gcc/testsuite/gfortran.dg/implied_do_io_6.f90

   1 ! { dg-do  run }
   2 ! { dg-options "-ffrontend-optimize" }
   3 ! PR 86837 - this was mis-optimized by trying to turn this into an
   4 ! array I/O statement.
   5 ! Original test case by "Pascal".
   6
   7 Program read_loop
   8
   9   implicit none
  10
  11   integer :: i, j
  12
  13   ! number of values per column
  14   integer, dimension(3) :: nvalues
  15   data nvalues / 1, 2, 4 /
  16
  17   ! values in a 1D array
  18   real, dimension(7) :: one_d
  19   data one_d / 1,   11, 12,   21, 22, 23, 24 /
  20
  21   ! where to store the data back
  22   real, dimension(4, 3) :: two_d
  23
  24   ! 1 - write our 7 values in one block
  25   open(unit=10, file="loop.dta", form="unformatted")
  26   write(10) one_d
  27   close(unit=10)
  28
  29   ! 2 - read them back in chosen cells of a 2D array
  30   two_d = -9
  31   open(unit=10, file="loop.dta", form="unformatted", status='old')
  32   read(10) ((two_d(i,j), i=1,nvalues(j)), j=1,3)
  33   close(unit=10, status='delete')
  34
  35   ! 4 - print the whole array, just in case
  36
  37   if (any(reshape(two_d,[12]) /= [1.,-9.,-9.,-9.,11.,12.,-9.,-9.,21.,22.,23.,24.])) call abort
  38
  39 end Program read_loop