This is a major portion of why I use Julia as my primary math programming language. By default it doesn't re-associate (unlike C) which makes it much easier to write error compensating arithmetic, and it has macros to make it easy on to give any function/expression fastmath semantics (or narrower re-association only semantics without the NaN/Inf/subnormal effects of fastmath. It also has a reinterpret function which makes it much simpler to do bitcasts than C where there are 100 different ways, 99% of which are technically UB.