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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.Label;
30  import sun.tools.asm.Assembler;
31  import java.io.PrintStream;
32  import java.util.Hashtable;
33  
34  /**
35   * WARNING: The contents of this source file are not part of any
36   * supported API.  Code that depends on them does so at its own risk:
37   * they are subject to change or removal without notice.
38   */
39  public
40  class BinaryExpression extends UnaryExpression {
41      Expression left;
42  
43      /**
44       * Constructor
45       */
46      BinaryExpression(int op, long where, Type type, Expression left, Expression right) {
47          super(op, where, type, right);
48          this.left = left;
49      }
50  
51      /**
52       * Order the expression based on precedence
53       */
54      public Expression order() {
55          if (precedence() > left.precedence()) {
56              UnaryExpression e = (UnaryExpression)left;
57              left = e.right;
58              e.right = order();
59              return e;
60          }
61          return this;
62      }
63  
64      /**
65       * Check a binary expression
66       */
67      public Vset checkValue(Environment env, Context ctx, Vset vset, Hashtable exp) {
68          vset = left.checkValue(env, ctx, vset, exp);
69          vset = right.checkValue(env, ctx, vset, exp);
70  
71          int tm = left.type.getTypeMask() | right.type.getTypeMask();
72          if ((tm & TM_ERROR) != 0) {
73              return vset;
74          }
75          selectType(env, ctx, tm);
76  
77          if (type.isType(TC_ERROR)) {
78              env.error(where, "invalid.args", opNames[op]);
79          }
80          return vset;
81      }
82  
83      /**
84       * Check if constant
85       */
86      public boolean isConstant() {
87          switch (op) {
88          case MUL:
89          case DIV:
90          case REM:
91          case ADD:
92          case SUB:
93          case LSHIFT:
94          case RSHIFT:
95          case URSHIFT:
96          case LT:
97          case LE:
98          case GT:
99          case GE:
100         case EQ:
101         case NE:
102         case BITAND:
103         case BITXOR:
104         case BITOR:
105         case AND:
106         case OR:
107             return left.isConstant() && right.isConstant();
108         }
109         return false;
110     }
111     /**
112      * Evaluate
113      */
114     Expression eval(int a, int b) {
115         return this;
116     }
117     Expression eval(long a, long b) {
118         return this;
119     }
120     Expression eval(float a, float b) {
121         return this;
122     }
123     Expression eval(double a, double b) {
124         return this;
125     }
126     Expression eval(boolean a, boolean b) {
127         return this;
128     }
129     Expression eval(String a, String b) {
130         return this;
131     }
132     Expression eval() {
133         // See also the eval() code in BinaryShiftExpression.java.
134         if (left.op == right.op) {
135             switch (left.op) {
136               case BYTEVAL:
137               case CHARVAL:
138               case SHORTVAL:
139               case INTVAL:
140                 return eval(((IntegerExpression)left).value, ((IntegerExpression)right).value);
141               case LONGVAL:
142                 return eval(((LongExpression)left).value, ((LongExpression)right).value);
143               case FLOATVAL:
144                 return eval(((FloatExpression)left).value, ((FloatExpression)right).value);
145               case DOUBLEVAL:
146                 return eval(((DoubleExpression)left).value, ((DoubleExpression)right).value);
147               case BOOLEANVAL:
148                 return eval(((BooleanExpression)left).value, ((BooleanExpression)right).value);
149               case STRINGVAL:
150                 return eval(((StringExpression)left).value, ((StringExpression)right).value);
151             }
152         }
153         return this;
154     }
155 
156     /**
157      * Inline
158      */
159     public Expression inline(Environment env, Context ctx) {
160         left = left.inline(env, ctx);
161         right = right.inline(env, ctx);
162         return (left == null) ? right : new CommaExpression(where, left, right);
163     }
164     public Expression inlineValue(Environment env, Context ctx) {
165         left = left.inlineValue(env, ctx);
166         right = right.inlineValue(env, ctx);
167         try {
168             return eval().simplify();
169         } catch (ArithmeticException e) {
170             // Got rid of this error message.  It isn't illegal to
171             // have a program which does a constant division by
172             // zero.  We return `this' to make the compiler to
173             // generate code here.
174             // (bugs 4019304, 4089107).
175             //
176             // env.error(where, "arithmetic.exception");
177             return this;
178         }
179     }
180 
181     /**
182      * Create a copy of the expression for method inlining
183      */
184     public Expression copyInline(Context ctx) {
185         BinaryExpression e = (BinaryExpression)clone();
186         if (left != null) {
187             e.left = left.copyInline(ctx);
188         }
189         if (right != null) {
190             e.right = right.copyInline(ctx);
191         }
192         return e;
193     }
194 
195     /**
196      * The cost of inlining this expression
197      */
198     public int costInline(int thresh, Environment env, Context ctx) {
199         return 1 + ((left != null) ? left.costInline(thresh, env, ctx) : 0) +
200                    ((right != null) ? right.costInline(thresh, env, ctx) : 0);
201     }
202 
203     /**
204      * Code
205      */
206     void codeOperation(Environment env, Context ctx, Assembler asm) {
207         throw new CompilerError("codeOperation: " + opNames[op]);
208     }
209     public void codeValue(Environment env, Context ctx, Assembler asm) {
210         if (type.isType(TC_BOOLEAN)) {
211             Label l1 = new Label();
212             Label l2 = new Label();
213 
214             codeBranch(env, ctx, asm, l1, true);
215             asm.add(true, where, opc_ldc, new Integer(0));
216             asm.add(true, where, opc_goto, l2);
217             asm.add(l1);
218             asm.add(true, where, opc_ldc, new Integer(1));
219             asm.add(l2);
220         } else {
221             left.codeValue(env, ctx, asm);
222             right.codeValue(env, ctx, asm);
223             codeOperation(env, ctx, asm);
224         }
225     }
226 
227     /**
228      * Print
229      */
230     public void print(PrintStream out) {
231         out.print("(" + opNames[op] + " ");
232         if (left != null) {
233             left.print(out);
234         } else {
235             out.print("<null>");
236         }
237         out.print(" ");
238         if (right != null) {
239             right.print(out);
240         } else {
241             out.print("<null>");
242         }
243         out.print(")");
244     }
245 }