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comparison graal/GraalCompiler/src/com/sun/c1x/opt/InstructionSubstituter.java @ 2509:16b9a8b5ad39

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Renamings Runtime=>GraalRuntime and Compiler=>GraalCompiler
author Thomas Wuerthinger <thomas@wuerthinger.net>
date Wed, 27 Apr 2011 11:50:44 +0200
parents graal/Compiler/src/com/sun/c1x/opt/InstructionSubstituter.java@9ec15d6914ca
children
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2508:fea94949e0a2 2509:16b9a8b5ad39
1 /*
2 * Copyright (c) 2009, 2011, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package com.sun.c1x.opt;
24
25 import com.sun.c1x.ir.*;
26 import com.sun.c1x.value.*;
27 import com.sun.c1x.graph.IR;
28
29 /**
30 * This class allows instructions to be substituted within an IR graph. It allows
31 * registering substitutions and iterates over the instructions of a program and replaces
32 * the occurrence of each instruction with its substitution, if it has one.
33 *
34 * @author Ben L. Titzer
35 */
36 public final class InstructionSubstituter implements BlockClosure, ValueClosure {
37
38 final IR ir;
39 boolean hasSubstitution;
40
41 public InstructionSubstituter(IR ir) {
42 this.ir = ir;
43 }
44
45 public void apply(BlockBegin block) {
46 Instruction last = null;
47 if (block.exceptionHandlerStates() != null) {
48 for (FrameState s : block.exceptionHandlerStates()) {
49 s.valuesDo(this);
50 }
51 }
52 for (Instruction n = block; n != null; n = last.next()) {
53 n.allValuesDo(this);
54 if (n.subst != null && last != null) {
55 // this instruction has a substitution, skip it
56 last.resetNext(n.next());
57 } else {
58 last = n;
59 }
60 }
61 }
62
63 public void finish() {
64 if (hasSubstitution) {
65 ir.startBlock.iterateAnyOrder(this, false);
66 }
67 }
68
69 public boolean hasSubst(Value i) {
70 return i.subst != null;
71 }
72
73 public void setSubst(Value i, Value n) {
74 if (i == n) {
75 i.subst = null;
76 } else {
77 hasSubstitution = true;
78 i.subst = n;
79 }
80 }
81
82 public Value getSubst(Value i) {
83 Value p = i;
84 while (true) {
85 if (p.subst == null) {
86 break;
87 }
88 p = p.subst;
89 }
90 return p;
91 }
92
93 public Value apply(Value i) {
94 if (i != null) {
95 return getSubst(i);
96 }
97 return i;
98 }
99 }