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/hoist/hoist03. 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.hoist.hoist03.hoist03 34 */ 35 36 package vm.compiler.jbe.hoist.hoist03; 37 38 39 // hoist03.java 40 41 /* -- Loop invariant if-then code where the "then" branch is always executed. 42 Example: 43 44 double foo_static[5000]; 45 for(i=0 ; i<100 ; i++) { 46 if (i < 0) { 47 foo_static[k] = -1.; 48 } 49 else { 50 foo_static[k] = +1.; 51 } 52 } 53 54 Can the optimizer break the code up to avoid re-checking the conditional assignment within the loop when it is known that i will never be < 0 during that loop. 55 56 */ 57 58 public class hoist03 { 59 int LEN = 60000; 60 int a[] = new int[LEN]; 61 int aopt[] = new int[LEN]; 62 63 public static void main(String args[]) { 64 hoist03 hst = new hoist03(); 65 66 hst.f(); 67 hst.fopt(); 68 if (hst.eCheck()) { 69 System.out.println("Test hoist03 Passed."); 70 } else { 71 throw new Error("Test hoist03 Failed."); 72 } 73 } 74 75 void f() { 76 // i is always > 0, hence the conditional statement i < 0 is loop invariant. 77 int k = 0; 78 79 for (int j = 0; j < 200; j++) { 80 for (int i = 0; i < 300; i++) { 81 if (i < 0) { 82 a[k++] = -1; 83 } 84 else { 85 a[k++] = 1; 86 } 87 } 88 } 89 } 90 91 92 // Code fragment after the invariant expression is hoisted out of the loop. 93 void fopt() { 94 int k = 0; 95 96 for (int j = 0; j < 200; j++) { 97 for (int i = 0; i < 300; i++) { 98 aopt[k++] = 1; 99 } 100 } 101 } 102 103 104 // Check Loop Hoisting results 105 boolean eCheck() { 106 for (int i = 0; i < a.length; i++) 107 if (a[i] != aopt[i]) { 108 System.out.println("a["+i+"]="+a[i]+"; aopt["+i+"]="+aopt[i]); 109 return false; 110 } 111 112 return true; 113 } 114 }