How to use Yeppp! in Unity?

I’m currently trying to use Yeppp! (which promises SIMD-instructions to be usable in C#, thus offering potentially huge improvements in terms of speed). According to the site (, all that needs to be done is include the yeppp-clr.dll, after which you are ready to use Yeppp! within C#.

I’ve put the dll in “assets”, which is normally enough to use dll’s within Unity. However, whenever I run the code (in which I call a function from the dll), I get the error “DllNotFoundException; yeppp”. This is strange, because inside MonoDevelop, I do get function-suggestion, so MonoDevelop knows that the dll exists and is aware of its contents.

I’ve been trying to solve this problem for hours. So my question is; Can anyone get Yeppp! to work within Unity and tell me what I did wrong (the files needed can be downloaded for free at the site I just mentioned)?

Thanks in advance and please mention if you need more information, I will be happy to provide it.

Using Yeppp! with CLR languages involves two library binaries: platform-specific Yeppp! library with C interface (yeppp.dll,, or libyeppp.dylib) and platform-independent CLR wrapper (yeppp-clr.dll). Your problem is likely related to the former: Unity fails to find platform-specific binary.

Probably the easiest way to solve the problem is to copy the proper platform-specific binary to the same directory as your executable file. Another option is to add the directory with platform-specific binary to PATH variable (on Windows), LD_LIBRARY_PATH variable (on GNU/Linux and Android), or DYLD_LIBRARY_PATH variable (on Mac OS X).