no longer builds for any architecture except x86

Commit 8de231568b7c43c7672f9e508c308d9bc715d120 broke the build for all non-x86 architectures. The offending code is this:

```
#ifndef __SSE_MATH__
    __asm__ __volatile__ ( "emms");
#endif
```

Changing it to

```
#ifdef __MMX__
    __asm__ __volatile__ ( "emms");
#endif
```

(similar to how things are done in alg.c) restores the build for all platforms.

I have added this to pull request #16.
