| /* |
| * Copyright (c) 2016, 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. |
| */ |
| package org.graalvm.compiler.core.test; |
| |
| import java.lang.reflect.Field; |
| |
| import org.junit.Assert; |
| import org.junit.Test; |
| |
| import org.graalvm.compiler.nodes.IfNode; |
| import org.graalvm.compiler.nodes.StructuredGraph; |
| import org.graalvm.compiler.phases.common.CanonicalizerPhase; |
| import org.graalvm.compiler.phases.common.IterativeConditionalEliminationPhase; |
| import org.graalvm.compiler.virtual.phases.ea.EarlyReadEliminationPhase; |
| |
| import sun.misc.Unsafe; |
| |
| public class ConditionalEliminationLoadFieldConstantFoldTest extends GraalCompilerTest { |
| public static int intSideEffect; |
| |
| public static final B FinalField = new B(10); |
| |
| private abstract static class A { |
| |
| } |
| |
| private static class B extends A { |
| final int a; |
| |
| B(int a) { |
| this.a = a; |
| } |
| } |
| |
| private static class C extends A { |
| final B b; |
| |
| C(B b) { |
| this.b = b; |
| } |
| } |
| |
| private static class D extends A { |
| final C c; |
| |
| D(C c) { |
| this.c = c; |
| } |
| } |
| |
| private static class E extends D { |
| final Object o; |
| |
| E(C c, Object o) { |
| super(c); |
| this.o = o; |
| } |
| } |
| |
| public static final B CONST_B = new B(10); |
| public static final C CONST_C = new C(CONST_B); |
| public static final D CONST_D = new D(CONST_C); |
| |
| public int testReadConstInBranch(B b) { |
| if (b == CONST_B) { |
| if (b.a == 5) { |
| intSideEffect = b.a; |
| } else { |
| intSideEffect = 10; |
| } |
| } |
| return 0; |
| } |
| |
| public int testMultipleReadsConstInBranch(D d) { |
| if (d == CONST_D) { |
| C c = d.c; |
| B b = c.b; |
| int res = b.a + 12; |
| if (res == 125) { |
| intSideEffect = 12; |
| } |
| } |
| return 0; |
| } |
| |
| public int testLoadFinalInstanceOf(E e) { |
| Object o = e.o; |
| if (o == CONST_C) { |
| if (o instanceof A) { |
| // eliminate, implied by a.x == Const(Subclass) |
| intSideEffect = 1; |
| } else { |
| intSideEffect = 10; |
| } |
| } |
| return 0; |
| } |
| |
| public int testLoadFinalTwiceInstanceOf(E e) { |
| if (e.o == CONST_C) { |
| if (e.o instanceof A) { |
| intSideEffect = 1; |
| } else { |
| intSideEffect = 10; |
| } |
| } |
| return 0; |
| } |
| |
| static class C1 { |
| final int a; |
| |
| C1(int a) { |
| this.a = a; |
| } |
| } |
| |
| static class C2 { |
| final C1 c1; |
| |
| C2(C1 c1) { |
| this.c1 = c1; |
| } |
| } |
| |
| public static int foldThatIsNotAllowed(C2 c2) { |
| // read before, this will be used to load through when folding |
| C1 c1Unknown = c2.c1; |
| |
| // be naughty (will be a store field after canonicalization as it has a constant offset, so |
| // we would be able to eliminate the inner if after an early read elimination but we would |
| // fold before and ce the inner if already) |
| // |
| // note: if the offset would not be constant but a parameter we would not even be able to |
| // remove in inner most if as we cannot rewrite the unsafe store to a store field node as |
| // the store might kill ANY_LOCATION |
| UNSAFE.putObject(c2, C2_C1_OFFSET, C1_AFTER_READ_CONST); |
| |
| if (c2 == C2_CONST) { |
| if (c1Unknown == C1_CONST) { |
| /* |
| * This if can be eliminated (as we rewrite the unsafe store with a constant offset |
| * to a store field node) but the remaining branch must be the false branch. If we |
| * do not fold through both field loads we will canonicalize the unsafe store to a |
| * store field, see the new value and can thus eliminate the true branch |
| * |
| * if we fold through the load fields we would load from the object read before the |
| * store so we miss the unsafe update |
| */ |
| if (c2.c1.a == 10) { |
| intSideEffect = 1; |
| return 1; |
| } else { |
| intSideEffect = 2; |
| return 2; |
| } |
| } else { |
| intSideEffect = -2; |
| return -2; |
| } |
| } else { |
| intSideEffect = -1; |
| return -1; |
| } |
| } |
| |
| public int testLoadFinalTwiceNoReadEliminationInstanceOf(E e) { |
| if (e.o == CONST_C) { |
| /* |
| * we cannot eliminate the second read of e.o although it is a final field. the call to |
| * System.gc (or any other memory checkpoint killing ANY_LOCATION) will prohibit the |
| * elimination of the second load, thus we have two different load nodes, we know that |
| * that first load field is a constant but we do not know for the second one, assuming |
| * e.o is final, as it might have been written in between |
| * |
| * this prohibits us to remove the if (fold through all loads to final fields) and the |
| * instance of e.o |
| */ |
| System.gc(); |
| C c = (C) e.o; |
| if (c.b.a == 10) { |
| intSideEffect = 1; |
| } else { |
| intSideEffect = 10; |
| } |
| } |
| return 0; |
| |
| } |
| |
| private static final C1 C1_CONST = new C1(0); |
| private static final C2 C2_CONST = new C2(C1_CONST); |
| private static final C1 C1_AFTER_READ_CONST = new C1(10); |
| |
| private static Unsafe getUnsafe() { |
| try { |
| return Unsafe.getUnsafe(); |
| } catch (SecurityException e) { |
| } |
| try { |
| Field theUnsafeInstance = Unsafe.class.getDeclaredField("theUnsafe"); |
| theUnsafeInstance.setAccessible(true); |
| return (Unsafe) theUnsafeInstance.get(Unsafe.class); |
| } catch (Exception e) { |
| throw new RuntimeException("exception while trying to get Unsafe.theUnsafe via reflection:", e); |
| } |
| } |
| |
| private static final sun.misc.Unsafe UNSAFE = getUnsafe(); |
| private static final long C2_C1_OFFSET; |
| |
| static { |
| try { |
| Field f = C2.class.getDeclaredField("c1"); |
| C2_C1_OFFSET = UNSAFE.objectFieldOffset(f); |
| } catch (NoSuchFieldException | SecurityException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| @Test |
| public void test01() { |
| checkGraph("testReadConstInBranch", 1); |
| test("testReadConstInBranch", new B(1)); |
| } |
| |
| @Test |
| public void test02() { |
| checkGraph("testMultipleReadsConstInBranch", 1); |
| } |
| |
| @Test |
| public void test03() { |
| checkGraph("testLoadFinalInstanceOf", 1); |
| } |
| |
| @Test |
| public void test04() { |
| checkGraph("testLoadFinalTwiceInstanceOf", 1); |
| } |
| |
| @Test |
| public void test05() { |
| checkGraph("testLoadFinalTwiceNoReadEliminationInstanceOf", 2); |
| } |
| |
| @Test(expected = AssertionError.class) |
| @SuppressWarnings("try") |
| public void test06() { |
| Result actual = executeActual(getResolvedJavaMethod("foldThatIsNotAllowed"), null, C2_CONST); |
| UNSAFE.putObject(C2_CONST, C2_C1_OFFSET, C1_CONST); |
| Result expected = executeExpected(getResolvedJavaMethod("foldThatIsNotAllowed"), null, C2_CONST); |
| Assert.assertEquals(expected.returnValue, actual.returnValue); |
| } |
| |
| @SuppressWarnings("try") |
| private StructuredGraph checkGraph(String name, int nrOfIfsAfter) { |
| StructuredGraph g = parseForCompile(getResolvedJavaMethod(name)); |
| CanonicalizerPhase c = new CanonicalizerPhase(); |
| c.apply(g, getDefaultHighTierContext()); |
| new EarlyReadEliminationPhase(c).apply(g, getDefaultHighTierContext()); |
| new IterativeConditionalEliminationPhase(c, false).apply(g, getDefaultHighTierContext()); |
| Assert.assertEquals("Nr of Ifs left does not match", nrOfIfsAfter, g.getNodes().filter(IfNode.class).count()); |
| c.apply(g, getDefaultHighTierContext()); |
| return g; |
| } |
| |
| } |