gfortran linker argument for library containing IEEE_GET_ROUNDING_MODE - fortran

Question

I'm trying to write a simple Fortran library for interval arithmetic as an exercise. I want to explicitly set the rounding mode, do some work, and then restore the rounding mode to what it was originally. However, I can't figure out which library needs to be linked to resulting executable when compiling with gfortran, gcc's Fortran frontend.
! get_rounding_mode.f03
! print the rounding mode
program get_rounding_mode
f = IEEE_GET_ROUNDING_MODE()
print *,f
end program get_rounding_mode
Trying the Simplest Thing That Could Possibly Work gives me
gfortran get_rounding_mode.f03
/usr/bin/ld: /tmp/ccTLaxeN.o: in function `MAIN__':
get_rounding_mode.f03:(.text+0x20): undefined reference to `ieee_get_rounding_mode_'
collect2: error: ld returned 1 exit status
Exit 1
By looking everywhere for ieee_get_rounding I found it, but I don't know how to direct gfortran to link it since it appears to already be in libgfortran .
find /usr/ -exec nm --print-file-name '{}' '+' 2>&1 | grep 'ieee_get_rounding'
/usr/lib/libgfortran.so.5:000000000023edc0 T __ieee_arithmetic_MOD_ieee_get_rounding_mode
/usr/lib/libgfortran.so:000000000023edc0 T __ieee_arithmetic_MOD_ieee_get_rounding_mode

Answer 1

IEEE_GET_ROUNDING_MODE isn't a function. It is a subroutine. You need to do something like
program get_rounding_mode
use ieee_arithmetic
implicit none
ieee_rounding_type mode
real x
if (ieee_support_rounding(x)) then
call ieee_get_rounding_mode(mode) ! Get current rounding mode
call ieee_set_rounding_mode(IEEE_TO_UP) ! Set rounding up
!
! Do your work here!
!
call ieee_set_rounding_mode(mode) ! Reset rounding mode
end if
end program get_rounding_mode
Whoops, forgot the implicit none and declaration of x