1 /*
   2  * Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 8030976 8059226
  27  * @library /test/lib /
  28  * @modules java.base/jdk.internal.org.objectweb.asm
  29  *          java.base/jdk.internal.misc
  30  *          java.compiler
  31  *          java.management
  32  *          jdk.internal.jvmstat/sun.jvmstat.monitor
  33  *
  34  * @build sun.hotspot.WhiteBox
  35  * @run driver ClassFileInstaller sun.hotspot.WhiteBox
  36  *                                sun.hotspot.WhiteBox$WhiteBoxPermission
  37  * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
  38  *                   -XX:+WhiteBoxAPI -XX:+LogCompilation
  39  *                   -XX:CompileCommand=compileonly,UnstableIfExecutable.test
  40  *                   -XX:LogFile=always_taken_not_fired.xml
  41  *                   compiler.uncommontrap.TestUnstableIfTrap ALWAYS_TAKEN false
  42  * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
  43  *                   -XX:+WhiteBoxAPI -XX:+LogCompilation
  44  *                   -XX:CompileCommand=compileonly,UnstableIfExecutable.test
  45  *                   -XX:LogFile=always_taken_fired.xml
  46  *                   compiler.uncommontrap.TestUnstableIfTrap ALWAYS_TAKEN true
  47  * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
  48  *                   -XX:+WhiteBoxAPI -XX:+LogCompilation
  49  *                   -XX:CompileCommand=compileonly,UnstableIfExecutable.test
  50  *                   -XX:LogFile=never_taken_not_fired.xml
  51  *                   compiler.uncommontrap.TestUnstableIfTrap NEVER_TAKEN false
  52  * @run main/othervm -Xbatch -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
  53  *                   -XX:+WhiteBoxAPI -XX:+LogCompilation
  54  *                   -XX:CompileCommand=compileonly,UnstableIfExecutable.test
  55  *                   -XX:LogFile=never_taken_fired.xml
  56  *                   compiler.uncommontrap.TestUnstableIfTrap NEVER_TAKEN true
  57  * @run driver compiler.testlibrary.uncommontrap.Verifier always_taken_not_fired.xml
  58  *                                                        always_taken_fired.xml
  59  *                                                        never_taken_not_fired.xml
  60  *                                                        never_taken_fired.xml
  61  */
  62 
  63 package compiler.uncommontrap;
  64 
  65 import compiler.testlibrary.uncommontrap.Verifier;
  66 import jdk.internal.org.objectweb.asm.ClassVisitor;
  67 import jdk.internal.org.objectweb.asm.ClassWriter;
  68 import jdk.internal.org.objectweb.asm.Label;
  69 import jdk.internal.org.objectweb.asm.MethodVisitor;
  70 import jdk.test.lib.ByteCodeLoader;
  71 import jdk.test.lib.Platform;
  72 import sun.hotspot.WhiteBox;
  73 
  74 import java.io.File;
  75 import java.io.FileWriter;
  76 import java.io.IOException;
  77 import java.lang.reflect.Method;
  78 import java.util.Properties;
  79 
  80 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_ABSTRACT;
  81 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PUBLIC;
  82 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_STATIC;
  83 import static jdk.internal.org.objectweb.asm.Opcodes.ACC_VOLATILE;
  84 import static jdk.internal.org.objectweb.asm.Opcodes.GETSTATIC;
  85 import static jdk.internal.org.objectweb.asm.Opcodes.GOTO;
  86 import static jdk.internal.org.objectweb.asm.Opcodes.IADD;
  87 import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_1;
  88 import static jdk.internal.org.objectweb.asm.Opcodes.IFEQ;
  89 import static jdk.internal.org.objectweb.asm.Opcodes.ILOAD;
  90 import static jdk.internal.org.objectweb.asm.Opcodes.ISUB;
  91 import static jdk.internal.org.objectweb.asm.Opcodes.RETURN;
  92 
  93 public class TestUnstableIfTrap {
  94     private static final WhiteBox WB = WhiteBox.getWhiteBox();
  95     private static final String CLASS_NAME = "UnstableIfExecutable";
  96     private static final String METHOD_NAME = "test";
  97     private static final String FIELD_NAME = "field";
  98     private static final int ITERATIONS = 1_000_000;
  99     // There is no dependency on particular class file version, so it could be
 100     // set to any version (if you're updating this test for Java 42).
 101     private static final int CLASS_FILE_VERSION = 49;
 102     private static final int MAX_TIER = 4;
 103     // This test aimed to verify that uncommon trap with reason "unstable_if"
 104     // is emitted when method that contain control-flow divergence such that
 105     // one of two branches is never taken (and other one is taken always).
 106     // C2 will made a decision whether or not the branch was ever taken
 107     // depending on method's profile.
 108     // If profile was collected for a few method's invocations, then C2 will not
 109     // trust in branches' probabilities and the tested trap won't be emitted.
 110     // In fact, a method has to be invoked at least 40 time at the day when this
 111     // comment was written (see Parse::dynamic_branch_prediction for an actual
 112     // value). It would be to implementation dependent to use "40" as
 113     // a threshold value in the test, so in order to improve test's robustness
 114     // the threshold value is 1000: if the tested method was compiled by C2
 115     // before it was invoked 1000 times, then we won't verify that trap was
 116     // emitted and fired.
 117     private static final int MIN_INVOCATIONS_BEFORE_C2_COMPILATION = 1000;
 118     /**
 119      * Description of test case parameters and uncommon trap that will
 120      * be emitted during tested method compilation.
 121      */
 122     private static enum TestCaseName {
 123         ALWAYS_TAKEN(false, "taken always"),
 124         NEVER_TAKEN(true, "taken never");
 125         TestCaseName(boolean predicate, String comment) {
 126             this.predicate = predicate;
 127             this.comment = comment;
 128         }
 129 
 130         public final boolean predicate;
 131         public final String name = "unstable_if";
 132         public final String comment;
 133     }
 134 
 135     public static void main(String args[]) {
 136         if (args.length != 2) {
 137             throw new Error("Expected two arguments: test case name and a "
 138                     + "boolean determining if uncommon trap should be fired.");
 139         }
 140         test(TestCaseName.valueOf(args[0]), Boolean.valueOf(args[1]));
 141     }
 142 
 143     private static void test(TestCaseName testCase, boolean shouldBeFired) {
 144         Method testMethod;
 145         Label unstableIfLocation = new Label();
 146         boolean shouldBeEmitted;
 147         boolean compiledToEarly = false;
 148 
 149         try {
 150             Class testClass = ByteCodeLoader.load(CLASS_NAME,
 151                     generateTest(unstableIfLocation));
 152             testMethod = testClass.getDeclaredMethod(METHOD_NAME,
 153                     boolean.class);
 154             for (int i = 0; i < ITERATIONS; i++) {
 155                 testMethod.invoke(null, testCase.predicate);
 156                 if (i < MIN_INVOCATIONS_BEFORE_C2_COMPILATION
 157                         && isMethodCompiledByC2(testMethod)) {
 158                     compiledToEarly = true;
 159                     // There is no sense in further invocations: we already
 160                     // decided to avoid verification.
 161                     break;
 162                 }
 163             }
 164             // We're checking that trap should be emitted (i.e. it was compiled
 165             // by C2) before the trap is fired, because otherwise the nmethod
 166             // will be deoptimized and isMethodCompiledByC2 will return false.
 167             shouldBeEmitted = isMethodCompiledByC2(testMethod)
 168                     && !compiledToEarly;
 169             if (shouldBeFired) {
 170                 testMethod.invoke(null, !testCase.predicate);
 171             }
 172         } catch (ReflectiveOperationException e) {
 173             throw new Error("Test case should be generated, loaded and executed"
 174                     + " without any issues.", e);
 175         }
 176 
 177         shouldBeFired &= shouldBeEmitted;
 178 
 179         Properties properties = new Properties();
 180         properties.setProperty(Verifier.VERIFICATION_SHOULD_BE_SKIPPED,
 181                 Boolean.toString(compiledToEarly));
 182         properties.setProperty(Verifier.UNCOMMON_TRAP_SHOULD_EMITTED,
 183                 Boolean.toString(shouldBeEmitted));
 184         properties.setProperty(Verifier.UNCOMMON_TRAP_SHOULD_FIRED,
 185                 Boolean.toString(shouldBeFired));
 186         properties.setProperty(Verifier.UNCOMMON_TRAP_NAME, testCase.name);
 187         properties.setProperty(Verifier.UNCOMMON_TRAP_COMMENT,
 188                 testCase.comment);
 189         properties.setProperty(Verifier.UNCOMMON_TRAP_BCI,
 190                 Integer.toString(unstableIfLocation.getOffset()));
 191 
 192         properties.list(System.out);
 193 
 194         File f = new File(WB.getStringVMFlag("LogFile") +
 195                 Verifier.PROPERTIES_FILE_SUFFIX);
 196         try (FileWriter wr = new FileWriter(f)) {
 197             properties.store(wr, "");
 198         } catch (IOException e) {
 199             throw new Error("Unable to store test properties.", e);
 200         }
 201     }
 202 
 203     private static boolean isMethodCompiledByC2(Method m) {
 204         boolean isTiered = WB.getBooleanVMFlag("TieredCompilation");
 205         boolean isMethodCompiled = WB.isMethodCompiled(m);
 206         boolean isMethodCompiledAtMaxTier
 207                 = WB.getMethodCompilationLevel(m) == MAX_TIER;
 208 
 209         return Platform.isServer() && !Platform.isEmulatedClient() && isMethodCompiled
 210                 && (!isTiered || isMethodCompiledAtMaxTier);
 211     }
 212 
 213     /**
 214      * Generates class with name {@code CLASS_NAME}, which will contain a
 215      * static method {@code METHOD_NAME}:
 216      *
 217      * <pre>{@code
 218      * public abstract class UnstableIfExecutable {
 219      *   private static int field = 0;
 220      *
 221      *   public static void test(boolean alwaysTrue) {
 222      *     if (alwaysTrue) {
 223      *       field++;
 224      *     } else {
 225      *       field--;
 226      *     }
 227      *   }
 228      * }
 229      * }</pre>
 230      *
 231      * @return generated bytecode.
 232      */
 233     private static byte[] generateTest(Label unstableIfLocation) {
 234         ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
 235 
 236         cw.visit(CLASS_FILE_VERSION, ACC_PUBLIC | ACC_ABSTRACT, CLASS_NAME,
 237                 null, "java/lang/Object", null);
 238 
 239         cw.visitField(ACC_PUBLIC | ACC_STATIC | ACC_VOLATILE, FIELD_NAME,
 240                 "I", null, Integer.valueOf(0));
 241 
 242         generateTestMethod(cw, unstableIfLocation);
 243 
 244         return cw.toByteArray();
 245     }
 246 
 247     private static void generateTestMethod(ClassVisitor cv,
 248             Label unstableIfLocation) {
 249         MethodVisitor mv = cv.visitMethod(ACC_PUBLIC | ACC_STATIC, METHOD_NAME,
 250                 "(Z)V", null, null);
 251         mv.visitCode();
 252 
 253         Label end = new Label();
 254         Label falseBranch = new Label();
 255 
 256         // push "field" field's value and 1 to stack
 257         mv.visitFieldInsn(GETSTATIC, CLASS_NAME, FIELD_NAME, "I");
 258         mv.visitInsn(ICONST_1);
 259         // load argument's value
 260         mv.visitVarInsn(ILOAD, 0); // alwaysTrue
 261         // here is our unstable if
 262         mv.visitLabel(unstableIfLocation);
 263         mv.visitJumpInsn(IFEQ, falseBranch);
 264         // increment on "true"
 265         mv.visitInsn(IADD);
 266         mv.visitJumpInsn(GOTO, end);
 267         // decrement on "false"
 268         mv.visitLabel(falseBranch);
 269         mv.visitInsn(ISUB);
 270         mv.visitLabel(end);
 271         // bye bye
 272         mv.visitInsn(RETURN);
 273 
 274         mv.visitMaxs(0, 0);
 275         mv.visitEnd();
 276     }
 277 }
 278