gcc/testsuite/gfortran.dg/quad_3.f90

   1 ! { dg-do run }
   2 !
   3 ! I/O test for REAL(16)
   4 !
   5 ! Contributed by Dominique d'Humieres
   6 !
   7 program test_qp
   8    use iso_fortran_env, only: real_kinds
   9    implicit none
  10    integer, parameter :: QP = real_kinds(ubound(real_kinds,dim=1))
  11    real(kind=qp) :: a,b(2), c
  12    integer :: exponent, i
  13    character(len=180) :: tmp
  14
  15    ! Run this only with libquadmath; assume that all those systems
  16    ! have also kind=10.
  17    if (size (real_kinds) >= 4 .and. qp == 16) then
  18      i = 3
  19      if (real_kinds(i) /= 10) stop
  20
  21      exponent = 4000
  22      b(:) = huge (1.0_qp)/10.0_qp**exponent
  23 !     print *, 'real(16) big value:      ', b(1)
  24      write (tmp, *) b
  25      read (tmp, *) a, c
  26 !     print *, 'same value read again:   ', a, c
  27 !     print *, 'difference: looks OK now ', a-b(1)
  28      if (abs (a-b(1))/a > epsilon(0.0_qp) &
  29          .or. abs (c-b(1))/c > epsilon (0.0_qp)) call abort()
  30    end if
  31 end program test_qp