1 /* 2 * Copyright (c) 2002, 2018, 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 * 27 * @summary converted from VM Testbase runtime/jbe/dead/dead15. 28 * VM Testbase keywords: [quick, runtime] 29 * 30 * @library /vmTestbase 31 * /test/lib 32 * @run driver jdk.test.lib.FileInstaller . . 33 * @run main/othervm vm.compiler.jbe.dead.dead15.dead15 34 */ 35 36 package vm.compiler.jbe.dead.dead15; 37 38 // dead15.java 39 40 /* -- Test the elimination of a global variable assignment to itself. 41 Example: 42 43 int bar; 44 void foo() 45 { 46 bar = bar; 47 } 48 49 The assignment to bar can be eliminated. Though assignments of this 50 nature are unlikley to occur in an original code, it can actually 51 happen as a result of other optimizations. For example, consider the 52 following assignments after constant propagation. 53 54 bat = 0; 55 bar = bar + bat; 56 57 After constant propagation, the second statement becomes bar = bar + 0, 58 or bar = bar. This test ensures that the final transformation, (i.e. 59 the elimination of this assignment) will occur. 60 */ 61 62 63 public class dead15 { 64 int i00=0, i01=1, i02=2, i03=3, i04=4; 65 int i05=5, i06=6, i07=7, i08=8, i09=9; 66 int i10=10, i11=11, i12=12, i13=13, i14=14; 67 int i15=15, i16=16, i17=17, i18=18, i19=19; 68 main(String args[])69 public static void main(String args[]) { 70 dead15 dce = new dead15(); 71 72 System.out.println("f()="+dce.f()+"; fopt()="+dce.fopt()); 73 if (dce.f() == dce.fopt()) { 74 System.out.println("Test dead15 Passed."); 75 } else { 76 throw new Error("Test dead15 Failed: f()=" + dce.f() + " != fopt()=" + dce.fopt()); 77 } 78 } 79 80 f()81 int f() { 82 i00 = i00; 83 i01 = i01; 84 i02 = i02; 85 i03 = i03; 86 i04 = i04; 87 i05 = i05; 88 i06 = i06; 89 i07 = i07; 90 i08 = i08; 91 i09 = i09; 92 i10 = i10; 93 i11 = i11; 94 i12 = i12; 95 i13 = i13; 96 i14 = i14; 97 i15 = i15; 98 i16 = i16; 99 i17 = i17; 100 i18 = i18; 101 i19 = i19; 102 103 return i19; 104 } 105 106 // Code fragment after dead code elimination fopt()107 int fopt() { 108 return i19; 109 } 110 } 111