Any CPU or x64 or x86

How to learn processor achitecture of an assembly ?

Powershell:

[reflection.assemblyname]::GetAssemblyName("${pwd}\Microsoft.SharePoint.dll") | fl

https://msdn.microsoft.com/tr-tr/library/system.reflection.processorarchitecture(v=vs.110).aspx

Amd64

A 64-bit AMD processor only.

Arm

An ARM processor.

IA64

A 64-bit Intel processor only.

MSIL

Neutral with respect to processor and bits-per-word. (AnyCPU)

None

An unknown or unspecified combination of processor and bits-per-word.

X86

A 32-bit Intel processor, either native or in the Windows on Windows environment on a 64-bit platform (WOW64).

Or Corflags.exe
https://docs.microsoft.com/en-us/dotnet/framework/tools/corflags-exe-corflags-conversion-tool

CPU Architecture           PE      32BITREQ   32BITPREF
 ------------------------   -----   --------   ---------
 x86 (32-bit)               PE32           1           0
 x64 (64-bit)               PE32+          0           0
 Any CPU                    PE32           0           0
 Any CPU 32-Bit Preferred   PE32           0           1

More Information:
What does Any CPU really means ?
http://blogs.microsoft.co.il/sasha/2012/04/04/what-anycpu-really-means-as-of-net-45-and-visual-studio-11/