1 cananian 1.1.2.1 // MEM.java, created Wed Jan 13 21:14:57 1999 by cananian
2 cananian 1.1.2.13 // Copyright (C) 1998 C. Scott Ananian <cananian@alumni.princeton.edu>
3 cananian 1.1.2.13 // 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 1.1.2.5 import harpoon.ClassFile.HCodeElement;
7 cananian 1.1.2.24 import harpoon.Temp.TempMap;
8 cananian 1.1.2.4 import harpoon.Util.Util;
9 cananian 1.1.2.4
10 cananian 1.1.2.1 /**
11 cananian 1.1.2.1 * <code>MEM</code> objects are expressions which stand for the contents of
12 cananian 1.1.2.2 * a value in memory starting at the address specified by the
13 cananian 1.1.2.1 * subexpression. Note that when <code>MEM</code> is used as the left child
14 cananian 1.1.2.2 * of a <code>MOVE</code> or <code>CALL</code>, it means "store," but
15 cananian 1.1.2.2 * anywhere else it means "fetch."
16 cananian 1.1.2.1 *
17 cananian 1.1.2.1 * @author C. Scott Ananian <cananian@alumni.princeton.edu>, based on
18 cananian 1.1.2.1 * <i>Modern Compiler Implementation in Java</i> by Andrew Appel.
19 cananian 1.4 * @version $Id: MEM.java,v 1.4 2002/04/10 03:05:45 cananian Exp $
20 cananian 1.1.2.1 */
21 duncan 1.1.2.14 public class MEM extends Exp implements PreciselyTyped {
22 cananian 1.1.2.4 /** The type of this memory reference expression. */
23 cananian 1.1.2.22 public final int type;
24 duncan 1.1.2.14
25 cananian 1.1.2.17 // PreciselyTyped interface
26 cananian 1.1.2.17 public final boolean isSmall;
27 duncan 1.1.2.14 private int bitwidth = -1;
28 cananian 1.1.2.16 private boolean signed = true;
29 duncan 1.1.2.14
30 cananian 1.1.2.1 /** Constructor. */
31 cananian 1.1.2.5 public MEM(TreeFactory tf, HCodeElement source,
32 cananian 1.1.2.5 int type, Exp exp) {
33 cananian 1.1.2.23 super(tf, source, 1);
34 duncan 1.1.2.20 this.type=type; this.setExp(exp); this.isSmall=false;
35 cananian 1.3.2.1 assert Type.isValid(type) && exp!=null;
36 cananian 1.3.2.1 assert tf == exp.tf : "This and Exp must have same tree factory";
37 cananian 1.1.2.4 }
38 duncan 1.1.2.14
39 duncan 1.1.2.14 /** Creates a MEM with a precisely defined type.
40 duncan 1.1.2.14 * @param bitwidth the width in bits of this <code>MEM</code>'s type.
41 duncan 1.1.2.14 * Fails unless <code>0 <= bitwidth < 32</code>.
42 duncan 1.1.2.14 * @param signed whether this <code>MEM</code> is signed
43 duncan 1.1.2.14 * @param exp the location at which to load or store
44 duncan 1.1.2.14 */
45 duncan 1.1.2.14 public MEM(TreeFactory tf, HCodeElement source,
46 duncan 1.1.2.14 int bitwidth, boolean signed, Exp exp) {
47 cananian 1.1.2.23 super(tf, source, 1);
48 cananian 1.3.2.1 assert exp!=null;
49 duncan 1.1.2.20 this.type=INT; this.setExp(exp); this.isSmall=true;
50 duncan 1.1.2.14 this.bitwidth=bitwidth; this.signed=signed;
51 cananian 1.3.2.1 assert tf == exp.tf : "This and Exp must have same tree factory";
52 cananian 1.3.2.1 assert (0<=bitwidth)&&(bitwidth<32) : "Invalid bitwidth";
53 duncan 1.1.2.14 }
54 duncan 1.1.2.14
55 duncan 1.1.2.14 private MEM(TreeFactory tf, HCodeElement source, int type, Exp exp,
56 cananian 1.1.2.17 boolean isSmall, int bitwidth, boolean signed) {
57 cananian 1.1.2.23 super(tf, source, 1);
58 cananian 1.3.2.1 assert exp!=null;
59 duncan 1.1.2.20 this.type=type; this.setExp(exp); this.isSmall=isSmall;
60 duncan 1.1.2.14 this.bitwidth=bitwidth; this.signed=signed;
61 cananian 1.3.2.1 assert tf == exp.tf : "This and Exp must have same tree factory";
62 cananian 1.3.2.1 assert Type.isValid(type);
63 cananian 1.3.2.1 assert !isSmall || type==INT;
64 duncan 1.1.2.20 }
65 duncan 1.1.2.20
66 cananian 1.1.2.23 /** Returns a subexpression evaluating to a memory reference location. */
67 cananian 1.1.2.23 public Exp getExp() { return (Exp) getChild(0); }
68 duncan 1.1.2.20
69 cananian 1.1.2.23 /** Sets the memory reference subexpression. */
70 cananian 1.1.2.23 public void setExp(Exp exp) { setChild(0, exp); }
71 duncan 1.1.2.9
72 duncan 1.1.2.9 public int kind() { return TreeKind.MEM; }
73 duncan 1.1.2.9
74 duncan 1.1.2.12 public Exp build(TreeFactory tf, ExpList kids) {
75 cananian 1.3.2.1 assert tf == kids.head.tf;
76 cananian 1.3.2.1 assert kids.tail==null;
77 cananian 1.1.2.17 return new MEM(tf, this, type, kids.head, isSmall, bitwidth, signed);
78 cananian 1.1.2.4 }
79 cananian 1.1.2.2
80 cananian 1.1.2.2 // Typed interface:
81 cananian 1.3.2.1 public int type() { assert Type.isValid(type); return type; }
82 duncan 1.1.2.14
83 duncan 1.1.2.14 // PreciselyTyped interface:
84 cananian 1.1.2.17 /** Returns true if this is a sub-integer expression. */
85 cananian 1.1.2.17 public boolean isSmall() { return isSmall; }
86 cananian 1.1.2.16 /** Returns the size of the expression, in bits.
87 cananian 1.1.2.17 * Only valid if the <code>isSmall()==true</code>. */
88 cananian 1.3.2.1 public int bitwidth() { assert type==INT&&isSmall; return bitwidth; }
89 cananian 1.1.2.16 /** Returns true if this is a signed expression, false otherwise.
90 cananian 1.1.2.17 * Only valid if the <code>isSmall()==true</code>. */
91 cananian 1.3.2.1 public boolean signed() { assert type==INT&&isSmall; return signed; }
92 cananian 1.1.2.4
93 duncan 1.1.2.3 /** Accept a visitor */
94 cananian 1.1.2.18 public void accept(TreeVisitor v) { v.visit(this); }
95 duncan 1.1.2.7
96 cananian 1.1.2.24 public Tree rename(TreeFactory tf, TempMap tm, CloneCallback cb) {
97 cananian 1.1.2.24 return cb.callback(this, new MEM(tf, this, type,
98 cananian 1.1.2.24 (Exp)getExp().rename(tf, tm, cb),
99 cananian 1.1.2.25 isSmall, bitwidth, signed),
100 cananian 1.1.2.25 tm);
101 andyb 1.1.2.8 }
102 andyb 1.1.2.8
103 andyb 1.1.2.8 public String toString() {
104 cananian 1.1.2.23 return "MEM<" + Type.toString(this) + ">(#" + getExp().getID() + ")";
105 duncan 1.1.2.7 }
106 cananian 1.1.2.1 }
107 cananian 1.2