1 /* 2 * Copyright (c) 2024, 2025, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.incubator.code.analysis; 27 28 import jdk.incubator.code.*; 29 30 /** 31 * Functionality to transform a code model into pure SSA form, replacing operations that declare variables and 32 * access them with the use of values they depend on or additional block parameters. 33 */ 34 public final class SSA { 35 private SSA() { 36 } 37 38 /** 39 * Applies an SSA transformation to an operation with bodies, replacing operations that declare variables and 40 * access them with the use of values they depend on or additional block parameters. 41 * <p> 42 * The operation should first be in lowered form before applying this transformation. 43 * <p> 44 * Note: this implementation does not currently work correctly when a variable is stored to within an exception 45 * region and read from outside as a result of catching an exception. In such cases a complete transformation may be 46 * not possible and such variables will need to be retained. 47 * 48 * @param nestedOp the operation with bodies 49 * @return the transformed operation 50 * @param <T> the operation type 51 */ 52 public static <T extends Op & Op.Nested> T transform(T nestedOp) { 53 // @@@ property is used to test both impls 54 if (!"cytron".equalsIgnoreCase(System.getProperty("babylon.ssa"))) { 55 return SSABraun.transform(nestedOp); 56 } else { 57 return SSACytron.transform(nestedOp); 58 } 59 } 60 }