!
      program tstexp
      implicit none
!
! xlf90 -qrealsize=8 -qflttrap=inexact:enable ! core dumps on exparg=700.
! xlf90 -qrealsize=8 -qflttrap=ov:und:zero:inv:imp:enable ! no core dump
!       -qsigtrap=xl__trcedump expmax.f ! no traceback
!       -qsigtrap=xl__ieee expmax.f     ! no traceback
! Note this does not trap because exp() is a library routine.
!
! exparg=-745.13 x=exp(exparg)= 0.49406565-323
! exparg=-745.14 x=exp(exparg)= 0.00000000E+00
!
! exparg= 709.78 x=exp(exparg)= 0.17928228+309
! exparg= 709.79 x=exp(exparg)=            INF
!
      real :: x,exparg
      integer :: i

! huge(x) =  0.17976931+309
!     write(6,"('huge(x) = ',e15.8)") huge(x)
 
!     exparg =  709.7
!     exparg = -745.1
!     do i=1,10
!       x = exp(exparg)
!       write(6,"('exparg=',f7.2,' x=exp(exparg)=',e15.8)") exparg,x
!       exparg = exparg+1.
!       exparg = exparg+0.1
!       exparg = exparg+0.01
!
!       exparg = exparg-1.
!       exparg = exparg-0.1
!       exparg = exparg-0.01
!     enddo

      x = .1e81
      exparg = -8.e-21*x
      write(6,"('exparg=',e12.4,' exp(exparg)=',e12.4)")
     |  exparg,exp(exparg)
      end