/// <summary>
/// Gets whether reading/writing an element of accessType from the pointer
/// is equivalent to reading/writing an element of the pointer's element type.
/// </summary>
/// <remarks>
/// The access semantics may sligthly differ on read accesses of small integer types,
/// due to zero extension vs. sign extension when the signs differ.
/// </remarks>
public static bool IsCompatibleTypeForMemoryAccess(IType pointerType, IType accessType)
{
IType memoryType;
if (pointerType is PointerType || pointerType is ByReferenceType)
{
memoryType = ((TypeWithElementType)pointerType).ElementType;
}
else
{
return(false);
}
memoryType = memoryType.AcceptVisitor(NormalizeTypeVisitor.TypeErasure);
accessType = accessType.AcceptVisitor(NormalizeTypeVisitor.TypeErasure);
if (memoryType.Equals(accessType))
{
return(true);
}
// If the types are not equal, the access still might produce equal results in some cases:
// 1) Both types are reference types
if (memoryType.IsReferenceType == true && accessType.IsReferenceType == true)
{
return(true);
}
// 2) Both types are integer types of equal size
StackType memoryStackType = memoryType.GetStackType();
StackType accessStackType = accessType.GetStackType();
if (memoryStackType == accessStackType && memoryStackType.IsIntegerType() && GetSize(memoryType) == GetSize(accessType))
{
return(true);
}
// 3) Any of the types is unknown: we assume they are compatible.
return(memoryType.Kind == TypeKind.Unknown || accessType.Kind == TypeKind.Unknown);
}
/// <summary>
/// Gets whether reading/writing an element of accessType from the pointer
/// is equivalent to reading/writing an element of the pointer's element type.
/// </summary>
/// <remarks>
/// The access semantics may sligthly differ on read accesses of small integer types,
/// due to zero extension vs. sign extension when the signs differ.
/// </remarks>
public static bool IsCompatibleTypeForMemoryAccess(IType pointerType, IType accessType)
{
IType memoryType;
if (pointerType is PointerType || pointerType is ByReferenceType)
{
memoryType = ((TypeWithElementType)pointerType).ElementType;
}
else
{
return(false);
}
if (memoryType.Equals(accessType))
{
return(true);
}
// If the types are not equal, the access still might produce equal results in some cases:
// 1) Both types are reference types
if (memoryType.IsReferenceType == true && accessType.IsReferenceType == true)
{
return(true);
}
// 2) Both types are integer types of equal size
StackType memoryStackType = memoryType.GetStackType();
StackType accessStackType = accessType.GetStackType();
return(memoryStackType == accessStackType && memoryStackType.IsIntegerType() && GetSize(memoryType) == GetSize(accessType));
}
