[AArch64] Remember to cost operand 0 in FP compare-with-0.0 case

* config/aarch64/aarch64.c (aarch64_rtx_costs, COMPARE case):
	Add cost of op0 in the compare-with-fpzero case.

From-SVN: r222673

gcc/ChangeLog

@@ -1,3 +1,8 @@
+2015-05-01  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/aarch64/aarch64.c (aarch64_rtx_costs, COMPARE case):
+	Add cost of op0 in the compare-with-fpzero case.
+
 2015-04-30  David Malcolm  <dmalcolm@redhat.com>
 
 	* builtins.c (fold_builtin_1): Remove spurious second

gcc/config/aarch64/aarch64.c

@@ -5865,6 +5865,7 @@ aarch64_rtx_costs (rtx x, int code, int outer ATTRIBUTE_UNUSED,
 
           if (CONST_DOUBLE_P (op1) && aarch64_float_const_zero_rtx_p (op1))
             {
+              *cost += rtx_cost (op0, COMPARE, 0, speed);
               /* FCMP supports constant 0.0 for no extra cost. */
               return true;
             }