--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gfortran.dg/dependency_21.f90	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,21 @@
+! { dg-do run }
+! Test the fix for PR31711 in which the dependency in the assignment
+! at line 18 was detected and then ignored.
+!
+! Contributed by Tobias Ivarsson <thobes@gmail.com>
+!
+program laplsolv
+  IMPLICIT NONE
+  integer, parameter                  :: n = 2
+  double precision,dimension(0:n+1, 0:n+1) :: T
+  integer                             :: i
+
+  T=0.0
+  T(0:n+1 , 0)     = 1.0
+  T(0:n+1 , n+1)   = 1.0
+  T(n+1   , 0:n+1) = 2.0
+
+  T(1:n,1)=(T(0:n-1,1)+T(1:n,1+1)+1d0)
+
+  if (any (T(1:n,1) .ne. 1d0 )) call abort ()
+end program laplsolv