This intrinsic inserts an SXTB16 instruction into the instruction stream generated by the compiler. It enables you to extract two 8-bit values from an operand and sign-extend them to 16 bits each.

unsigned int __sxtb16(unsigned int val)

where val[7:0] and val[23:16] hold the two 8-bit values to be sign-extended.

The __sxtb16 intrinsic returns the 8-bit values sign-extended to 16-bit values.

Example:

unsigned int sign_extend(unsigned int val)
{
  unsigned int res;

    res = __sxtb16(val1,val2); /* res[15:0] = SignExtended(val[7:0]
                                  res[31:16] = SignExtended(val[23:16]
                                */
    return res;
}