GCC has some support for fixed-point arithmetic, as an extension to the C language. Unfortunately only a very few target architectures are supported, not including AMD64. [0] (Unfortunately this page doesn't list which architectures are supported.)
As carlmr mentioned, the Ada language has built-in support for fixed-point arithmetic types.
As carlmr mentioned, the Ada language has built-in support for fixed-point arithmetic types.
[0] https://gcc.gnu.org/onlinedocs/gcc/Fixed-Point.html