I'm using the CM4 version of the RTCESL library. The function GFLIB_AtanYX_F16 has an error flag as output type which the documenation claims to be a bool_t type that is 16 bit wide.
However, it seems the routine writes a 32 bit value to the error address. I've checked this with library versions 4.4 and 4.5 - both have the same behaviour.
Could you please check if other routines of the library using the bool_t type correctly as 16 bit value.