I’m working with statistic functions with a lot of float data. I want it to run faster but Ofast disable NAN (fno-finite-math-only flag), which is not allowed in my case.
In this case, is it safe to turn on only associative-math ? I think this flag allows things like vectorized sum of vector array, even if the array contains NAN.
>Solution :
From the docs:
NOTE: re-ordering may change the sign of zero as well as ignore NaNs
So if you want correct handling of NaNs, you should not use -fassociative-math.