When using Win32/x86 in a version block is that the compiler or OS?

[Gary Willoughby]

On Sunday, 12 January 2014 at 19:01:05 UTC, John Colvin wrote:
> On Sunday, 12 January 2014 at 18:47:43 UTC, Gary Willoughby 
> wrote:
>> When using Win32/x86 in a version block, does that relate to 
>> the compiler or OS?
>>
>> for example:
>>
>> version(Win32)
>> {
>>    // 32bit Windows or 32bit Compiler?
>> }
>>
>> version(X86)
>> {
>>    // 32bit OS or 32bit Compiler?
>> }
>>
>> If these don't relate to the compiler is there any indication 
>> that the program is being compiled with a 32bit compiler?
>>
>> I'm primarily asking because i need to use this to constrain 
>> dub to build different things depending on what compiler is 
>> used and on what architecture.
>
> version arguments are for the target architecture, not the 
> compiler/build-environment.

Are there any for the compiler?