[openacc] Fix ICE when compiling tile loop containing infinite loop

2018-04-16  Cesar Philippidis  <cesar@codesourcery.com>
	    Tom de Vries  <tom@codesourcery.com>

	PR middle-end/84955
	* omp-expand.c (expand_oacc_for): Add dummy false branch for
	tiled basic blocks without omp continue statements.

	* testsuite/libgomp.oacc-c-c++-common/pr84955.c: New test.
	* testsuite/libgomp.oacc-fortran/pr84955.f90: New test.

Co-Authored-By: Tom de Vries <tom@codesourcery.com>

From-SVN: r259406

gcc/ChangeLog

+2018-04-16  Cesar Philippidis  <cesar@codesourcery.com>
+	    Tom de Vries  <tom@codesourcery.com>
+
+	PR middle-end/84955
+	* omp-expand.c (expand_oacc_for): Add dummy false branch for
+	tiled basic blocks without omp continue statements.
+
 2018-04-16  Aaron Sawdey  <acsawdey@linux.ibm.com>
 
 	PR target/83660

gcc/omp-expand.c

@@ -5439,6 +5439,14 @@ expand_oacc_for (struct omp_region *region, struct omp_for_data *fd)
 
 	  split->flags ^= EDGE_FALLTHRU | EDGE_TRUE_VALUE;
 
+	  /* Add a dummy exit for the tiled block when cont_bb is missing.  */
+	  if (cont_bb == NULL)
+	    {
+	      edge e = make_edge (body_bb, exit_bb, EDGE_FALSE_VALUE);
+	      e->probability = profile_probability::even ();
+	      split->probability = profile_probability::even ();
+	    }
+
 	  /* Initialize the user's loop vars.  */
 	  gsi = gsi_start_bb (elem_body_bb);
 	  expand_oacc_collapse_vars (fd, true, &gsi, counts, e_offset);

libgomp/ChangeLog

+2018-04-16  Cesar Philippidis  <cesar@codesourcery.com>
+	    Tom de Vries  <tom@codesourcery.com>
+
+	PR middle-end/84955
+	* testsuite/libgomp.oacc-c-c++-common/pr84955.c: New test.
+	* testsuite/libgomp.oacc-fortran/pr84955.f90: New test.
+
 2018-04-12  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/83064

libgomp/testsuite/libgomp.oacc-c-c++-common/pr84955.c

+/* { dg-do compile }  */
+
+int
+main (void)
+{
+  int i, j;
+
+#pragma acc parallel loop tile(2,3)
+  for (i = 1; i < 10; i++)
+    for (j = 1; j < 10; j++)
+      for (;;)
+	;
+
+  return i + j;
+}

libgomp/testsuite/libgomp.oacc-fortran/pr84955.f90

+! { dg-do compile }
+
+subroutine s
+   integer :: i, j
+   !$acc parallel loop tile(2,3)
+   do i = 1, 10
+      do j = 1, 10
+         do
+         end do
+      end do
+   end do
+  !$acc end parallel loop
+end subroutine s