Why is the Qt Creator for Windows built on MSVC 2015, 32-bit?

TaShot

Qt Creator on "about" states that it was built on Qt 5.12.0, on MSVC 2015, 32-bit.
I was wondering how they chose MSVC 2015 and especially the 32-bit version.
Would performance and stability be greater, same, or worse on e.g. MSVC 2017, 64-bit?

jsulm

@TaShot That you should ask QtCreator devs on the mailing list. I think the idea to use 32bit compiler to build QtCreator is simply to support both 32bit and 64bit Windows. Going for 64bit build of QtCreator would exclude 32bit Windows users and hardy provide any advantages.

JonB

@TaShot
Further to @jsulm's answer, Microsoft Visual Studio is similarly still 32-bit-only, doubtless for the same sort of reasons. "MSVC 2017, 64-bit" is only 64-bit in the compiler tool chain (like Qt Creator), not the IDE itself. A discussion is at https://stackoverflow.com/questions/2516436/visual-studio-64-bit if you're interested in the "why".

OOI, a completely separate question is why Qt Creator is built with MSVC at all? Since presumably it is built with gcc under Linux, certainly not MSVC, and since presumably it is written to use Qt for its GUI, I would have thought it would have made more sense to stick to one common compiler, but there you are....

TaShot

Thanks @jsulm, your answer pretty much covered my question.

@JonB When I start building projects I'm always perplexed as to whether I should use MinGW (for Linux compatibility), 32-bit (for 32-bit compatibility). Regarding Visual Studio, you raised a very interesting argument. Maybe building heavy applications with lots of data structures on 64-bit places more overhead on the system, due to filling the cache and RAM. I won't jump to any conclusions, as the compiler choice seems application-specific, and I'll have to thank you for providing extra food for thought.