement: 4);
XS.Exchange(XSRegisters.EBP, XSRegisters.EDX, destinationIsIndirect: true);
XS.Push(XSRegisters.EDX);
XS.Set(XSRegisters.ESP, XSRegisters.EDI, destinationDisplacement: 12);
XS.Label(".NO_RETURN");
XS.EnableInterrupts();
}
public override void Execute(MethodInfo aMethod, ILOpCode aOpCode)
{
var xStackItem = aOpCode.StackPopTypes[0];
var xStackItemSize = SizeOfType(xStackItem);
var xStackItem2 = aOpCode.StackPopTypes[1];
var xStackItem2Size = SizeOfType(xStackItem2);
if (xStackItemSize == 8)
{
// there seem to be an error in MS documentation, there is pushed an int32, but IL shows else
if (xStackItem2Size != 8)
{
throw new Exception("Cosmos.IL2CPU.x86->IL->Div.cs->Error: Expected a size of 8 for Div!");
}
if (TypeIsFloat(xStackItem))
{
// TODO add 0/0 infinity/infinity X/infinity
// value 1
new CPUx86.x87.FloatLoad {
DestinationReg = CPUx86.RegistersEnum.ESP, Size = 64, DestinationIsIndirect = true, DestinationDisplacement = 8
};
// value 2
new CPUx86.x87.FloatDivide {
DestinationReg = CPUx86.RegistersEnum.ESP, DestinationIsIndirect = true, Size = 64
};
// override value 1
new CPUx86.x87.FloatStoreAndPop {
DestinationReg = CPUx86.RegistersEnum.ESP, Size = 64, DestinationIsIndirect = true, DestinationDisplacement = 8
};
// pop value 2
XS.Add(XSRegisters.ESP, 8);
}
else
{
string BaseLabel = GetLabel(aMethod, aOpCode) + ".";
string LabelShiftRight = BaseLabel + "ShiftRightLoop";
string LabelNoLoop = BaseLabel + "NoLoop";
string LabelEnd = BaseLabel + "End";
// divisor
//low
XS.Set(ESI, ESP, sourceIsIndirect: true);
//high
XS.Set(XSRegisters.EDI, XSRegisters.ESP, sourceDisplacement: 4);
//dividend
// low
XS.Set(XSRegisters.EAX, XSRegisters.ESP, sourceDisplacement: 8);
//high
XS.Set(XSRegisters.EDX, XSRegisters.ESP, sourceDisplacement: 12);
// pop both 8 byte values
XS.Add(XSRegisters.ESP, 16);
// set flags
XS.Or(XSRegisters.EDI, XSRegisters.EDI);
// if high dword of divisor is already zero, we dont need the loop
XS.Jump(CPUx86.ConditionalTestEnum.Zero, LabelNoLoop);
// set ecx to zero for counting the shift operations
XS.Xor(XSRegisters.ECX, XSRegisters.ECX);
XS.Label(LabelShiftRight);
// shift divisor 1 bit right
XS.ShiftRightDouble(ESI, EDI, 1);
XS.ShiftRight(XSRegisters.EDI, 1);
// increment shift counter
XS.Increment(XSRegisters.ECX);
// set flags
XS.Or(XSRegisters.EDI, XSRegisters.EDI);
// loop while high dword of divisor till it is zero
XS.Jump(CPUx86.ConditionalTestEnum.NotZero, LabelShiftRight);
// shift the divident now in one step
// shift divident CL bits right
XS.ShiftRightDouble(EAX, EDX, CL);
XS.ShiftRight(XSRegisters.EDX, CL);
// so we shifted both, so we have near the same relation as original values
// divide this
XS.Divide(XSRegisters.ESI);
// save result to stack
XS.Push(0);
XS.Push(XSRegisters.EAX);
//TODO: implement proper derivation correction and overflow detection
XS.Jump(LabelEnd);
XS.Label(LabelNoLoop);
//save high dividend
XS.Set(XSRegisters.ECX, XSRegisters.EAX);
XS.Set(XSRegisters.EAX, XSRegisters.EDX);
// zero EDX, so that high part is zero -> reduce overflow case
XS.Xor(XSRegisters.EDX, XSRegisters.EDX);
// divide high part
XS.Divide(XSRegisters.ESI);
// save high result
XS.Push(XSRegisters.EAX);
XS.Set(XSRegisters.EAX, XSRegisters.ECX);
// divide low part
XS.Divide(XSRegisters.ESI);
// save low result
XS.Push(XSRegisters.EAX);
XS.Label(LabelEnd);
}
}
else
{
if (TypeIsFloat(xStackItem))
{
XS.SSE.MoveSS(XMM0, ESP, sourceIsIndirect: true);
XS.Add(XSRegisters.ESP, 4);
XS.SSE.MoveSS(XMM1, ESP, sourceIsIndirect: true);
XS.SSE.MulSS(XMM0, XMM1);
XS.SSE.MoveSS(XMM1, ESP, sourceIsIndirect: true);
}
else
{
XS.Xor(XSRegisters.EDX, XSRegisters.EDX);
XS.Pop(XSRegisters.ECX);
XS.Pop(XSRegisters.EAX);
XS.Divide(XSRegisters.ECX);
XS.Push(XSRegisters.EAX);
}
}
}
public override void Execute(_MethodInfo aMethod, ILOpCode aOpCode)
{
var xStackItem = aOpCode.StackPopTypes[0];
var xStackItemSize = SizeOfType(xStackItem);
var xStackItem2 = aOpCode.StackPopTypes[0];
var xStackItem2Size = SizeOfType(xStackItem2);
if (xStackItemSize == 8)
{
// there seem to be an error in MS documentation, there is pushed an int32, but IL shows else
if (xStackItem2Size != 8)
{
throw new Exception("Cosmos.IL2CPU.x86->IL->Div.cs->Error: Expected a size of 8 for Div!");
}
if (TypeIsFloat(xStackItem))
{
XS.SSE2.MoveSD(XMM0, ESP, sourceIsIndirect: true);
XS.Add(ESP, 8);
XS.SSE2.MoveSD(XMM1, ESP, sourceIsIndirect: true);
XS.SSE2.DivSD(XMM1, XMM0);
XS.SSE2.MoveSD(ESP, XMM1, destinationIsIndirect: true);
}
else
{
string BaseLabel = GetLabel(aMethod, aOpCode) + ".";
string LabelShiftRight = BaseLabel + "ShiftRightLoop";
string LabelNoLoop = BaseLabel + "NoLoop";
string LabelEnd = BaseLabel + "End";
// divisor
//low
XS.Set(ESI, ESP, sourceIsIndirect: true);
//high
XS.Set(EDI, ESP, sourceDisplacement: 4);
// pop both 8 byte values
XS.Add(ESP, 8);
//dividend
// low
XS.Set(EAX, ESP, sourceIsIndirect: true);
//high
XS.Set(EDX, ESP, sourceDisplacement: 4);
XS.Add(ESP, 8);
// set flags
XS.Or(EDI, EDI);
// if high dword of divisor is already zero, we dont need the loop
XS.Jump(CPUx86.ConditionalTestEnum.Zero, LabelNoLoop);
// set ecx to zero for counting the shift operations
XS.Xor(ECX, ECX);
XS.Label(LabelShiftRight);
// shift divisor 1 bit right
XS.ShiftRightDouble(ESI, EDI, 1);
XS.ShiftRight(EDI, 1);
// increment shift counter
XS.Increment(ECX);
// set flags
XS.Or(EDI, EDI);
// loop while high dword of divisor till it is zero
XS.Jump(CPUx86.ConditionalTestEnum.NotZero, LabelShiftRight);
// shift the divident now in one step
// shift divident CL bits right
XS.ShiftRightDouble(EAX, EDX, CL);
XS.ShiftRight(EDX, CL);
// so we shifted both, so we have near the same relation as original values
// divide this
XS.IntegerDivide(ESI);
// sign extend
XS.SignExtendAX(RegisterSize.Int32);
// save result to stack
XS.Push(EDX);
XS.Push(EAX);
//TODO: implement proper derivation correction and overflow detection
XS.Jump(LabelEnd);
XS.Label(LabelNoLoop);
//save high dividend
XS.Set(ECX, EAX);
XS.Set(EAX, EDX);
// extend that sign is in edx
XS.SignExtendAX(RegisterSize.Int32);
// divide high part
XS.IntegerDivide(ESI);
// save high result
XS.Push(EAX);
XS.Set(EAX, ECX);
// divide low part
XS.Divide(ESI);
// save low result
XS.Push(EAX);
XS.Label(LabelEnd);
}
}
else
{
if (TypeIsFloat(xStackItem))
{
XS.SSE.MoveSS(XMM0, ESP, sourceIsIndirect: true);
XS.Add(XSRegisters.ESP, 4);
XS.SSE.MoveSS(XMM1, ESP, sourceIsIndirect: true);
XS.SSE.DivSS(XMM1, XMM0);
XS.SSE.MoveSS(ESP, XMM1, destinationIsIndirect: true);
}
else
{
XS.Pop(XSRegisters.ECX);
XS.Pop(XSRegisters.EAX);
XS.SignExtendAX(RegisterSize.Int32);
XS.IntegerDivide(XSRegisters.ECX);
XS.Push(XSRegisters.EAX);
}
}
}
public override void Execute(_MethodInfo aMethod, ILOpCode aOpCode)
{
var xStackItem = aOpCode.StackPopTypes[0];
var xSize = Math.Max(SizeOfType(xStackItem), SizeOfType(aOpCode.StackPopTypes[1]));
var xIsFloat = TypeIsFloat(xStackItem);
var xBaseLabel = GetLabel(aMethod, aOpCode);
var xNoDivideByZeroExceptionLabel = xBaseLabel + "_NoDivideByZeroException";
if (xSize > 8)
{
throw new NotImplementedException("Cosmos.IL2CPU.x86->IL->Div.cs->Error: StackSize > 8 not supported");
}
else if (xSize > 4)
{
if (xIsFloat)
{
XS.SSE2.MoveSD(XMM0, ESP, sourceIsIndirect: true);
XS.Add(ESP, 8);
XS.SSE2.MoveSD(XMM1, ESP, sourceIsIndirect: true);
XS.SSE2.DivSD(XMM1, XMM0);
XS.SSE2.MoveSD(ESP, XMM1, destinationIsIndirect: true);
}
else
{
string BaseLabel = GetLabel(aMethod, aOpCode) + ".";
string LabelShiftRight = BaseLabel + "ShiftRightLoop";
string LabelNoLoop = BaseLabel + "NoLoop";
string LabelEnd = BaseLabel + "End";
// divisor
// low
XS.Pop(ESI);
// high
XS.Pop(EDI);
XS.Xor(EAX, EAX);
XS.Or(EAX, ESI);
XS.Or(EAX, EDI);
XS.Jump(ConditionalTestEnum.NotZero, xNoDivideByZeroExceptionLabel);
XS.Call(GetLabel(ExceptionHelperRefs.ThrowDivideByZeroExceptionRef));
XS.Label(xNoDivideByZeroExceptionLabel);
// dividend
// low
XS.Pop(EAX);
// high
XS.Pop(EDX);
// set flags
XS.Or(EDI, EDI);
// if high dword of divisor is already zero, we dont need the loop
XS.Jump(ConditionalTestEnum.Zero, LabelNoLoop);
// set ecx to zero for counting the shift operations
XS.Xor(ECX, ECX);
// push most significant bit of result
XS.Set(EBX, EDI);
XS.Xor(EBX, EDX);
XS.Push(EBX);
XS.Compare(EDI, 0x80000000);
XS.Jump(ConditionalTestEnum.Below, BaseLabel + "divisor_no_neg");
XS.Negate(ESI);
XS.AddWithCarry(EDI, 0);
XS.Negate(EDI);
XS.Label(BaseLabel + "divisor_no_neg");
XS.Compare(EDX, 0x80000000);
XS.Jump(ConditionalTestEnum.Below, BaseLabel + "dividend_no_neg");
XS.Negate(EAX);
XS.AddWithCarry(EDX, 0);
XS.Negate(EDX);
XS.Label(BaseLabel + "dividend_no_neg");
XS.Label(LabelShiftRight);
// shift divisor 1 bit right
XS.ShiftRightDouble(ESI, EDI, 1);
XS.ShiftRight(EDI, 1);
// increment shift counter
XS.Increment(ECX);
// set flags
//XS.Or(EDI, EDI);
XS.Set(EBX, ESI);
XS.And(EBX, 0x80000000);
XS.Or(EBX, EDI);
// loop while high dword of divisor is not zero or most significant bit of low dword of divisor is set
XS.Jump(ConditionalTestEnum.NotZero, LabelShiftRight);
// shift the dividend now in one step
XS.ShiftRightDouble(EAX, EDX, CL);
// shift dividend CL bits right
XS.ShiftRight(EDX, CL);
// so we shifted both, so we have near the same relation as original values
// divide this
XS.IntegerDivide(ESI);
// pop most significant bit of result
XS.Pop(EBX);
XS.Compare(EBX, 0x80000000);
XS.Jump(ConditionalTestEnum.Below, BaseLabel + "_result_no_neg");
XS.Negate(EAX);
XS.Label(BaseLabel + "_result_no_neg");
// sign extend
XS.SignExtendAX(RegisterSize.Int32);
// save result to stack
XS.Push(EDX);
XS.Push(EAX);
//TODO: implement proper derivation correction and overflow detection
XS.Jump(LabelEnd);
XS.Label(LabelNoLoop);
// save high dividend
XS.Set(ECX, EAX);
XS.Set(EAX, EDX);
// extend that sign is in edx
XS.SignExtendAX(RegisterSize.Int32);
// divide high part
XS.IntegerDivide(ESI);
// save high result
XS.Push(EAX);
XS.Set(EAX, ECX);
// divide low part
XS.Divide(ESI);
// save low result
XS.Push(EAX);
XS.Label(LabelEnd);
}
}
else
{
if (xIsFloat)
{
XS.SSE.MoveSS(XMM0, ESP, sourceIsIndirect: true);
XS.Add(ESP, 4);
XS.SSE.MoveSS(XMM1, ESP, sourceIsIndirect: true);
XS.SSE.DivSS(XMM1, XMM0);
XS.SSE.MoveSS(ESP, XMM1, destinationIsIndirect: true);
}
else
{
XS.Pop(ECX);
XS.Test(ECX, ECX);
XS.Jump(ConditionalTestEnum.NotZero, xNoDivideByZeroExceptionLabel);
XS.Call(GetLabel(ExceptionHelperRefs.ThrowDivideByZeroExceptionRef));
XS.Label(xNoDivideByZeroExceptionLabel);
XS.Pop(EAX);
XS.SignExtendAX(RegisterSize.Int32);
XS.IntegerDivide(ECX);
XS.Push(EAX);
}
}
}
public override void AssembleNew(Assembler aAssembler, object aMethodInfo)
{
var xMethodInfo = (Il2cpuMethodInfo)aMethodInfo;
/*
* EAX contains the GetInvocationList() array at the index at which it was last used
* EBX contains the number of items in the array
* ECX contains the argument size
* EDX contains the current index in the array
* ESI contains the size of the return value
* EDI contains the function pointer
*/
XS.ClearInterruptFlag();
XS.Comment("Get Invoke list count");
var xGetInvocationListMethod = typeof(MulticastDelegate).GetMethod("GetInvocationList");
Ldarg.DoExecute(aAssembler, xMethodInfo, 0);
XS.Call(LabelName.Get(xGetInvocationListMethod));
XS.Add(ESP, 4);
XS.Pop(EAX);
XS.Add(EAX, 8);
XS.Set(EBX, EAX, sourceIsIndirect: true);
XS.Comment("Get invoke method");
XS.Add(EAX, 8);
XS.Set(EDI, EAX, sourceIsIndirect: true, sourceDisplacement: 4); // this line can propably can be removed
XS.Comment("Get ArgSize");
int xArgSizeOffset = Ldfld.GetFieldOffset(typeof(Delegate), "$$ArgSize$$");
Ldarg.DoExecute(aAssembler, xMethodInfo, 0);
XS.Add(ESP, 4);
XS.Pop(ECX);
XS.Add(ECX, (uint)xArgSizeOffset);
XS.Set(ECX, ECX, sourceIsIndirect: true);
XS.Comment("Set current invoke list index");
XS.Set(EDX, 0);
XS.Comment("Make space for return value");
int returnSizeOffset = Ldfld.GetFieldOffset(typeof(Delegate), "$$ReturnSize$$");
Ldarg.DoExecute(aAssembler, xMethodInfo, 0);
XS.Add(ESP, 4);
XS.Pop(ESI);
XS.Add(ESI, (uint)returnSizeOffset);
XS.Set(ESI, ESI, sourceIsIndirect: true);
XS.Sub(ESP, ESI);
XS.Label(".BEGIN_OF_LOOP");
{
XS.Compare(EDX, EBX);
XS.Jump(x86.ConditionalTestEnum.GreaterThanOrEqualTo, ".END_OF_INVOKE");
XS.PushAllRegisters();
XS.Comment("Check if delegate has $this");
XS.Set(EDI, EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0));
XS.Add(EDI, 4);
XS.Set(EDI, EDI, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "System.Object System.Delegate._target"));
XS.Set(EDX, ECX); // edx contains the size of the arguments including $this
XS.Compare(EDI, 0);
XS.Jump(x86.ConditionalTestEnum.Zero, ".NO_THIS");
XS.Label(".HAS_THIS");
XS.Push(EDI);
XS.Set(EDI, EDI, sourceIsIndirect: true); // get type of target object
XS.Add(EDX, 4); // we have at least one int of $this
//TODO: In future we might be able to replace the following call with a check
//if the object is boxed and in that case assume its a struct
// safe info from registers which get trashed
XS.Push(EAX);
XS.Push(EBX);
XS.Push(ECX);
XS.Push(EDX);
XS.Push(EDI);
XS.Call(LabelName.Get(VTablesImplRefs.IsStructRef));
XS.Pop(EDI);
// restore values
XS.Pop(EDX);
XS.Pop(ECX);
XS.Pop(EBX);
XS.Pop(EAX);
// now check if target turned out to be struct
XS.Compare(EDI, 1);
XS.Jump(x86.ConditionalTestEnum.Equal, ".Struct"); //structs are just the pointer so we are already done
XS.Push(0);
XS.Add(EDX, 4);
XS.Jump(".NO_THIS");
XS.Label(".Struct");
XS.Add(ESP, ObjectUtils.FieldDataOffset, destinationIsIndirect: true);
XS.Label(".NO_THIS");
XS.Set(EDI, EAX, sourceIsIndirect: true, sourceDisplacement: 4);
XS.Set(EDI, EDI, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "System.IntPtr System.Delegate._methodPtr"));
XS.Set(EBX, 0); // initialise required extra space to 0
XS.Compare(ESI, EDX);
XS.Jump(x86.ConditionalTestEnum.LessThanOrEqualTo, ".NO_RETURN_VALUE_SPACE");
XS.Set(EBX, ESI);
XS.Sub(EBX, ECX);
XS.Label(".NO_RETURN_VALUE_SPACE");
XS.Comment("Check if delegate has args");
XS.Compare(ECX, 0);
XS.Jump(x86.ConditionalTestEnum.Zero, ".NO_ARGS");
XS.Label(".HAS_ARGS");
XS.Sub(ESP, ECX);
XS.Push(EDI);
XS.Set(EDI, ESP);
XS.Add(EDI, 4);
XS.Set(ESI, EBP);
XS.Compare(EBX, 0);
XS.Jump(x86.ConditionalTestEnum.Equal, ".NO_RETURN_EXTRA");
XS.Add(ESI, EBX); // to skip the extra space reserved for the return value
XS.Jump(".AFTER_ADJUST_ESI");
XS.Label(".NO_RETURN_EXTRA");
XS.Add(ESI, 8);
XS.Label(".AFTER_ADJUST_ESI");
new x86.Movs {
Size = 8, Prefixes = x86.InstructionPrefixes.Repeat
};
XS.Pop(EDI);
XS.Label(".NO_ARGS");
XS.Sub(ESP, EBX); // make extra space for the return value
XS.Call(EDI);
XS.Comment("If there is a return value copy it to holding place now");
Ldarg.DoExecute(aAssembler, xMethodInfo, 0);
XS.Add(ESP, 4);
XS.Pop(EAX);
XS.Add(EAX, (uint)returnSizeOffset);
XS.Set(EAX, EAX, sourceIsIndirect: true); // got size of return value
XS.Set(EDI, EBP);
XS.Sub(EDI, EAX);
XS.Label(".RETURN_VALUE_LOOP_START");
XS.Compare(EAX, 0);
XS.Jump(x86.ConditionalTestEnum.LessThanOrEqualTo, ".RETURN_VALUE_LOOP_END");
XS.Pop(EBX);
XS.Set(EDI, EBX, destinationIsIndirect: true);
XS.Add(EDI, 4);
XS.Sub(EAX, 4);
XS.Jump(".RETURN_VALUE_LOOP_START");
XS.Label(".RETURN_VALUE_LOOP_END");
XS.PopAllRegisters();
XS.Increment(EDX);
XS.Jump(".BEGIN_OF_LOOP");
}
XS.Label(".END_OF_INVOKE");
XS.EnableInterrupts();
}
public override void AssembleNew(Cosmos.Assembler.Assembler aAssembler, object aMethodInfo)
{
var xAssembler = (Cosmos.Assembler.Assembler)aAssembler;
var xMethodInfo = (Cosmos.IL2CPU.MethodInfo)aMethodInfo;
var xMethodBaseAsInfo = xMethodInfo.MethodBase as global::System.Reflection.MethodInfo;
if (xMethodBaseAsInfo.ReturnType != typeof(void))
{
throw new Exception("Events with return type not yet supported!");
}
XS.Comment("XXXXXXX");
XS.Exchange(XSRegisters.BX, XSRegisters.BX);
/*
* EAX contains the GetInvocationList() array at the index at which it was last used
* EDX contains the index at which the EAX is
* EBX contains the number of items in the array
* ECX contains the argument size
*/
XS.ClearInterruptFlag();
XS.Label(".DEBUG");
//XS.Label("____DEBUG_FOR_MULTICAST___");
XS.Comment("move address of delegate to eax");
XS.Set(XSRegisters.EAX, XSRegisters.EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0));
var xGetInvocationListMethod = typeof(MulticastDelegate).GetMethod("GetInvocationList");
XS.Comment("push address of delgate to stack");
XS.Push(XSRegisters.EAX);//addrof this
XS.Call(LabelName.Get(xGetInvocationListMethod));
XS.Comment("get address from return value -> eax");
XS.Pop(XSRegisters.EAX);
;//list
XS.Comment("eax+=8 is where the offset where an array's count is");
XS.Set(XSRegisters.EAX, XSRegisters.EAX, sourceIsIndirect: true);
XS.Add(XSRegisters.EAX, 8); //addrof list.Length
XS.Comment("store count in ebx");
XS.Set(XSRegisters.EBX, XSRegisters.EAX, sourceIsIndirect: true); //list.count
XS.Comment("eax+=8 is where the offset where an array's items start");
XS.Add(XSRegisters.EAX, 8); // Put pointer at the first item in the list.
XS.Set(XSRegisters.EDI, 0);
XS.Comment("ecx = ptr to delegate object");
XS.Set(XSRegisters.ECX, XSRegisters.EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0));//addrof the delegate
XS.Comment("ecx points to the size of the delegated methods arguments");
XS.Set(XSRegisters.ECX, XSRegisters.ECX, sourceIsIndirect: true);
XS.Set(XSRegisters.ECX, XSRegisters.ECX, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "$$ArgSize$$")); //the size of the arguments to the method? + 12??? -- 12 is the size of the current call stack.. i think
XS.Xor(XSRegisters.EDX, XSRegisters.EDX);
; //make sure edx is 0
XS.Label(".BEGIN_OF_LOOP");
{
XS.Compare(XSRegisters.EDX, XSRegisters.EBX); //are we at the end of this list
XS.Jump(CPUx86.ConditionalTestEnum.GreaterThanOrEqualTo, ".END_OF_INVOKE_"); //then we better stop
XS.PushAllRegisters();
XS.Comment("esi points to where we will copy the methods argumetns from");
XS.Set(XSRegisters.ESI, XSRegisters.ESP);
XS.Comment("edi = ptr to delegate object");
XS.Set(XSRegisters.EDI, XSRegisters.EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0));
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceIsIndirect: true); // dereference handle
XS.Comment("edi = ptr to delegate object should be a pointer to the delgates context ie (this) for the methods ");
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "System.Object System.Delegate._target"));
XS.Compare(XSRegisters.EDI, 0);
XS.Jump(CPUx86.ConditionalTestEnum.Zero, ".NO_THIS");
XS.Push(XSRegisters.EDI);
XS.Label(".NO_THIS");
XS.Comment("make space for us to copy the arguments too");
XS.Sub(XSRegisters.ESP, XSRegisters.ECX);
XS.Comment("move the current delegate to edi");
XS.Set(XSRegisters.EDI, XSRegisters.EAX, sourceIsIndirect: true);
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceIsIndirect: true); // dereference
XS.Comment("move the methodptr from that delegate to edi ");
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "System.IntPtr System.Delegate._methodPtr")); //
XS.Comment("save methodptr on the stack");
XS.Push(XSRegisters.EDI);
XS.Comment("move location to copy args to");
XS.Set(XSRegisters.EDI, XSRegisters.ESP);
XS.Add(XSRegisters.EDI, 4);
//new CPU.Comment("get above the saved methodptr");
//XS.Sub(XSRegisters.ESP, 4);
//we allocated the argsize on the stack once, and it we need to get above the original args
XS.Comment("we allocated argsize on the stack once");
XS.Comment("add 32 for the Pushad + 16 for the current stack + 4 for the return value");
//uint xToAdd = 32; // skip pushad data
//xToAdd += 4; // method pointer
XS.Set(XSRegisters.ESI, XSRegisters.EBP);
XS.Add(XSRegisters.ESI, 8); // ebp+8 is first argument
new CPUx86.Movs {
Size = 8, Prefixes = CPUx86.InstructionPrefixes.Repeat
};
XS.Pop(XSRegisters.EDI);
XS.Label(".BeforeCall");
XS.Call(XSRegisters.EDI);
XS.Comment("store return -- return stored into edi after popad");
XS.Comment("edi = ptr to delegate object");
XS.Set(XSRegisters.EDI, XSRegisters.EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0));
XS.Comment("edi = ptr to delegate object should be a pointer to the delgates context ie (this) for the methods ");
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceIsIndirect: true); // dereference handle
XS.Set(XSRegisters.EDI, XSRegisters.EDI, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "System.Object System.Delegate._target")); //i really dont get the +12, MtW: that's for the object header
XS.Label(".noTHIStoPop");
XS.PopAllRegisters();
XS.Increment(XSRegisters.EDX);
XS.Add(XSRegisters.EAX, 4);
XS.Jump(".BEGIN_OF_LOOP");
}
XS.Label(".END_OF_INVOKE_");
XS.Comment("get the return value");
XS.Set(XSRegisters.EDX, XSRegisters.EBP, sourceDisplacement: Ldarg.GetArgumentDisplacement(xMethodInfo, 0)); //addrof the delegate
XS.Set(XSRegisters.EDX, XSRegisters.EDX, sourceIsIndirect: true); // dereference handle
XS.Set(XSRegisters.EDX, XSRegisters.EDX, sourceDisplacement: Ldfld.GetFieldOffset(xMethodInfo.MethodBase.DeclaringType, "$$ReturnsValue$$"));
XS.Compare(XSRegisters.EDX, 0);
XS.Jump(CPUx86.ConditionalTestEnum.Equal, ".noReturn");
//may have to expand the return... idk
XS.Exchange(XSRegisters.EBP, XSRegisters.EDX, destinationDisplacement: 8);
XS.Exchange(XSRegisters.EBP, XSRegisters.EDX, destinationDisplacement: 4);
XS.Exchange(XSRegisters.EBP, XSRegisters.EDX, destinationIsIndirect: true);
XS.Push(XSRegisters.EDX);//ebp
XS.Set(XSRegisters.ESP, XSRegisters.EDI, destinationDisplacement: 12);
XS.Label(".noReturn");
XS.EnableInterrupts();
}
public override void Execute(_MethodInfo aMethod, ILOpCode aOpCode)
{
var xStackItem = aOpCode.StackPopTypes[0];
var xSize = Math.Max(SizeOfType(xStackItem), SizeOfType(aOpCode.StackPopTypes[1]));
var xBaseLabel = GetLabel(aMethod, aOpCode);
var xNoDivideByZeroExceptionLabel = xBaseLabel + "_NoDivideByZeroException";
if (TypeIsFloat(xStackItem))
{
throw new Exception("Cosmos.IL2CPU.x86->IL->Div_Un.cs->Error: Expected unsigned integer operands but got float!");
}
if (xSize > 8)
{
throw new NotImplementedException("Cosmos.IL2CPU.x86->IL->Div_Un.cs->Error: StackSize > 8 not supported");
}
else if (xSize > 4)
{
string BaseLabel = GetLabel(aMethod, aOpCode) + ".";
string LabelShiftRight = BaseLabel + "ShiftRightLoop";
string LabelNoLoop = BaseLabel + "NoLoop";
string LabelEnd = BaseLabel + "End";
// divisor
// low
XS.Pop(ESI);
// high
XS.Pop(EDI);
XS.Xor(EAX, EAX);
XS.Or(EAX, ESI);
XS.Or(EAX, EDI);
XS.Jump(ConditionalTestEnum.NotZero, xNoDivideByZeroExceptionLabel);
XS.Call(GetLabel(ExceptionHelperRefs.ThrowDivideByZeroExceptionRef));
XS.Label(xNoDivideByZeroExceptionLabel);
// dividend
// low
XS.Pop(EAX);
// high
XS.Pop(EDX);
// set flags
XS.Or(EDI, EDI);
// if high dword of divisor is already zero, we dont need the loop
XS.Jump(ConditionalTestEnum.Zero, LabelNoLoop);
// set ecx to zero for counting the shift operations
XS.Xor(ECX, ECX);
XS.Label(LabelShiftRight);
// shift divisor 1 bit right
XS.ShiftRightDouble(ESI, EDI, 1);
XS.ShiftRight(EDI, 1);
// increment shift counter
XS.Increment(ECX);
// set flags
XS.Or(EDI, EDI);
// loop while high dword of divisor till it is zero
XS.Jump(ConditionalTestEnum.NotZero, LabelShiftRight);
// shift the dividend now in one step
// shift dividend CL bits right
XS.ShiftRightDouble(EAX, EDX, CL);
XS.ShiftRight(EDX, CL);
// so we shifted both, so we have near the same relation as original values
// divide this
XS.Divide(ESI);
// save result to stack
XS.Push(0);
XS.Push(EAX);
//TODO: implement proper derivation correction and overflow detection
XS.Jump(LabelEnd);
XS.Label(LabelNoLoop);
//save high dividend
XS.Set(ECX, EAX);
XS.Set(EAX, EDX);
// zero EDX, so that high part is zero -> reduce overflow case
XS.Xor(EDX, EDX);
// divide high part
XS.Divide(ESI);
// save high result
XS.Push(EAX);
XS.Set(EAX, ECX);
// divide low part
XS.Divide(ESI);
// save low result
XS.Push(EAX);
XS.Label(LabelEnd);
}
else
{
XS.Pop(ECX);
XS.Test(ECX, ECX);
XS.Jump(ConditionalTestEnum.NotZero, xNoDivideByZeroExceptionLabel);
XS.Call(GetLabel(ExceptionHelperRefs.ThrowDivideByZeroExceptionRef));
XS.Label(xNoDivideByZeroExceptionLabel);
XS.Pop(EAX);
XS.Xor(EDX, EDX);
XS.Divide(ECX);
XS.Push(EAX);
}
}
