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comparison graal/com.oracle.max.cri/src/com/sun/cri/ci/CiAddress.java @ 3733:e233f5660da4

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Added Java files from Maxine project.
author Thomas Wuerthinger <thomas.wuerthinger@oracle.com>
date Sat, 17 Dec 2011 19:59:18 +0100
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children bc8527f3071c
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3732:3e2e8b8abdaf 3733:e233f5660da4
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.cri.ci;
24
25 /**
26 * Represents an address in target machine memory, specified via some combination of a base register, an index register,
27 * a displacement and a scale. Note that the base and index registers may be {@link CiVariable variable}, that is as yet
28 * unassigned to target machine registers.
29 */
30 public final class CiAddress extends CiValue {
31
32 /**
33 * A sentinel value used as a place holder in an instruction stream for an address that will be patched.
34 */
35 public static final CiAddress Placeholder = new CiAddress(CiKind.Illegal, CiRegister.None.asValue());
36
37 /**
38 * Base register that defines the start of the address computation; always present.
39 */
40 public final CiValue base;
41 /**
42 * Optional index register, the value of which (possibly scaled by {@link #scale}) is added to {@link #base}.
43 * If not present, is denoted by {@link CiValue#IllegalValue}.
44 */
45 public final CiValue index;
46 /**
47 * Scaling factor for indexing, dependent on target operand size.
48 */
49 public final Scale scale;
50 /**
51 * Optional additive displacement.
52 */
53 public final int displacement;
54
55 /**
56 * Creates a {@code CiAddress} with given base register, no scaling and no displacement.
57 * @param kind the kind of the value being addressed
58 * @param base the base register
59 */
60 public CiAddress(CiKind kind, CiValue base) {
61 this(kind, base, IllegalValue, Scale.Times1, 0);
62 }
63
64 /**
65 * Creates a {@code CiAddress} with given base register, no scaling and a given displacement.
66 * @param kind the kind of the value being addressed
67 * @param base the base register
68 * @param displacement the displacement
69 */
70 public CiAddress(CiKind kind, CiValue base, int displacement) {
71 this(kind, base, IllegalValue, Scale.Times1, displacement);
72 }
73
74 /**
75 * Creates a {@code CiAddress} with given base and offset registers, no scaling and no displacement.
76 * @param kind the kind of the value being addressed
77 * @param base the base register
78 * @param offset the offset register
79 */
80 public CiAddress(CiKind kind, CiValue base, CiValue offset) {
81 this(kind, base, offset, Scale.Times1, 0);
82 }
83
84 /**
85 * Creates a {@code CiAddress} with given base and index registers, scaling and displacement.
86 * This is the most general constructor..
87 * @param kind the kind of the value being addressed
88 * @param base the base register
89 * @param index the index register
90 * @param scale the scaling factor
91 * @param displacement the displacement
92 */
93 public CiAddress(CiKind kind, CiValue base, CiValue index, Scale scale, int displacement) {
94 super(kind);
95
96 if (index.isConstant()) {
97 long longIndex = ((CiConstant) index).asLong();
98 long longDisp = displacement + longIndex * scale.value;
99 if ((int) longIndex != longIndex || (int) longDisp != longDisp) {
100 throw new Error("integer overflow when computing constant displacement");
101 }
102 displacement = (int) longDisp;
103 index = IllegalValue;
104 scale = Scale.Times1;
105 }
106 assert base.isIllegal() || base.isVariableOrRegister();
107 assert index.isIllegal() || index.isVariableOrRegister();
108
109 this.base = base;
110 this.index = index;
111 this.scale = scale;
112 this.displacement = displacement;
113 }
114
115 /**
116 * A scaling factor used in complex addressing modes such as those supported by x86 platforms.
117 */
118 public enum Scale {
119 Times1(1, 0),
120 Times2(2, 1),
121 Times4(4, 2),
122 Times8(8, 3);
123
124 Scale(int value, int log2) {
125 this.value = value;
126 this.log2 = log2;
127 }
128
129 /**
130 * The value (or multiplier) of this scale.
131 */
132 public final int value;
133
134 /**
135 * The {@linkplain #value value} of this scale log 2.
136 */
137 public final int log2;
138
139 public static Scale fromInt(int scale) {
140 // Checkstyle: stop
141 switch (scale) {
142 case 1: return Times1;
143 case 2: return Times2;
144 case 4: return Times4;
145 case 8: return Times8;
146 default: throw new IllegalArgumentException(String.valueOf(scale));
147 }
148 // Checkstyle: resume
149 }
150
151 public static Scale fromShift(int shift) {
152 return fromInt(1 << shift);
153 }
154 }
155
156 /**
157 * If the base register is a {@link CiRegisterValue} returns the associated {@link CiRegister}
158 * otherwise raises an exception..
159 * @return the base {@link CiRegister}
160 * @exception Error if {@code base} is not a {@link CiRegisterValue}
161 */
162 public CiRegister base() {
163 return base.asRegister();
164 }
165
166 /**
167 * If the index register is a {@link CiRegisterValue} returns the associated {@link CiRegister}
168 * otherwise raises an exception..
169 * @return the base {@link CiRegister}
170 * @exception Error if {@code index} is not a {@link CiRegisterValue}
171 */
172 public CiRegister index() {
173 return index.asRegister();
174 }
175
176 /**
177 * Encodes the possible addressing modes as a simple value.
178 */
179 public enum Format {
180 BASE,
181 BASE_DISP,
182 BASE_INDEX,
183 BASE_INDEX_DISP,
184 PLACEHOLDER;
185 }
186
187 /**
188 * Returns the {@link Format encoded addressing mode} that this {@code CiAddress} represents.
189 * @return the encoded addressing mode
190 */
191 public Format format() {
192 if (this == Placeholder) {
193 return Format.PLACEHOLDER;
194 }
195 assert base.isLegal();
196 if (index.isLegal()) {
197 if (displacement != 0) {
198 return Format.BASE_INDEX_DISP;
199 } else {
200 return Format.BASE_INDEX;
201 }
202 } else {
203 if (displacement != 0) {
204 return Format.BASE_DISP;
205 } else {
206 return Format.BASE;
207 }
208 }
209 }
210
211 private static String s(CiValue location) {
212 if (location.isRegister()) {
213 return location.asRegister().name;
214 }
215 assert location.isVariable();
216 return "v" + ((CiVariable) location).index;
217 }
218
219 private static String signed(int i) {
220 if (i >= 0) {
221 return "+" + i;
222 }
223 return String.valueOf(i);
224 }
225
226 @Override
227 public String name() {
228 // Checkstyle: stop
229 switch (format()) {
230 case BASE : return "[" + s(base) + "]";
231 case BASE_DISP : return "[" + s(base) + signed(displacement) + "]";
232 case BASE_INDEX : return "[" + s(base) + "+" + s(index) + "]";
233 case BASE_INDEX_DISP : return "[" + s(base) + "+(" + s(index) + "*" + scale.value + ")" + signed(displacement) + "]";
234 case PLACEHOLDER : return "[<placeholder>]";
235 default : throw new IllegalArgumentException("unknown format: " + format());
236 }
237 // Checkstyle: resume
238 }
239
240 @Override
241 public boolean equals(Object obj) {
242 if (obj instanceof CiAddress) {
243 CiAddress addr = (CiAddress) obj;
244 return kind == addr.kind && displacement == addr.displacement && base.equals(addr.base) && scale == addr.scale && index.equals(addr.index);
245 }
246 return false;
247 }
248
249 @Override
250 public boolean equalsIgnoringKind(CiValue o) {
251 if (o instanceof CiAddress) {
252 CiAddress addr = (CiAddress) o;
253 return displacement == addr.displacement && base.equalsIgnoringKind(addr.base) && scale == addr.scale && index.equalsIgnoringKind(addr.index);
254 }
255 return false;
256 }
257
258 @Override
259 public int hashCode() {
260 return (base.hashCode() << 4) | kind.ordinal();
261 }
262 }