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src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.java/src/org/graalvm/compiler/java/JsrScope.java

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rev 56282 : [mq]: graal
   1 /*
   2  * Copyright (c) 2011, 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 package org.graalvm.compiler.java;
  26 
  27 public class JsrScope {
  28 








  29     public static final JsrScope EMPTY_SCOPE = new JsrScope();
  30 
  31     private final long scope;


  32 
  33     private JsrScope(long scope) {
  34         this.scope = scope;

  35     }
  36 
  37     public JsrScope() {
  38         this.scope = 0;

  39     }
  40 
  41     public int nextReturnAddress() {
  42         return (int) (scope & 0xffff);
  43     }
  44 
  45     public JsrScope push(int jsrReturnBci) {
  46         if ((scope & 0xffff000000000000L) != 0) {
  47             throw new JsrNotSupportedBailout("only four jsr nesting levels are supported");






  48         }
  49         return new JsrScope((scope << 16) | jsrReturnBci);



  50     }
  51 



  52     public boolean isEmpty() {
  53         return scope == 0;
  54     }
  55 





















  56     public boolean isPrefixOf(JsrScope other) {
  57         return (scope & other.scope) == scope;





  58     }
  59 





  60     public JsrScope pop() {
  61         return new JsrScope(scope >>> 16);



  62     }
  63 
  64     @Override
  65     public int hashCode() {
  66         return (int) (scope ^ (scope >>> 32));






  67     }
  68 
  69     @Override
  70     public boolean equals(Object obj) {
  71         if (this == obj) {
  72             return true;
  73         }
  74         return obj != null && getClass() == obj.getClass() && scope == ((JsrScope) obj).scope;

















  75     }
  76 
  77     @Override
  78     public String toString() {
  79         StringBuilder sb = new StringBuilder();
  80         long tmp = scope;
  81         sb.append(" [");
  82         while (tmp != 0) {
  83             sb.append(", ").append(tmp & 0xffff);
  84             tmp = tmp >>> 16;



  85         }
  86         sb.append(']');
  87         return sb.toString();
  88     }
  89 }
   1 /*
   2  * Copyright (c) 2011, 2019, 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 package org.graalvm.compiler.java;
  26 
  27 import org.graalvm.compiler.bytecode.Bytecodes;
  28 
  29 /**
  30  * Represents a subroutine entered via {@link Bytecodes#JSR} and exited via {@link Bytecodes#RET}.
  31  */
  32 public final class JsrScope {
  33 
  34     /**
  35      * The scope outside of any JSR/RET subroutine.
  36      */
  37     public static final JsrScope EMPTY_SCOPE = new JsrScope();
  38 
  39     private final char returnAddress;
  40 
  41     private final JsrScope parent;
  42 
  43     private JsrScope(int returnBci, JsrScope parent) {
  44         this.returnAddress = (char) returnBci;
  45         this.parent = parent;
  46     }
  47 
  48     private JsrScope() {
  49         this.returnAddress = 0;
  50         this.parent = null;
  51     }
  52 
  53     public int nextReturnAddress() {
  54         return returnAddress;
  55     }
  56 
  57     /**
  58      * Enters a new subroutine from the current scope represented by this object.
  59      *
  60      * @param returnBci the bytecode address returned to when leaving the new scope
  61      * @return an object representing the newly entered scope
  62      */
  63     public JsrScope push(int returnBci) {
  64         if (returnBci == 0) {
  65             throw new IllegalArgumentException("A bytecode subroutine cannot have a return address of 0");
  66         }
  67         if (returnBci < 1 || returnBci > 0xFFFF) {
  68             throw new IllegalArgumentException("Bytecode subroutine return address cannot be encoded as a char: " + returnBci);
  69         }
  70         return new JsrScope(returnBci, this);
  71     }
  72 
  73     /**
  74      * Determines if this is the scope outside of any JSR/RET subroutine.
  75      */
  76     public boolean isEmpty() {
  77         return returnAddress == 0;
  78     }
  79 
  80     /**
  81      * Gets the ancestry of this scope starting with the {@link #returnAddress} of this scope's most
  82      * distant ancestor and ending with the {@link #returnAddress} of this object.
  83      *
  84      * @return a String where each character is a 16-bit BCI. This value can be converted to an
  85      *         {@code int[]} with {@code value.chars().toArray()}.
  86      */
  87     public String getAncestry() {
  88         StringBuilder sb = new StringBuilder();
  89         for (JsrScope s = this; s != null; s = s.parent) {
  90             if (!s.isEmpty()) {
  91                 sb.append(s.returnAddress);
  92             }
  93         }
  94         return sb.reverse().toString();
  95     }
  96 
  97     /**
  98      * Determines if the {@linkplain #getAncestry() ancestry} of this scope is a prefix of the
  99      * ancestry of {@code other}.
 100      */
 101     public boolean isPrefixOf(JsrScope other) {
 102         if (isEmpty()) {
 103             return true;
 104         }
 105         String ancestry = getAncestry();
 106         String otherAncestry = other.getAncestry();
 107         return otherAncestry.startsWith(ancestry);
 108     }
 109 
 110     /**
 111      * Gets this scope's parent.
 112      *
 113      * @return this scope's parent or {@link #EMPTY_SCOPE} if this is the {@link #EMPTY_SCOPE}
 114      */
 115     public JsrScope pop() {
 116         if (isEmpty()) {
 117             return this;
 118         }
 119         return parent;
 120     }
 121 
 122     @Override
 123     public int hashCode() {
 124         int hc = returnAddress;
 125         JsrScope ancestor = parent;
 126         while (ancestor != null) {
 127             hc = hc ^ ancestor.returnAddress;
 128             ancestor = ancestor.parent;
 129         }
 130         return hc;
 131     }
 132 
 133     @Override
 134     public boolean equals(Object obj) {
 135         if (this == obj) {
 136             return true;
 137         }
 138         if (obj != null && getClass() == obj.getClass()) {
 139             JsrScope ancestor = this;
 140             JsrScope otherAncestor = (JsrScope) obj;
 141             while (ancestor != null) {
 142                 if (otherAncestor == null) {
 143                     return false;
 144                 }
 145                 if (otherAncestor.returnAddress != ancestor.returnAddress) {
 146                     return false;
 147                 }
 148                 ancestor = ancestor.parent;
 149                 otherAncestor = otherAncestor.parent;
 150             }
 151             if (otherAncestor == null) {
 152                 return true;
 153             }
 154         }
 155         return false;
 156     }
 157 
 158     @Override
 159     public String toString() {
 160         StringBuilder sb = new StringBuilder();
 161 
 162         for (JsrScope ancestor = this; ancestor != null; ancestor = ancestor.parent) {
 163             if (!ancestor.isEmpty()) {
 164                 if (sb.length() != 0) {
 165                     sb.append(", ");
 166                 }
 167                 sb.append((int) ancestor.returnAddress);
 168             }
 169         }
 170         return "[" + sb + "]";

 171     }
 172 }
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