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1   /*
2    * Copyright (c) 1994, 2003, 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 sun.tools.tree;
27  
28  import sun.tools.java.*;
29  import sun.tools.asm.Assembler;
30  import sun.tools.asm.Label;
31  
32  /**
33   * WARNING: The contents of this source file are not part of any
34   * supported API.  Code that depends on them does so at its own risk:
35   * they are subject to change or removal without notice.
36   */
37  public
38  class NotEqualExpression extends BinaryEqualityExpression {
39      /**
40       * constructor
41       */
42      public NotEqualExpression(long where, Expression left, Expression right) {
43          super(NE, where, left, right);
44      }
45  
46      /**
47       * Evaluate
48       */
49      Expression eval(int a, int b) {
50          return new BooleanExpression(where, a != b);
51      }
52      Expression eval(long a, long b) {
53          return new BooleanExpression(where, a != b);
54      }
55      Expression eval(float a, float b) {
56          return new BooleanExpression(where, a != b);
57      }
58      Expression eval(double a, double b) {
59          return new BooleanExpression(where, a != b);
60      }
61      Expression eval(boolean a, boolean b) {
62          return new BooleanExpression(where, a != b);
63      }
64  
65      /**
66       * Simplify
67       */
68      Expression simplify() {
69          if (left.isConstant() && !right.isConstant()) {
70              return new NotEqualExpression(where, right, left);
71          }
72          return this;
73      }
74  
75      /**
76       * Code
77       */
78      void codeBranch(Environment env, Context ctx, Assembler asm, Label lbl, boolean whenTrue) {
79          left.codeValue(env, ctx, asm);
80          switch (left.type.getTypeCode()) {
81            case TC_BOOLEAN:
82            case TC_INT:
83              if (!right.equals(0)) {
84                  right.codeValue(env, ctx, asm);
85                  asm.add(where, whenTrue ? opc_if_icmpne : opc_if_icmpeq, lbl, whenTrue);
86                  return;
87              }
88              break;
89            case TC_LONG:
90              right.codeValue(env, ctx, asm);
91              asm.add(where, opc_lcmp);
92              break;
93            case TC_FLOAT:
94              right.codeValue(env, ctx, asm);
95              asm.add(where, opc_fcmpl);
96              break;
97            case TC_DOUBLE:
98              right.codeValue(env, ctx, asm);
99              asm.add(where, opc_dcmpl);
100             break;
101           case TC_ARRAY:
102           case TC_CLASS:
103           case TC_NULL:
104             if (right.equals(0)) {
105                 asm.add(where, whenTrue ? opc_ifnonnull : opc_ifnull, lbl, whenTrue);
106             } else {
107                 right.codeValue(env, ctx, asm);
108                 asm.add(where, whenTrue ? opc_if_acmpne : opc_if_acmpeq, lbl, whenTrue);
109             }
110             return;
111           default:
112             throw new CompilerError("Unexpected Type");
113         }
114         asm.add(where, whenTrue ? opc_ifne : opc_ifeq, lbl, whenTrue);
115     }
116 }