7110586: C2 generates incorrect results
Summary: Exact limit of empty loop calculated incorrectly.
Reviewed-by: iveresov, never
--- a/hotspot/src/share/vm/opto/loopnode.cpp Thu Nov 10 04:46:08 2011 -0800
+++ b/hotspot/src/share/vm/opto/loopnode.cpp Thu Nov 10 20:17:05 2011 -0800
@@ -715,7 +715,6 @@
long limit_con = cl->limit()->get_int();
julong trip_cnt = cl->trip_count();
long final_con = init_con + trip_cnt*stride_con;
- final_con -= stride_con;
int final_int = (int)final_con;
// The final value should be in integer range since the loop
// is counted and the limit was checked for overflow.
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/7110586/Test7110586.java Thu Nov 10 20:17:05 2011 -0800
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+/**
+ * @test
+ * @bug 7110586
+ * @summary C2 generates icorrect results
+ *
+ * @run main/othervm -Xbatch Test7110586
+ */
+
+public class Test7110586 {
+ static int test1() {
+ int i = 0;
+ for ( ; i < 11; i+=1) {}
+ return i;
+ }
+ static int test2() {
+ int i = 0;
+ for ( ; i < 11; i+=2) {}
+ return i;
+ }
+ static int test3() {
+ int i = 0;
+ for ( ; i < 11; i+=3) {}
+ return i;
+ }
+ static int test11() {
+ int i = 0;
+ for ( ; i < 11; i+=11) {}
+ return i;
+ }
+
+ static int testm1() {
+ int i = 0;
+ for ( ; i > -11; i-=1) {}
+ return i;
+ }
+ static int testm2() {
+ int i = 0;
+ for ( ; i > -11; i-=2) {}
+ return i;
+ }
+ static int testm3() {
+ int i = 0;
+ for ( ; i > -11; i-=3) {}
+ return i;
+ }
+ static int testm11() {
+ int i = 0;
+ for ( ; i > -11; i-=11) {}
+ return i;
+ }
+
+ public static void main(String args[]) {
+ int x1 = 0;
+ int x2 = 0;
+ int x3 = 0;
+ int x11 = 0;
+ int m1 = 0;
+ int m2 = 0;
+ int m3 = 0;
+ int m11 = 0;
+ for (int i=0; i<10000; i++) {
+ x1 = test1();
+ x2 = test2();
+ x3 = test3();
+ x11 = test11();
+ m1 = testm1();
+ m2 = testm2();
+ m3 = testm3();
+ m11 = testm11();
+ }
+ boolean failed = false;
+ if (x1 != 11) {
+ System.out.println("ERROR (incr = +1): " + x1 + " != 11");
+ failed = true;
+ }
+ if (x2 != 12) {
+ System.out.println("ERROR (incr = +2): " + x2 + " != 12");
+ failed = true;
+ }
+ if (x3 != 12) {
+ System.out.println("ERROR (incr = +3): " + x3 + " != 12");
+ failed = true;
+ }
+ if (x11 != 11) {
+ System.out.println("ERROR (incr = +11): " + x11 + " != 11");
+ failed = true;
+ }
+ if (m1 != -11) {
+ System.out.println("ERROR (incr = -1): " + m1 + " != -11");
+ failed = true;
+ }
+ if (m2 != -12) {
+ System.out.println("ERROR (incr = -2): " + m2 + " != -12");
+ failed = true;
+ }
+ if (m3 != -12) {
+ System.out.println("ERROR (incr = -3): " + m3 + " != -12");
+ failed = true;
+ }
+ if (m11 != -11) {
+ System.out.println("ERROR (incr = -11): " + m11 + " != -11");
+ failed = true;
+ }
+ if (failed) {
+ System.exit(97);
+ }
+ }
+}