001    /*
002     *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003     *
004     *  This file is licensed to You under the Eclipse Public License (EPL);
005     *  You may not use this file except in compliance with the License. You
006     *  may obtain a copy of the License at
007     *
008     *      http://www.opensource.org/licenses/eclipse-1.0.php
009     *
010     *  See the COPYRIGHT.txt file distributed with this work for information
011     *  regarding copyright ownership.
012     */
013    package org.jikesrvm.compilers.opt.ir.operand;
014    
015    import org.jikesrvm.classloader.TypeReference;
016    import org.jikesrvm.compilers.opt.util.Bits;
017    import org.jikesrvm.runtime.Statics;
018    import org.vmmagic.unboxed.Offset;
019    
020    /**
021     * Represents a constant long operand.
022     *
023     * @see Operand
024     */
025    public final class LongConstantOperand extends ConstantOperand {
026    
027      /**
028       * Constant 0, can be copied as convenient
029       */
030      public static final LongConstantOperand zero =
031        new LongConstantOperand(0, Statics.slotAsOffset(Statics.findOrCreateLongSizeLiteral(0)));
032    
033      /**
034       * Value of this operand.
035       */
036      public long value;
037    
038      /**
039       * Offset in JTOC where this long constant lives. (0 for constants
040       * obtained from constant folding)
041       * TODO is this field still necessary?
042       */
043      public Offset offset;
044    
045      /**
046       * Constructs a new long constant operand with the specified value.
047       *
048       * @param v value
049       */
050      public LongConstantOperand(long v) {
051        value = v;
052        offset = Offset.zero();
053      }
054    
055      /**
056       * Constructs a new long constant operand with the specified value and JTOC offset.
057       * TODO is this constructor still necessary?
058       * @param v value
059       * @param i offset in the JTOC
060       */
061      public LongConstantOperand(long v, Offset i) {
062        value = v;
063        offset = i;
064      }
065    
066      /**
067       * @return {@link TypeReference#Long}
068       */
069      @Override
070      public TypeReference getType() {
071        return TypeReference.Long;
072      }
073    
074      /**
075       * @return <code>true</code>
076       */
077      @Override
078      public boolean isLong() {
079        return true;
080      }
081    
082      /**
083       * Return the lower 32 bits (as an int) of value
084       */
085      public int lower32() {
086        return Bits.lower32(value);
087      }
088    
089      /**
090       * Return the upper 32 bits (as an int) of value
091       */
092      public int upper32() {
093        return Bits.upper32(value);
094      }
095    
096      @Override
097      public Operand copy() {
098        return new LongConstantOperand(value, offset);
099      }
100    
101      @Override
102      public boolean similar(Operand op) {
103        return (op instanceof LongConstantOperand) && (value == ((LongConstantOperand) op).value);
104      }
105    
106      /**
107       * Returns the string representation of this operand.
108       *
109       * @return a string representation of this operand.
110       */
111      @Override
112      public String toString() {
113        return Long.toString(value) + "L";
114      }
115    
116    }