--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java Mon Oct 13 17:22:47 2014 +0200
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java Mon Oct 13 12:12:06 2014 -0400
@@ -1225,8 +1225,8 @@
// consider the size of the bytecode.
// A discussion of the metric can be found here:
// http://mail.openjdk.java.net/pipermail/compiler-dev/2014-September/008987.html
- int table_cost = 4 + (hi - lo + 1); // words
- int lookup_cost = 3 + 2 * nlabels;
+ long table_cost = 4 + ((long)hi - lo + 1); // words
+ long lookup_cost = 3 + 2 * (long)nlabels;
int opcode = table_cost <= lookup_cost ? tableswitch : lookupswitch;
int startpc = code.curCP(); // the position of the selector operation
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/SwitchMetricTest.java Mon Oct 13 12:12:06 2014 -0400
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2014, 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 8058243
+ * @summary Reduce size of bytecode for large switch statements
+ * @library /tools/lib
+ * @build ToolBox
+ * @run main SwitchMetricTest
+ */
+
+import java.net.URL;
+import java.util.List;
+
+public class SwitchMetricTest {
+ public static void main(String... args) throws Exception {
+ new SwitchMetricTest().run();
+ }
+
+ // This code should produce a tableswitch
+ class Test1 {
+ int m(int x) {
+ switch (x) {
+ case 1:
+ case 2:
+ case 3:
+ case 4:
+ case 5: return 1;
+ default: return 0;
+ }
+ }
+ }
+
+ // This code should produce a lookupswitch
+ class Test2 {
+ int m(int x) {
+ switch (x) {
+ case 1:
+ case 2:
+ case 3:
+ case 4:
+ case 50: return 1;
+ default: return 0;
+ }
+ }
+ }
+
+ void check(String classfile, String bytecode) throws Exception {
+ ToolBox tb = new ToolBox();
+ URL url = SwitchMetricTest.class.getResource(classfile);
+ List<String> result = tb.new JavapTask()
+ .options("-c")
+ .classes(url.getFile())
+ .run()
+ .write(ToolBox.OutputKind.DIRECT)
+ .getOutputLines(ToolBox.OutputKind.DIRECT);
+
+ List<String> matches = tb.grep(bytecode, result);
+ if (matches.isEmpty())
+ throw new Exception(bytecode + " not found");
+ }
+
+ void run() throws Exception {
+ check("SwitchMetricTest$Test1.class", "tableswitch");
+ check("SwitchMetricTest$Test2.class", "lookupswitch");
+ }
+}