http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46155
--- Comment #13 from Kalle Olavi Niemitalo <kon at iki dot fi> 2010-11-18 08:10:20 UTC --- Earlier, I thought GCC would eventually have to add some libc-specific definitions to <float.h> anyway, in order to make FLT_ROUNDS call a function in the C library and map the results correctly, and the IBM fprnd_t and function declarations could then be added at the same time; but according to bug 30569, FLT_ROUNDS is supposed to call a built-in function instead. FLT_EVAL_METHOD has a similar "???" comment above it, but C99 says it shall be a "constant expression[s] suitable for use in #if preprocessing directives", so cannot expand to a function call.
