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comparison graal/GraalCompiler/src/com/sun/c1x/opt/UnsafeCastEliminator.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/UnsafeCastEliminator.java@9ec15d6914ca
children
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2508:fea94949e0a2 2509:16b9a8b5ad39
1 /*
2 * Copyright (c) 2010, 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.graph.*;
26 import com.sun.c1x.ir.*;
27 import com.sun.c1x.value.*;
28
29 /**
30 * A mechanism to remove {@linkplain UnsafeCast#redundant redundant} unsafe casts.
31 *
32 * @author Doug Simon
33 */
34 public class UnsafeCastEliminator implements ValueClosure, BlockClosure {
35
36 final IR ir;
37
38 /**
39 * Eliminates redundant unsafe casts from a given IR.
40 */
41 public UnsafeCastEliminator(IR ir) {
42 this.ir = ir;
43 ir.startBlock.iterateAnyOrder(this, false);
44 }
45
46 public void apply(BlockBegin block) {
47 if (block.isExceptionEntry()) {
48 for (FrameState ehState : block.exceptionHandlerStates()) {
49 ehState.valuesDo(this);
50 }
51 }
52
53 Instruction i = block;
54 while (i != null) {
55 FrameState stateBefore = i.stateBefore();
56 if (stateBefore != null) {
57 stateBefore.valuesDo(this);
58 }
59 i.inputValuesDo(this);
60 FrameState stateAfter = i.stateAfter();
61 if (stateAfter != null) {
62 stateAfter.valuesDo(this);
63 }
64 i = i.next();
65 }
66 }
67
68 public Value apply(Value i) {
69 if (i instanceof UnsafeCast) {
70 Value y = ((UnsafeCast) i).nonRedundantReplacement();
71 assert y != null;
72 return y;
73 }
74 return i;
75 }
76 }