Mercurial > hg > truffle
view test/compiler/EscapeAnalysis/Test8020215.java @ 11825:463f51256c86
AMD64HotSpot: emit jump to IC miss handler directly instead of emitting it inside verfied_entry
for empty methods we emitted something like this if a inline cache is needed:
prefix:
00: < IC check >
...
0b: jne <ic_miss_call>
11: nop
...
verified_entry:
20: ret
ic_miss_call:
21: jmp <entry of runtime function>
when a method is deoptimized, HotSpot patches the verified_entry (0x20) with a
jump to a stub that handles call-sites that has been made non-entrant. since this jump
is 5 bytes long, it will overwrite ic_miss_call and blow up every caller that
calls this method via the unverified entry (prefix).
the fix is to emit the jump to the runtime function inside the unverfied entry:
prefix:
00: < IC check >
...
0b: je <verified_entry>
11: jeq <entry of runtime function>
16: nop
...
verified_entry:
20: ret
author | Bernhard Urban <bernhard.urban@jku.at> |
---|---|
date | Mon, 30 Sep 2013 09:32:18 +0200 |
parents | c90c698831d7 |
children |
line wrap: on
line source
/* * Copyright (c) 2013, 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 8020215 * @summary Different execution plan when using JIT vs interpreter * @run main Test8020215 */ import java.util.ArrayList; import java.util.List; public class Test8020215 { public static class NamedObject { public int id; public String name; public NamedObject(int id, String name) { this.id = id; this.name = name; } } public static class NamedObjectList { public List<NamedObject> namedObjectList = new ArrayList<NamedObject>(); public NamedObject getBest(int id) { NamedObject bestObject = null; for (NamedObject o : namedObjectList) { bestObject = id==o.id ? getBetter(bestObject, o) : bestObject; } return (bestObject != null) ? bestObject : null; } private static NamedObject getBetter(NamedObject p1, NamedObject p2) { return (p1 == null) ? p2 : (p2 == null) ? p1 : (p2.name.compareTo(p1.name) >= 0) ? p2 : p1; } } static void test(NamedObjectList b, int i) { NamedObject x = b.getBest(2); // test if (x == null) { throw new RuntimeException("x should never be null here! (i=" + i + ")"); } } public static void main(String[] args) { // setup NamedObjectList b = new NamedObjectList(); for (int i = 0; i < 10000; i++) { b.namedObjectList.add(new NamedObject(1, "2012-12-31")); } b.namedObjectList.add(new NamedObject(2, "2013-12-31")); // execution for (int i = 0; i < 12000; i++) { test(b, i); } System.out.println("PASSED"); } }