1 kkz 1.1.2.1 // WriteBarrierConstElim.java, created Thu Aug 23 20:20:34 2001 by kkz
2 kkz 1.1.2.1 // Copyright (C) 2000 Karen Zee <kkz@tmi.lcs.mit.edu>
3 kkz 1.1.2.1 // Licensed under the terms of the GNU GPL; see COPYING for details.
4 kkz 1.1.2.1 package harpoon.Analysis.PreciseGC;
5 kkz 1.1.2.1
6 kkz 1.1.2.1 import harpoon.Analysis.Tree.Canonicalize;
7 kkz 1.1.2.1 import harpoon.Analysis.Tree.ConstantPropagation;
8 kkz 1.1.2.1 import harpoon.Backend.Generic.Frame;
9 kkz 1.1.2.1 import harpoon.Backend.Maps.NameMap;
10 kkz 1.5 import harpoon.ClassFile.HClass;
11 kkz 1.1.2.1 import harpoon.ClassFile.HCode;
12 kkz 1.1.2.1 import harpoon.ClassFile.HCodeEdge;
13 kkz 1.1.2.1 import harpoon.ClassFile.HCodeFactory;
14 kkz 1.1.2.1 import harpoon.ClassFile.HMethod;
15 kkz 1.5 import harpoon.ClassFile.Linker;
16 kkz 1.1.2.1 import harpoon.IR.Properties.CFGrapher;
17 kkz 1.1.2.1 import harpoon.IR.Tree.CALL;
18 kkz 1.1.2.1 import harpoon.IR.Tree.CanonicalTreeCode;
19 kkz 1.1.2.1 import harpoon.IR.Tree.CONST;
20 kkz 1.1.2.1 import harpoon.IR.Tree.DerivationGenerator;
21 kkz 1.1.2.1 import harpoon.IR.Tree.Exp;
22 kkz 1.1.2.1 import harpoon.IR.Tree.ExpList;
23 kkz 1.1.2.1 import harpoon.IR.Tree.EXPR;
24 kkz 1.1.2.1 import harpoon.IR.Tree.LABEL;
25 kkz 1.1.2.1 import harpoon.IR.Tree.MOVE;
26 kkz 1.1.2.1 import harpoon.IR.Tree.NAME;
27 kkz 1.1.2.1 import harpoon.IR.Tree.Print;
28 kkz 1.1.2.1 import harpoon.IR.Tree.Stm;
29 kkz 1.1.2.1 import harpoon.IR.Tree.Tree;
30 kkz 1.1.2.1 import harpoon.IR.Tree.TreeFactory;
31 kkz 1.1.2.1 import harpoon.Temp.Label;
32 kkz 1.1.2.1 import harpoon.Util.Util;
33 kkz 1.1.2.1
34 kkz 1.1.2.1 import java.util.Arrays;
35 kkz 1.1.2.1 import java.util.List;
36 kkz 1.1.2.1
37 kkz 1.1.2.1 /**
38 kkz 1.5 * <code>WriteBarrierConstElim</code> operates on <code>Tree</code> form.
39 kkz 1.5 * It eliminates write barriers on MOVEs that are assigned from constants.
40 kkz 1.5 * Constant propagation should probably be run beforehand for this pass to
41 kkz 1.5 * make a difference.
42 kkz 1.1.2.1 * <p>
43 kkz 1.5 * If <code>WriteBarrierTreePass</code> is being used, it should be not be run
44 kkz 1.5 * until after this pass.
45 kkz 1.1.2.1 *
46 kkz 1.1.2.1 * @author Karen Zee <kkz@tmi.lcs.mit.edu>
47 cananian 1.6 * @version $Id: WriteBarrierConstElim.java,v 1.6 2003/03/11 19:15:41 cananian Exp $
48 kkz 1.1.2.1 */
49 kkz 1.1.2.1 public abstract class WriteBarrierConstElim extends
50 kkz 1.1.2.1 harpoon.Analysis.Tree.Simplification {
51 kkz 1.1.2.1
52 kkz 1.1.2.1 // hide constructor
53 kkz 1.1.2.1 private WriteBarrierConstElim() { }
54 kkz 1.1.2.1
55 kkz 1.1.2.1 /** Code factory for applying <code>WriteBarrierConstElim/code>
56 kkz 1.1.2.1 * to a canonical tree. Clones the tree before doing
57 kkz 1.1.2.1 * transformation in-place. */
58 kkz 1.5 public static HCodeFactory codeFactory(final Frame f,
59 kkz 1.5 final HCodeFactory parent,
60 kkz 1.5 final Linker linker) {
61 kkz 1.5 HClass WBC = linker.forName("harpoon.Runtime.PreciseGC.WriteBarrier");
62 kkz 1.5 HClass JLO = linker.forName("java.lang.Object");
63 kkz 1.5 HClass JLRF = linker.forName("java.lang.reflect.Field");
64 kkz 1.5 final HMethod arrayHM = WBC.getMethod("asc", new HClass[]
65 kkz 1.5 {JLO,HClass.Int,JLO,HClass.Int});
66 kkz 1.5 final HMethod fieldHM = WBC.getMethod("fsc", new HClass[]
67 kkz 1.5 {JLO,JLRF,JLO,HClass.Int});
68 cananian 1.3.2.1 assert parent.getCodeName().equals(CanonicalTreeCode.codename);
69 kkz 1.1.2.1 return Canonicalize.codeFactory(new HCodeFactory() {
70 kkz 1.1.2.1 public HCode convert(HMethod m) {
71 kkz 1.1.2.1 HCode hc = parent.convert(m);
72 kkz 1.1.2.1 if (hc!=null) {
73 kkz 1.1.2.1 harpoon.IR.Tree.Code code = (harpoon.IR.Tree.Code) hc;
74 kkz 1.1.2.1 // clone code...
75 kkz 1.1.2.1 code = (harpoon.IR.Tree.Code) code.clone(m).hcode();
76 kkz 1.1.2.1 DerivationGenerator dg = null;
77 kkz 1.1.2.1 try {
78 kkz 1.1.2.1 dg = (DerivationGenerator) code.getTreeDerivation();
79 kkz 1.1.2.1 } catch (ClassCastException ex) { /* i guess not */ }
80 kkz 1.1.2.1 // ...do analysis and modify cloned code in-place.
81 kkz 1.1.2.1 simplify((Stm)code.getRootElement(), dg,
82 kkz 1.1.2.1 HCE_RULES(code, f, arrayHM, fieldHM));
83 kkz 1.1.2.1 hc = code;
84 kkz 1.1.2.1 }
85 kkz 1.1.2.1 return hc;
86 kkz 1.1.2.1 }
87 kkz 1.1.2.1 public String getCodeName() { return parent.getCodeName(); }
88 kkz 1.1.2.1 public void clear(HMethod m) { parent.clear(m); }
89 kkz 1.1.2.1 });
90 kkz 1.1.2.1 }
91 kkz 1.1.2.1
92 cananian 1.6 public static List<Rule> HCE_RULES(final harpoon.IR.Tree.Code code,
93 kkz 1.1.2.1 final Frame f,
94 kkz 1.1.2.1 final HMethod arrayHM,
95 kkz 1.1.2.1 final HMethod fieldHM) {
96 kkz 1.1.2.1 final NameMap nm = f.getRuntime().getNameMap();
97 kkz 1.1.2.1 final Label LarrayHM = nm.label(arrayHM);
98 kkz 1.1.2.1 final Label LfieldHM = nm.label(fieldHM);
99 kkz 1.1.2.1 final CFGrapher cfgr = code.getGrapher();
100 kkz 1.1.2.1 // now make rules
101 kkz 1.1.2.1 return Arrays.asList(new Rule[] {
102 kkz 1.1.2.1 new Rule("removeBarriers") {
103 kkz 1.1.2.1 public boolean match(Stm stm) {
104 kkz 1.1.2.1 if (!contains(_KIND(stm), _CALL)) return false;
105 kkz 1.1.2.1 CALL call = (CALL) stm;
106 kkz 1.1.2.1 if (!contains(_KIND(call.getFunc()), _NAME)) return false;
107 kkz 1.1.2.1 NAME n = (NAME) call.getFunc();
108 kkz 1.1.2.1 if (!n.label.equals(LarrayHM) && !n.label.equals(LfieldHM))
109 kkz 1.1.2.1 return false;
110 kkz 1.1.2.1 // now check if we need the write barrier
111 kkz 1.1.2.1 ExpList explist = call.getArgs();
112 kkz 1.1.2.1 // get to the third argument
113 kkz 1.1.2.1 explist = explist.tail;
114 kkz 1.1.2.1 explist = explist.tail;
115 kkz 1.1.2.1 Exp val = explist.head;
116 kkz 1.1.2.1 return (contains(_KIND(val), _CONST|_NAME));
117 kkz 1.1.2.1 }
118 kkz 1.1.2.1 public Stm apply(TreeFactory tf, Stm stm,
119 kkz 1.1.2.1 DerivationGenerator dg) {
120 kkz 1.1.2.1 // we can get rid of the barrier
121 kkz 1.1.2.1 return new EXPR(tf, stm, new CONST(tf, null));
122 kkz 1.1.2.1 }
123 kkz 1.1.2.1 }
124 kkz 1.1.2.1 });
125 kkz 1.1.2.1 }
126 cananian 1.2 }