[CMake] How to use different assemblers in single build?

[Alexey Istomin]

> Yes.
> You need to duse two different assembler "dialects", each "dialect" counts as a separate language to cmake, so you can have many in parallel.
> So you should add e.g. a ASM-DSP dialect, and set the language of the source files to ASM-DSP.
> This this assembler will be invoked on these files.
> Adding an assembler dialect is not hard, you need just a few tiny files:
> http://www.cmake.org/Wiki/CMake/Assembler
> This page is slightly out of date, but the documentation how to add a new assembler is still valid.
> Just have a look at the Modules/ directory for the ASM-related files, you should see how this works.
>
> Alex

Thanks a lot, Alex.
I done some experiments. It looks like dsp-asm sources should have a different file extension? 
Can CMake select specific asm-compiler depends on subdir instead of file extesion?