FLT_ROUNDS not always 1?

[Stan Shebs]

The C99 standard specifies that the value of FLT_ROUNDS in float.h
has an implementation-defined value that should reflect the result
of fesetround().  However, all the float-*.h in gcc/config set
FLT_ROUNDS to 1 unconditionally, irrespective of whether the target
is a system that defines fesetround.

Is it really the case that for all GCC targets, fesetround() is
a no-op that always returns 1?  Or is it just that systems that
implement fesetround need to have their own config/float-foo.h that
defines FLT_ROUNDS in a non-constant way, and no one has done this
correctly yet?

Stan