On: Your C is not standard C

[dzaima]

> gcc, however, always defines FLT_ROUNDS to 1

Well, considering that gcc doesn't support the FENV_ACCESS pragma, and as such all fesetround calls are always UB, it is valid for it to act as if the rounding mode never changes from the default :)

[uecker → dzaima]

Well, it is not ok to not support FENV_ACCESS though.

[amszmidt → uecker]

I skimmed the standard and POSIX, but couldn’t find anything that an implementation is required to support FENV_ACCESS.