There are only 64 bit chips now, they have a 64 bit win10m, and they surely have reference hardware for 64 bit win10m otherwise they couldn't have a 64 bit win10m.
If then intention was to completely not-support 32 bit, I can't see any motive to even compile for it. Why do that at all? And why write it platform agnostic?
I don't agree that is 'entirely meaningless', as you say. At minimum it suggests that 32 bit is a possibility
If you're thinking that 32 bit builds of the Windows OS only make sense for existing smartphones running W10M (that's what it sounds like), then that would be incorrect. The entire W10 OS is available in both 32 and 64 bit "flavors" and must continue to be available in both. For example, many Atom laptops can only run 32 bit versions of Windows, so a 32 bit flavor must exist either way!
So yes, it's completely meaningless. It's always been clear (or should have been) that CShell must exist in both 32 and 64 bit "flavors", because the W10 OS CShell is being shipped with must also be available in both "flavors".
Typically there are issues in .NET, unless the code is written platform agnostic (ie designed to be able to run on both). There are things like how floating point, and pointers are handled.
Source?
I've consulted on literally hundreds of projects for both platform agnostic (which almost all .NET applications are) and platform specific projects (usually C++). I've neither seen myself, nor heard from anyone else, of issues related to the compiler targeting source code towards 32 or 64 bit systems. It's always behaved exactly as expected.
The Windows OS team works almost exclusively with C/C++. Transparently building 32 and 64 bit flavors of the Windows OS from the same source code is something they have been doing for over two decades now. The idea that CShell (a UI component that is as far removed from the low-level internals of the OS as anything can possibly be) is going to cause any issues related to bitedness sounds crazy to me.
Why write platform agnostic and compile it (and clearly test it) on a 32 bit machine?
Why write in a platform agnostic way? Ehm... because MS must. Almost the entire OS is written in a platform agnostic way and CShell is part of the OS (almost all chipset and CPU differences are encapsulated in the drivers). Besides, at this point it's actually easier to write in a platform agnostic way, as all the guidelines MS developers must follow basically force them to.
So why not compile it on a 32 bit machine? That would be the far better question. There is no difference for the CShell team either way. Whatever they write must be transparently translatable by the compiler to both 32 and 64 bit "flavors". The people working on the desktop composition of CShell will likely build 64 bit versions and test on their W10 developer machines, while the people working on the CShell composition for smaller devices will likely build 32 bit versions and test on something with a small screen, like the x3.
In fact, if anybody on the CShell team is caught developing code that specifically targets the x3 or
ANY OTHER hardware, they'd likely get into a lot of trouble (if not fired). Sprinkling hardware related issues into the UI layer would quickly become a maintenance nightmare. Any developer worth their salt knows that. CShell must be hardware agnostic! Bitedness is part of that.
Whether MS ends up testing CShell on the x3, the 950/XL, or some other continuum enabled device is completely irrelevant. If that were at any point
not true, then that would only point towards the team having unearthed a bug that must be fixed somewhere at a lower level in the OS' software stack, for example in a driver. Testing this on a more mature platform, like the x3 (rather than on reference hardware that is still in development), is a good way of avoiding that sort of thing.
Anyway, how many other devices exist that are:
- mostly stable
- support continuum
- not subject to NDA and can be shown to the public
- allow MS to test CShell on a small screen
I can't think of many devices that fit that description. Since bitedness really doesn't matter, and literally isn't allowed to, it makes perfect sense to use the x3 for that purpose. That just doesn't imply that MS is planning to release CShell for the x3. It only means that MS intends for CShell to also run on small screen's. That's all it means.