Notices by Chris Green (aachrisg@mastodon.gamedev.place)

D-oh:

std:fma will generate the fused multiply add instruction in MSVC and GCC, regardless of the setting of fp:precise as you would hope..

But MSVC doesn't know how to auto vectorize it, which kind of defeats the purpose :-( :-(. GCC does though (as does Clang):

https://godbolt.org/z/4f91hWKEE