Why does this code execute more slowly after strength-reducing multiplications to loop-carried additions?

I was reading Agner Fog's optimization manuals, and I came across this example: double data[LEN]; void compute() { const double A = 1.1, B = 2.2, C = 3.3; int i; for(i=0; i<LEN; i++) { data[i] = A*i*i + B*i + C; } } Agner indicates that there's a way to optimize this code - by realizing that the loop can avoid using costly multiplications, and instead use the "deltas" that are applied per iteratio

[htsnul]

https://news.ycombinator.com/item?id=31549050