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

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 00f21e7..b177645 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2017-04-26  Tamar Christina  <tamar.christina@arm.com>
+
+       * expr.c (expand_expr_real_2): Re-cost if previous costs are the same.
+
 2017-04-27  Tamar Christina  <tamar.christina@arm.com>
 
        * simplify-rtx.c (simplify_binary_operation_1): Add LSHIFTRT case.

diff --git a/gcc/expr.c b/gcc/expr.c
index c5c50e0..4749cc5 100644 (file)
--- 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);