fix sfloat_v to ushort_v casts - much more efficient with SSE4.1, though
fix sfloat_v to ushort_v casts - much more efficient with SSE4.1, though

chr-engwer/Vc,chr-engwer/Vc,VcDevel/Vc,VcDevel/Vc,VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc