The guarantees could be provided, if there would be a way to ensure that the compiler uses the same standard math library that is used by the executable program that is created.
This could be done, for instance, if the standard math library would be dynamically linked into the compiler, so the same library would be available for the compiled program.
If you disregard performance, yes. Unfortunately forcing softfloat everywhere would result in abysmal performance, so this is not an option.