This enables three additional math optimizations:
-ffp-contract=fast (enables FMA generation)
-freciprocal-math (enables x/y -> x*(1/y))
-fassociative-math (enables e.g. a*b + c*b -> (a+c)*b)
These are used on Windows and HIP anyways, so our code can't expect exact IEEE
semantics in any case.
The only difference between the new set and -ffast-math is that we don't use
-ffinite-math-only since this causes issues with the BVH (see ce1f2e271d) and
breaks e.g. isnan.
This causes a ~1.5% speedup in my very quick test, but might be higher for some
more math-intensive cases.
Pull Request: https://projects.blender.org/blender/blender/pulls/128342
f96f3c33af