> 0.2+0.1
0.2+0.1 with floating point numbers _is_ deterministic, as you'll always get the same answer.
I suspect you might instead mean exact calculations/answers (in the example above, neither 0.1, 0.2 nor 0.3 have exact representations using floating point numbers).
And just to be clear, there are non-determinism-like issues with floating point numbers, but those are much rarer/niche and _can_ be fixed. For example parallel summation depends on the order the summation was made, so non-determinism in the parallel implementation ripples through the summation result. Some non-basic operations (e.g. trigonometric operations) have platform dependent implementations with different roundings, so you might experience different result based on the platform you're on.