1 cananian 1.1.2.1 // DATUM.java, created Fri Jul 23 13:39:22 1999 by duncan
2 cananian 1.1.2.1 // Copyright (C) 1998 Duncan Bryce <duncan@lcs.mit.edu>
3 cananian 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 cananian 1.1.2.1 package harpoon.IR.Tree;
5 cananian 1.1.2.1
6 cananian 1.1.2.1 import harpoon.ClassFile.HCodeElement;
7 cananian 1.1.2.3 import harpoon.Temp.TempMap;
8 cananian 1.1.2.1 import harpoon.Util.Util;
9 cananian 1.1.2.1
10 cananian 1.1.2.1 /**
11 cananian 1.1.2.1 * <code>DATUM</code> objects are statements which write a value to memory
12 cananian 1.1.2.1 * at the time when a program is loaded. The location written is
13 cananian 1.1.2.1 * calculated using this formula:
14 cananian 1.1.2.1 *
15 cananian 1.1.2.1 * <PRE>
16 cananian 1.1.2.1 * location = base + offset
17 cananian 1.1.2.1 *
18 cananian 1.1.2.1 * where
19 cananian 1.1.2.1 * base = location of nearest LABEL, l, which precedes this DATUM
20 cananian 1.1.2.1 * offset = the total size of all instructions between l and this DATUM
21 cananian 1.1.2.1 *
22 cananian 1.1.2.1 * </PRE>
23 cananian 1.1.2.1 *
24 cananian 1.1.2.1 * @author Duncan Bryce <duncan@lcs.mit.edu>
25 cananian 1.4 * @version $Id: DATUM.java,v 1.4 2002/04/10 03:05:44 cananian Exp $
26 cananian 1.1.2.1 */
27 cananian 1.1.2.1 public class DATUM extends Stm implements harpoon.ClassFile.HDataElement {
28 cananian 1.1.2.1 /** If false, the memory is not initialized; instead it is reserved
29 cananian 1.1.2.1 * with an unspecified value. */
30 cananian 1.1.2.1 public final boolean initialized;
31 cananian 1.1.2.1
32 cananian 1.1.2.1 /** Class constructor.
33 cananian 1.1.2.1 * The parameter <br><code>data</code> must be an instance of either
34 cananian 1.1.2.1 * <code>harpoon.IR.Tree.CONST</code> or
35 cananian 1.1.2.1 * <code>harpoon.IR.Tree.NAME</code>. Passing <code>null</code> for
36 cananian 1.1.2.1 * the parameter <code>data</code> reserves a word of memory at the
37 cananian 1.1.2.1 * location of this <code>DATUM</code> without assigning it a value.
38 cananian 1.1.2.1 */
39 cananian 1.1.2.1 public DATUM(TreeFactory tf, HCodeElement source, Exp data) {
40 cananian 1.1.2.2 super(tf, source, 1);
41 cananian 1.3.2.1 assert data!=null;
42 cananian 1.1.2.1 this.setData(data);
43 cananian 1.1.2.1 this.initialized = true;
44 cananian 1.3.2.1 assert data.kind()==TreeKind.CONST ||
45 cananian 1.3.2.1 data.kind()==TreeKind.NAME;
46 cananian 1.3.2.1 assert tf==data.tf : "Dest and Src must have same tree factory";
47 cananian 1.1.2.1 }
48 cananian 1.1.2.1
49 cananian 1.1.2.1 /** Class constructor.
50 cananian 1.1.2.1 * Reserves memory at the location of this <code>DATUM</code>
51 cananian 1.1.2.1 * of the size of the specified type without assigning it a value.
52 cananian 1.1.2.1 */
53 cananian 1.1.2.1 public DATUM(TreeFactory tf, HCodeElement source, int type) {
54 cananian 1.1.2.2 super(tf, source, 1);
55 cananian 1.3.2.1 assert Type.isValid(type);
56 cananian 1.1.2.1 if (type==Type.INT)
57 cananian 1.1.2.1 this.setData(new CONST(tf, source, (int)0));
58 cananian 1.1.2.1 else if (type==Type.LONG)
59 cananian 1.1.2.1 this.setData(new CONST(tf, source, (long)0));
60 cananian 1.1.2.1 else if (type==Type.FLOAT)
61 cananian 1.1.2.1 this.setData(new CONST(tf, source, (float)0));
62 cananian 1.1.2.1 else if (type==Type.DOUBLE)
63 cananian 1.1.2.1 this.setData(new CONST(tf, source, (double)0));
64 cananian 1.1.2.1 else if (type==Type.POINTER)
65 cananian 1.1.2.1 this.setData(new CONST(tf, source)); // null
66 cananian 1.1.2.1 else throw new Error("Impossible!");
67 cananian 1.1.2.1 this.initialized = false;
68 cananian 1.1.2.1 }
69 cananian 1.1.2.1
70 cananian 1.1.2.1 /** Class constructor.
71 cananian 1.1.2.1 * Reserves memory at the location of this <code>DATUM</code>
72 cananian 1.1.2.1 * of the specified small without assigning it a value.
73 cananian 1.1.2.1 */
74 cananian 1.1.2.1 public DATUM(TreeFactory tf, HCodeElement source,
75 cananian 1.1.2.1 int bitwidth, boolean signed) {
76 cananian 1.1.2.2 super(tf, source, 1);
77 cananian 1.1.2.1 this.setData(new CONST(tf, source, bitwidth, signed, 0));
78 cananian 1.1.2.1 this.initialized = false;
79 cananian 1.1.2.1 }
80 cananian 1.1.2.1
81 cananian 1.1.2.1 private DATUM(TreeFactory tf, HCodeElement source,
82 cananian 1.1.2.1 Exp data, boolean initialized) {
83 cananian 1.1.2.2 super(tf, source, 1);
84 cananian 1.1.2.1 this.setData(data);
85 cananian 1.1.2.1 this.initialized = initialized;
86 cananian 1.3.2.1 assert data.kind()==TreeKind.CONST ||
87 cananian 1.3.2.1 data.kind()==TreeKind.NAME;
88 cananian 1.3.2.1 assert tf==data.tf : "Dest and Src must have same tree factory";
89 cananian 1.1.2.1 }
90 cananian 1.1.2.1
91 cananian 1.1.2.2 /** Returns the expression to write to memory. Never null. */
92 cananian 1.1.2.2 public Exp getData() { return (Exp) getChild(0); }
93 cananian 1.1.2.1
94 cananian 1.1.2.2 /** Sets the expression to write to memory. Never null. */
95 cananian 1.1.2.2 public void setData(Exp data) { setChild(0, data); }
96 cananian 1.1.2.1
97 cananian 1.1.2.1 public int kind() { return TreeKind.DATUM; }
98 cananian 1.1.2.1
99 cananian 1.1.2.1 public Stm build(TreeFactory tf, ExpList kids) {
100 cananian 1.3.2.1 assert kids!=null && kids.tail==null;
101 cananian 1.3.2.1 assert kids.head == null || tf == kids.head.tf;
102 cananian 1.1.2.1 return new DATUM(tf, this, kids.head, initialized);
103 cananian 1.1.2.1 }
104 cananian 1.1.2.1
105 cananian 1.1.2.1 /** Accept a visitor */
106 cananian 1.1.2.1 public void accept(TreeVisitor v) { v.visit(this); }
107 cananian 1.1.2.1
108 cananian 1.1.2.3 public Tree rename(TreeFactory tf, TempMap tm, CloneCallback cb) {
109 cananian 1.1.2.4 return cb.callback(this, new DATUM(tf, this, (Exp)getData().rename(tf, tm, cb),initialized), tm);
110 cananian 1.1.2.1 }
111 cananian 1.1.2.1
112 cananian 1.1.2.1 public String toString() {
113 cananian 1.1.2.1 StringBuffer sb = new StringBuffer("DATUM<");
114 cananian 1.1.2.2 sb.append(getData() instanceof PreciselyTyped ?
115 cananian 1.1.2.2 Type.toString((PreciselyTyped)getData()) :
116 cananian 1.1.2.2 Type.toString(getData().type()));
117 cananian 1.1.2.1 sb.append(">(#"); sb.append(getID()); sb.append(")");
118 cananian 1.1.2.1 return sb.toString();
119 cananian 1.1.2.1 }
120 cananian 1.2 }