public static Operand EmitLoadExclusive(ArmEmitterContext context, Operand address, bool exclusive, int size)
{
if (exclusive)
{
Operand value;
if (size == 4)
{
Operand isUnalignedAddr = InstEmitMemoryHelper.EmitAddressCheck(context, address, size);
Operand lblFastPath = Label();
context.BranchIfFalse(lblFastPath, isUnalignedAddr);
// The call is not expected to return (it should throw).
context.Call(typeof(NativeInterface).GetMethod(nameof(NativeInterface.ThrowInvalidMemoryAccess)), address);
context.MarkLabel(lblFastPath);
// Only 128-bit CAS is guaranteed to have a atomic load.
Operand physAddr = InstEmitMemoryHelper.EmitPtPointerLoad(context, address, null, write: false);
Operand zero = context.VectorZero();
value = context.CompareAndSwap(physAddr, zero, zero);
}
else
{
value = InstEmitMemoryHelper.EmitReadIntAligned(context, address, size);
}
Operand arg0 = context.LoadArgument(OperandType.I64, 0);
Operand exAddrPtr = context.Add(arg0, Const((long)NativeContext.GetExclusiveAddressOffset()));
Operand exValuePtr = context.Add(arg0, Const((long)NativeContext.GetExclusiveValueOffset()));
context.Store(exAddrPtr, context.BitwiseAnd(address, Const(address.Type, GetExclusiveAddressMask())));
// Make sure the unused higher bits of the value are cleared.
if (size < 3)
{
context.Store(exValuePtr, Const(0UL));
}
if (size < 4)
{
context.Store(context.Add(exValuePtr, Const(exValuePtr.Type, 8L)), Const(0UL));
}
// Store the new exclusive value.
context.Store(exValuePtr, value);
return(value);
}
else
{
return(InstEmitMemoryHelper.EmitReadIntAligned(context, address, size));
}
}
public static Operand EmitLoadExclusive(ArmEmitterContext context, Operand address, bool exclusive, int size)
{
if (exclusive)
{
Operand value;
if (size == 4)
{
// Only 128-bit CAS is guaranteed to have a atomic load.
Operand physAddr = InstEmitMemoryHelper.EmitPtPointerLoad(context, address, null, write: false, 4);
Operand zero = context.VectorZero();
value = context.CompareAndSwap(physAddr, zero, zero);
}
else
{
value = InstEmitMemoryHelper.EmitReadIntAligned(context, address, size);
}
Operand arg0 = context.LoadArgument(OperandType.I64, 0);
Operand exAddrPtr = context.Add(arg0, Const((long)NativeContext.GetExclusiveAddressOffset()));
Operand exValuePtr = context.Add(arg0, Const((long)NativeContext.GetExclusiveValueOffset()));
context.Store(exAddrPtr, context.BitwiseAnd(address, Const(address.Type, GetExclusiveAddressMask())));
// Make sure the unused higher bits of the value are cleared.
if (size < 3)
{
context.Store(exValuePtr, Const(0UL));
}
if (size < 4)
{
context.Store(context.Add(exValuePtr, Const(exValuePtr.Type, 8L)), Const(0UL));
}
// Store the new exclusive value.
context.Store(exValuePtr, value);
return(value);
}
else
{
return(InstEmitMemoryHelper.EmitReadIntAligned(context, address, size));
}
}
