knc.h
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. pmulus_vi64.ispc (-O2)
The root of the broblem is in the code generator - it assumes __vec16_i64 stores its elements sequentually in memory,
not high and low parts separately as we do. Consequently, this construction works incorrectly

```
__vec16_i64 (((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t
*)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t
*)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t
*)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t *)(&tmp__2_))[0], ((uint64_t
*)(&tmp__2_))[0]
```
where 'tmp__2_' is of  __vec16_i64 data type.