--- old/src/share/vm/c1/c1_ValueMap.hpp 2017-02-28 16:34:20.736778014 +0100 +++ new/src/share/vm/c1/c1_ValueMap.hpp 2017-02-28 16:34:20.668778227 +0100 @@ -157,6 +157,12 @@ void do_UnsafePutRaw (UnsafePutRaw* x) { kill_memory(); } void do_UnsafePutObject(UnsafePutObject* x) { kill_memory(); } void do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x) { kill_memory(); } + void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ } + void do_UnsafeGetObject(UnsafeGetObject* x) { + if (x->is_volatile()) { // the JMM requires this + kill_memory(); + } + } void do_Intrinsic (Intrinsic* x) { if (!x->preserves_state()) kill_memory(); } void do_Phi (Phi* x) { /* nothing to do */ } @@ -197,8 +203,6 @@ void do_OsrEntry (OsrEntry* x) { /* nothing to do */ } void do_ExceptionObject(ExceptionObject* x) { /* nothing to do */ } void do_RoundFP (RoundFP* x) { /* nothing to do */ } - void do_UnsafeGetRaw (UnsafeGetRaw* x) { /* nothing to do */ } - void do_UnsafeGetObject(UnsafeGetObject* x) { /* nothing to do */ } void do_ProfileCall (ProfileCall* x) { /* nothing to do */ } void do_ProfileReturnType (ProfileReturnType* x) { /* nothing to do */ } void do_ProfileInvoke (ProfileInvoke* x) { /* nothing to do */ }; --- /dev/null 2017-02-26 20:56:26.359175879 +0100 +++ new/test/compiler/c1/UnsafeVolatileGuardTest.java 2017-02-28 16:34:20.892777526 +0100 @@ -0,0 +1,81 @@ +/* + * Copyright (c) 2017, 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. + */ + +import java.lang.reflect.Field; + +/** + * @test + * @bug 8175887 + * @summary C1 value numbering handling of Unsafe.get*Volatile is incorrect + * @modules java.base/jdk.internal.misc:+open + * @run main/othervm -XX:TieredStopAtLevel=1 UnsafeVolatileGuardTest + */ +public class UnsafeVolatileGuardTest { + volatile static private int a; + static private int b; + + static final jdk.internal.misc.Unsafe UNSAFE; + + static final Object BASE; + static final long OFFSET; + + static { + try { + Field f = jdk.internal.misc.Unsafe.class.getDeclaredField("theUnsafe"); + f.setAccessible(true); + UNSAFE = (jdk.internal.misc.Unsafe) f.get(null); + } catch (Exception e) { + throw new RuntimeException("Unable to get Unsafe instance.", e); + } + + try { + Field f = UnsafeVolatileGuardTest.class.getDeclaredField("a"); + BASE = UNSAFE.staticFieldBase(f); + OFFSET = UNSAFE.staticFieldOffset(f); + } catch (Exception e) { + throw new RuntimeException(e); + } + } + + public static void main(String [] args) throws Exception { + for (int i = 0; i < 100; i++) { + new Thread() { + + @Override + public void run() { + int tt = b; // makes the JVM CSE the value of b + + while (UNSAFE.getIntVolatile(BASE, OFFSET) == 0) {} // burn + if (b == 0) { + System.out.println("error"); + System.exit(1); // fail hard + } + } + + }.start(); + } + + b = 1; + a = 1; + } +} --- /dev/null 2017-02-26 20:56:26.359175879 +0100 +++ new/test/compiler/c1/VolatileGuardTest.java 2017-02-28 16:34:21.100776876 +0100 @@ -0,0 +1,56 @@ +/* + * Copyright (c) 2017, 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 7170145 + * @summary C1 doesn't respect the JMM with volatile field loads + * + * @run main/othervm -XX:TieredStopAtLevel=1 VolatileGuardTest + */ +public class VolatileGuardTest { + volatile static private int a; + static private int b; + + public static void main(String [] args) throws Exception { + for (int i = 0; i < 100; i++) { + new Thread() { + + @Override + public void run() { + int tt = b; // makes the JVM CSE the value of b + + while (a == 0) {} // burn + if (b == 0) { + System.out.println("error"); + System.exit(1); // fail hard + } + } + + }.start(); + } + + b = 1; + a = 1; + } +}