diff --git a/src/hotspot/share/opto/arraycopynode.cpp b/src/hotspot/share/opto/arraycopynode.cpp index 85b6bd21aece1..c02aefc794379 100644 --- a/src/hotspot/share/opto/arraycopynode.cpp +++ b/src/hotspot/share/opto/arraycopynode.cpp @@ -212,6 +212,15 @@ Node* ArrayCopyNode::try_clone_instance(PhaseGVN *phase, bool can_reshape, int c } } + const TypeInstPtr* dest_type = phase->type(base_dest)->is_instptr(); + if (dest_type->instance_klass() != ik) { + // At parse time, the exact type of the object to clone was not known. That inexact type was captured by the CheckCastPP + // of the newly allocated cloned object (in dest). The exact type is now known (in src), but the type for the cloned object + // (dest) was not updated. When copying the fields below, Store nodes may write to offsets for fields that don't exist in + // the inexact class. The stores would then be assigned an incorrect slice. + return NodeSentinel; + } + assert(ik->nof_nonstatic_fields() <= ArrayCopyLoadStoreMaxElem, "too many fields"); BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); diff --git a/test/hotspot/jtreg/compiler/arraycopy/TestCloneUnknownClassAtParseTime.java b/test/hotspot/jtreg/compiler/arraycopy/TestCloneUnknownClassAtParseTime.java new file mode 100644 index 0000000000000..c05f27b133938 --- /dev/null +++ b/test/hotspot/jtreg/compiler/arraycopy/TestCloneUnknownClassAtParseTime.java @@ -0,0 +1,89 @@ +/* + * Copyright (c) 2025 IBM Corporation. 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 8339526 + * @summary C2: store incorrectly removed for clone() transformed to series of loads/stores + * @run main/othervm -XX:-BackgroundCompilation TestCloneUnknownClassAtParseTime + */ + +public class TestCloneUnknownClassAtParseTime { + private static volatile int volatileField; + static A field; + + public static void main(String[] args) throws CloneNotSupportedException { + A a = new A(); + for (int i = 0; i < 20_000; i++) { + B b = (B)test1(-1); + if (b.field1 != 42 || b.field2 != 42|| b.field3 != 42) { + throw new RuntimeException("Clone wrongly initialized"); + } + inlined1(42); + field = a; + inlined2(); + } + } + + private static A test1(int i) throws CloneNotSupportedException { + int[] nonEscapingArray = new int[1]; + field = new B(42, 42, 42); + + if (i > 0) { + throw new RuntimeException("never taken"); + } + inlined1(i); + + nonEscapingArray[0] = 42; + return inlined2(); + } + + private static A inlined2() throws CloneNotSupportedException { + A a = field; + return (A)a.clone(); + } + + private static void inlined1(int i) { + if (i > 0) { + volatileField = 42; + } + } + + private static class A implements Cloneable { + public Object clone() throws CloneNotSupportedException { + return super.clone(); + } + } + + private static class B extends A { + int field1; + int field2; + int field3; + + B(int v1, int v2, int v3) { + field1 = v1; + field2 = v2; + field3 = v3; + } + } +}