[hsa] Add missing guard in OMP gridification

2017-10-30  Martin Jambor  <mjambor@suse.cz>

	* omp-grid.c (grid_attempt_target_gridification): Also insert a
	condition whether loop should be executed at all.

From-SVN: r254225

gcc/ChangeLog

+2017-10-30  Martin Jambor  <mjambor@suse.cz>
+
+	* omp-grid.c (grid_attempt_target_gridification): Also insert a
+	condition whether loop should be executed at all.
+
 2017-10-30  Will Schmidt  <will_schmidt@vnet.ibm.com>
 
 	* config/rs6000/rs6000.c (rs6000_gimple_fold_builtin): Add support for

gcc/omp-grid.c

@@ -1315,6 +1315,7 @@ grid_attempt_target_gridification (gomp_target *target,
       n1 = fold_convert (itype, n1);
       n2 = fold_convert (itype, n2);
 
+      tree cond = fold_build2 (cond_code, boolean_type_node, n1, n2);
       tree step
 	= omp_get_for_step_from_incr (loc, gimple_omp_for_incr (inner_loop, i));
 
@@ -1328,6 +1329,7 @@ grid_attempt_target_gridification (gomp_target *target,
 			 fold_build1 (NEGATE_EXPR, itype, step));
       else
 	t = fold_build2 (TRUNC_DIV_EXPR, itype, t, step);
+      t = fold_build3 (COND_EXPR, itype, cond, t, build_zero_cst (itype));
       if (grid.tiling)
 	{
 	  if (cond_code == GT_EXPR)