expr.c (expand_expr_real_2): Re-cost if previous costs are the same.

2017-04-26  Tamar Christina  <tamar.christina@arm.com>

	* expr.c (expand_expr_real_2): Re-cost if previous costs are the same.

From-SVN: r247505

1 files changed, 9 insertions, 0 deletions

diff --git a/gcc/expr.c b/gcc/expr.c
index c5c50e0..4749cc5 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -8838,6 +8838,15 @@ expand_expr_real_2 (sepops ops, rtx target, machine_mode tmode,
 	   end_sequence ();
 	   unsigned uns_cost = seq_cost (uns_insns, speed_p);
 	   unsigned sgn_cost = seq_cost (sgn_insns, speed_p);
+
+	   /* If costs are the same then use as tie breaker the other
+	      other factor.  */
+	   if (uns_cost == sgn_cost)
+	     {
+		uns_cost = seq_cost (uns_insns, !speed_p);
+		sgn_cost = seq_cost (sgn_insns, !speed_p);
+	     }
+
 	   if (uns_cost < sgn_cost || (uns_cost == sgn_cost && unsignedp))
 	     {
 	       emit_insn (uns_insns);