Use of !DEC$ATTRIBUTES FORCEINLINE

I read round the help files which do not say very much and had a some (hopefully) quick question.

1] Is the sample below valid usage of the directive?

2] Having use  FORCEINLINE in a subroutine that is called from multiple locations I expected to see an increase in my .exe size but there is no change. Is my expection wrong?

3] would some  build option cause  FORCEINLINE to be ignored?

4] Any other comments or suggestions, the object was to make hacking/code patching more difficult

subroutine myfunc( istat, kbuf1)
!DEC$ATTRIBUTES FORCEINLINE :: myfunc
use mymod
integer(4) :: istat
integer(1) :: kbuf1(1)

!code
!code
!code

return
end