That's very much an issue with SIMD, especially where floating point numbers are concerned.

Matt Godbolt wrote about it recently.

https://xania.org/202512/21-vectorising-floats

TLDR, math notation and language specify particular orders in which floating point operations happen, and precision limits of IEEE float representation mean those have to be honoured by default.

Allowing compilers to reorder things in breach of that contract is an option, but it comes with risks.