This function returns the address of the floating-point status
register.
Syntax
unsigned* _rt_fp_status_addr(void);
Implementation
If __rt_fp_status_addr() is not defined,the
default implementation from the C library is used. The value is
initialized when __rt_lib_init() calls _fp_init().
The constants for the status word are listed in fenv.h.
The default fp status is 0.