[PATCH] Fix fortran/openmp.c collapsed loop analysis (PR fortran/85313)

[Jakub Jelinek]

Hi!

Dunno what I was thinking when adding this if (j < i) break;, with it we
never verify whether second and following loop iterators aren't used in
third and following loops in collapse(3) and above loops.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
committed to trunk.

2018-04-10  Jakub Jelinek  <ja...@redhat.com>

        PR fortran/85313
        * openmp.c (resolve_omp_do): Remove bogus if (j < i) break;.
        (resolve_oacc_nested_loops): Likewise.  Formatting fix.

        * gfortran.dg/gomp/pr85313.f90: New test.

--- gcc/fortran/openmp.c.jj     2018-01-31 21:47:18.774155978 +0100
+++ gcc/fortran/openmp.c        2018-04-10 12:21:38.371945086 +0200
@@ -5600,8 +5600,6 @@ resolve_omp_do (gfc_code *code)
                             "iteration space at %L", name, &do_code->loc);
                  break;
                }
-             if (j < i)
-               break;
              do_code2 = do_code2->block->next;
            }
        }
@@ -5765,12 +5763,10 @@ resolve_oacc_nested_loops (gfc_code *cod
                  || gfc_find_sym_in_expr (ivar, do_code->ext.iterator->end)
                  || gfc_find_sym_in_expr (ivar, do_code->ext.iterator->step))
                {
-                 gfc_error ("!$ACC LOOP %s loops don't form rectangular 
iteration space at %L",
-                            clause, &do_code->loc);
+                 gfc_error ("!$ACC LOOP %s loops don't form rectangular "
+                            "iteration space at %L", clause, &do_code->loc);
                  break;
                }
-             if (j < i)
-               break;
              do_code2 = do_code2->block->next;
            }
        }
--- gcc/testsuite/gfortran.dg/gomp/pr85313.f90.jj       2018-04-10 
12:14:54.438779463 +0200
+++ gcc/testsuite/gfortran.dg/gomp/pr85313.f90  2018-04-10 12:13:46.975751804 
+0200
@@ -0,0 +1,25 @@
+! PR fortran/85313
+! { dg-do compile }
+
+!$omp do collapse(3)
+  do i = 1, 10
+    do j = i, 20       ! { dg-error "form rectangular iteration space" }
+      do k = 1, 2
+      end do
+    end do
+  end do
+!$omp do collapse(3)
+  do i = 1, 10
+    do j = 1, 5
+      do k = i, 20     ! { dg-error "form rectangular iteration space" }
+      end do
+    end do
+  end do
+!$omp do collapse(3)
+  do i = 1, 10
+    do j = 1, 5
+      do k = j, 20     ! { dg-error "form rectangular iteration space" }
+      end do
+    end do
+  end do
+end

        Jakub