1 /*
2 * Copyright (c) 2009, 2015, 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 jdk.vm.ci.code;
24
25 import java.nio.ByteOrder;
26
27 import jdk.vm.ci.code.Register.RegisterCategory;
28 import jdk.vm.ci.meta.JavaKind;
29 import jdk.vm.ci.meta.PlatformKind;
30
31 /**
32 * Represents a CPU architecture, including information such as its endianness, CPU registers, word
33 * width, etc.
34 */
35 public abstract class Architecture {
36
37 /**
38 * The architecture specific type of a native word.
39 */
40 private final PlatformKind wordKind;
41
42 /**
43 * The name of this architecture (e.g. "AMD64", "SPARCv9").
44 */
45 private final String name;
46
47 /**
48 * List of all available registers on this architecture. The index of each register in this list
49 * is equal to its {@linkplain Register#number number}.
50 */
51 private final RegisterArray registers;
52
53 /**
54 * The byte ordering can be either little or big endian.
55 */
56 private final ByteOrder byteOrder;
57
58 /**
59 * Whether the architecture supports unaligned memory accesses.
60 */
61 private final boolean unalignedMemoryAccess;
62
63 /**
64 * Mask of the barrier constants denoting the barriers that are not required to be explicitly
65 * inserted under this architecture.
66 */
67 private final int implicitMemoryBarriers;
68
69 /**
70 * Offset in bytes from the beginning of a call instruction to the displacement.
71 */
72 private final int machineCodeCallDisplacementOffset;
73
74 /**
75 * The size of the return address pushed to the stack by a call instruction. A value of 0
76 * denotes that call linkage uses registers instead (e.g. SPARC).
77 */
78 private final int returnAddressSize;
79
80 protected Architecture(String name, PlatformKind wordKind, ByteOrder byteOrder, boolean unalignedMemoryAccess, RegisterArray registers, int implicitMemoryBarriers,
81 int nativeCallDisplacementOffset,
82 int returnAddressSize) {
83 this.name = name;
84 this.registers = registers;
85 this.wordKind = wordKind;
86 this.byteOrder = byteOrder;
87 this.unalignedMemoryAccess = unalignedMemoryAccess;
88 this.implicitMemoryBarriers = implicitMemoryBarriers;
89 this.machineCodeCallDisplacementOffset = nativeCallDisplacementOffset;
90 this.returnAddressSize = returnAddressSize;
91 }
92
93 /**
94 * Converts this architecture to a string.
95 *
96 * @return the string representation of this architecture
97 */
98 @Override
99 public final String toString() {
100 return getName().toLowerCase();
101 }
102
103 /**
104 * Gets the natural size of words (typically registers and pointers) of this architecture, in
105 * bytes.
106 */
107 public int getWordSize() {
108 return wordKind.getSizeInBytes();
109 }
110
111 public PlatformKind getWordKind() {
112 return wordKind;
113 }
114
115 /**
116 * Gets the name of this architecture.
117 */
118 public String getName() {
119 return name;
120 }
121
122 /**
123 * Gets the list of all registers that exist on this architecture. This contains all registers
124 * that exist in the specification of this architecture. Not all of them may be available on
125 * this particular architecture instance. The index of each register in this list is equal to
126 * its {@linkplain Register#number number}.
127 */
128 public RegisterArray getRegisters() {
129 return registers;
130 }
131
132 /**
133 * Gets a list of all registers available for storing values on this architecture. This may be a
134 * subset of {@link #getRegisters()}, depending on the capabilities of this particular CPU.
135 */
136 public RegisterArray getAvailableValueRegisters() {
137 return getRegisters();
138 }
139
140 public ByteOrder getByteOrder() {
141 return byteOrder;
142 }
143
144 /**
145 * @return true if the architecture supports unaligned memory accesses.
146 */
147 public boolean supportsUnalignedMemoryAccess() {
148 return unalignedMemoryAccess;
149 }
150
151 /**
152 * Gets the size of the return address pushed to the stack by a call instruction. A value of 0
153 * denotes that call linkage uses registers instead.
154 */
155 public int getReturnAddressSize() {
156 return returnAddressSize;
157 }
158
159 /**
160 * Gets the offset in bytes from the beginning of a call instruction to the displacement.
161 */
162 public int getMachineCodeCallDisplacementOffset() {
163 return machineCodeCallDisplacementOffset;
164 }
165
166 /**
167 * Determines the barriers in a given barrier mask that are explicitly required on this
168 * architecture.
169 *
170 * @param barriers a mask of the barrier constants
171 * @return the value of {@code barriers} minus the barriers unnecessary on this architecture
172 */
173 public final int requiredBarriers(int barriers) {
174 return barriers & ~implicitMemoryBarriers;
175 }
176
177 /**
178 * Determine whether a kind can be stored in a register of a given category.
179 *
180 * @param category the category of the register
181 * @param kind the kind that should be stored in the register
182 */
183 public abstract boolean canStoreValue(RegisterCategory category, PlatformKind kind);
184
185 /**
186 * Return the largest kind that can be stored in a register of a given category.
187 *
188 * @param category the category of the register
189 * @return the largest kind that can be stored in a register {@code category}
190 */
191 public abstract PlatformKind getLargestStorableKind(RegisterCategory category);
192
193 /**
194 * Return the {@link PlatformKind} that is used to store values of a given {@link JavaKind}.
195 */
196 public abstract PlatformKind getPlatformKind(JavaKind javaKind);
197
198 @Override
199 public final boolean equals(Object obj) {
200 if (obj == this) {
201 return true;
202 }
203 if (obj instanceof Architecture) {
204 Architecture that = (Architecture) obj;
205 if (this.name.equals(that.name)) {
206 assert this.byteOrder.equals(that.byteOrder);
207 assert this.implicitMemoryBarriers == that.implicitMemoryBarriers;
208 assert this.machineCodeCallDisplacementOffset == that.machineCodeCallDisplacementOffset;
209 assert this.registers.equals(that.registers);
210 assert this.returnAddressSize == that.returnAddressSize;
211 assert this.unalignedMemoryAccess == that.unalignedMemoryAccess;
212 assert this.wordKind == that.wordKind;
213 return true;
214 }
215 }
216 return false;
217 }
218
219 @Override
220 public final int hashCode() {
221 return name.hashCode();
222 }
223 }