We start with the simple scalar operations given by
for (i = 0; i < n; i++){
a[i] = b[i] + c[i];
}
If the code is not vectorized and we have a 128-bit register to store a 32 bits floating point number, it means that we have \( 3\times 32 \) bits that are not used.
We have thus unused space in our SIMD registers. These registers could hold three additional integers.