This intrinsic inserts a SHSUB8 instruction into the instruction stream generated by the compiler. It enables you to perform four signed 8-bit integer subtractions, halving the results.

unsigned int __shsub8(unsigned int val1, unsigned int val2)

where:

The __shsub8 intrinsic returns:

Example:

unsigned int subtract_and_halve(unsigned int val1, unsigned int val2)
{
  unsigned int res;

    res = __shsub8(val1,val2); /* res[7:0] = (val1[7:0] - val2[7:0]) >> 1
                                  res[15:8] = (val1[15:8] - val2[15:8]) >> 1
                                  res[23:16] = (val1[23:16] - val2[23:16] >> 1
                                  res[31:24] = (val1[31:24] - val2[31:24] >> 1
                                */
    return res;
}