Deploy DLL for ARM64 and AMD64 in the same PATH?

[Jeremy Drake]

On Wed, 3 Sep 2025, Mark Liam Brown via Cygwin wrote:

> Greetings
>
> Our software needs a 3rd party DLL (we cannot change the name...), but
> we want to support ARM64 together with AMD64.
>
> Does Windows or Cygwin have a mechanism to deal with the situation
> that both expects the DLL to be in the same path?

Not really.  The closest thing is ARM64EC and ARM64X, a DLL built with
those will let you use the same DLL for both ARM64 and x64, but only on
ARM64.  I know there has been work to support those in LLVM/LLD and
mingw-w64, don't know about gcc/binutils support.

I think they expect the installer to decide which type of DLL to install
based on the host machine...