8023472: C2 optimization breaks with G1
Summary: set control edge for previous value load in G1 pre-barrier
Reviewed-by: twisti
--- a/hotspot/src/share/vm/opto/graphKit.cpp Fri Aug 23 11:41:37 2013 -0700
+++ b/hotspot/src/share/vm/opto/graphKit.cpp Fri Aug 23 18:04:35 2013 -0700
@@ -3595,7 +3595,7 @@
if (do_load) {
// load original value
// alias_idx correct??
- pre_val = __ load(no_ctrl, adr, val_type, bt, alias_idx);
+ pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
}
// if (pre_val != NULL)
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/gcbarriers/G1CrashTest.java Fri Aug 23 18:04:35 2013 -0700
@@ -0,0 +1,84 @@
+/*
+ * 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 8023472
+ * @summary C2 optimization breaks with G1
+ *
+ * @run main/othervm -Xbatch -XX:+IgnoreUnrecognizedVMOptions -XX:-TieredCompilation -Dcount=100000 G1CrashTest
+ *
+ * @author pbiswal@palantir.com
+ */
+
+public class G1CrashTest {
+ static Object[] set = new Object[11];
+
+ public static void main(String[] args) throws InterruptedException {
+ for (int j = 0; j < Integer.getInteger("count"); j++) {
+ Object key = new Object();
+ insertKey(key);
+ if (j > set.length / 2) {
+ Object[] oldKeys = set;
+ set = new Object[2 * set.length - 1];
+ for (Object o : oldKeys) {
+ if (o != null)
+ insertKey(o);
+ }
+ }
+ }
+ }
+
+ static void insertKey(Object key) {
+ int hash = key.hashCode() & 0x7fffffff;
+ int index = hash % set.length;
+ Object cur = set[index];
+ if (cur == null)
+ set[index] = key;
+ else
+ insertKeyRehash(key, index, hash, cur);
+ }
+
+ static void insertKeyRehash(Object key, int index, int hash, Object cur) {
+ int loopIndex = index;
+ int firstRemoved = -1;
+ do {
+ if (cur == "dead")
+ firstRemoved = 1;
+ index--;
+ if (index < 0)
+ index += set.length;
+ cur = set[index];
+ if (cur == null) {
+ if (firstRemoved != -1)
+ set[firstRemoved] = "dead";
+ else
+ set[index] = key;
+ return;
+ }
+ } while (index != loopIndex);
+ if (firstRemoved != -1)
+ set[firstRemoved] = null;
+ }
+}