error: Undefined Behavior: `fsub_fast` intrinsic called with non-finite value as both parameters
  --> $DIR/fast_math_both.rs:LL:CC
   |
LL | ...: f32 = core::intrinsics::fsub_fast(f32::NAN, f32::NAN);
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `fsub_fast` intrinsic called with non-finite value as both parameters
   |
   = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
   = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
           
   = note: inside `main` at $DIR/fast_math_both.rs:LL:CC

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to previous error