1 files changed, 80 insertions, 0 deletions
diff --git a/gcc/testsuite/gfortran.dg/do_1.f90 b/gcc/testsuite/gfortran.dg/do_1.f90
new file mode 100644
index 000000000..171275af3
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/do_1.f90
@@ -0,0 +1,80 @@
+! { dg-do run }
+! Program to check corner cases for DO statements.
+program do_1
+  implicit none
+  integer i, j
+
+  ! limit=HUGE(i), step 1
+  j = 0
+  do i = HUGE(i) - 10, HUGE(i), 1
+    j = j + 1
+  end do
+  if (j .ne. 11) call abort
+  ! limit=HUGE(i), step > 1
+  j = 0
+  do i = HUGE(i) - 10, HUGE(i), 2
+    j = j + 1
+  end do
+  if (j .ne. 6) call abort
+  j = 0
+  do i = HUGE(i) - 9, HUGE(i), 2
+    j = j + 1
+  end do
+  if (j .ne. 5) call abort
+
+  ! Same again, but unknown loop step
+  if (test1(10, 1) .ne. 11) call abort
+  if (test1(10, 2) .ne. 6) call abort
+  if (test1(9, 2) .ne. 5) call abort
+
+  ! Zero iterations
+  j = 0
+  do i = 1, 0, 1 ! { dg-warning "executed zero times" }
+    j = j + 1
+  end do
+  if (j .ne. 0) call abort
+  j = 0
+  do i = 1, 0, 2 ! { dg-warning "executed zero times" }
+    j = j + 1
+  end do
+  if (j .ne. 0) call abort
+  j = 0
+  do i = 1, 2, -1 ! { dg-warning "executed zero times" }
+    j = j + 1
+  end do
+  if (j .ne. 0) call abort
+  call test2 (0, 1)
+  call test2 (0, 2)
+  call test2 (2, -1)
+  call test2 (2, -2)
+
+  ! Bound near smallest value
+  j = 0;
+  do i = -HUGE(i), -HUGE(i), 10
+    j = j + 1
+  end do
+  if (j .ne. 1) call abort
+contains
+! Returns the number of iterations performed.
+function test1(r, step)
+  implicit none
+  integer test1, r, step
+  integer k, n
+  k = 0
+  do n = HUGE(n) - r, HUGE(n), step
+    k = k + 1
+  end do
+  test1 = k
+end function
+
+subroutine test2 (lim, step)
+  implicit none
+  integer lim, step
+  integer k, n
+  k = 0
+  do n = 1, lim, step
+    k = k + 1
+  end do
+  if (k .ne. 0) call abort
+end subroutine
+end program