int16x2 __uxtab16(int16x2 val1, uint8x4 val2);

**__uxtab16** inserts a UXTAB16 instruction. **__uxtab16** returns the 16-bit unsigned equivalent of

- res[0] = val1[0] + (unsigned short)val2[0]
- res[1] = val1[1] + (unsigned short)val2[2]

where res[0] & val1[0] are the lower 16 bits, res[1] & val1[1] are the upper 16 bits, val2[0] is the lower 8 bits and val2[2] is the 8 bits starting at bit position 16.