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authorGravatar Roland Westrelin <roland@openjdk.org> 2021-04-16 11:34:45 +0000
committerGravatar Roland Westrelin <roland@openjdk.org> 2021-04-16 11:34:45 +0000
commit7137328006739e839e8bed8826f286883ebf3d00 (patch)
treed64648ed6774280dd324492009089277ab7d55d4
parent1d66a155c711906fbb5e8e976fd6585ef491ea68 (diff)
downloadjdk-7137328006739e839e8bed8826f286883ebf3d00.tar.gz
jdk-7137328006739e839e8bed8826f286883ebf3d00.zip
8264958: C2 compilation fails with assert "n is later than its clone"
Reviewed-by: neliasso, thartmann
-rw-r--r--src/hotspot/share/opto/loopopts.cpp2
-rw-r--r--test/hotspot/jtreg/compiler/loopstripmining/OuterStripMinedLoopLoadWronglyHoisted.java57
2 files changed, 58 insertions, 1 deletions
diff --git a/src/hotspot/share/opto/loopopts.cpp b/src/hotspot/share/opto/loopopts.cpp
index 093bd7f414e..dd26096bbf8 100644
--- a/src/hotspot/share/opto/loopopts.cpp
+++ b/src/hotspot/share/opto/loopopts.cpp
@@ -1479,7 +1479,7 @@ void PhaseIdealLoop::split_if_with_blocks_post(Node *n) {
IdealLoopTree* x_loop = get_loop(x_ctrl);
Node* x_head = x_loop->_head;
if (x_head->is_Loop() && (x_head->is_OuterStripMinedLoop() || x_head->as_Loop()->is_strip_mined())) {
- if (is_dominator(n_ctrl, x_head)) {
+ if (is_dominator(n_ctrl, x_head) && n_ctrl != x_head) {
// Anti dependence analysis is sometimes too
// conservative: a store in the outer strip mined loop
// can prevent a load from floating out of the outer
diff --git a/test/hotspot/jtreg/compiler/loopstripmining/OuterStripMinedLoopLoadWronglyHoisted.java b/test/hotspot/jtreg/compiler/loopstripmining/OuterStripMinedLoopLoadWronglyHoisted.java
new file mode 100644
index 00000000000..53e24fe7b7b
--- /dev/null
+++ b/test/hotspot/jtreg/compiler/loopstripmining/OuterStripMinedLoopLoadWronglyHoisted.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2021, Red Hat, Inc. 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 8264958
+ * @summary C2 compilation fails with assert "n is later than its clone"
+ *
+ * @run main/othervm -Xbatch OuterStripMinedLoopLoadWronglyHoisted
+ *
+ */
+
+
+public class OuterStripMinedLoopLoadWronglyHoisted {
+ int a;
+ int b;
+ short c;
+
+ void test() {
+ for (int i = 0; i < 10; ++i) {
+ a = c;
+ if (i > 1) {
+ b = 0;
+ }
+ c = (short)(b - 7);
+ }
+ a--;
+ }
+
+ public static void main(String[] args) {
+ OuterStripMinedLoopLoadWronglyHoisted t = new OuterStripMinedLoopLoadWronglyHoisted();
+ for (int i = 0; i < 100_000; ++i) {
+ t.test();
+ }
+ }
+}
+