Mercurial > hg > graal-jvmci-8
comparison graal/Compiler/src/com/sun/c1x/ir/Value.java @ 2507:9ec15d6914ca
Pull over of compiler from maxine repository.
author | Thomas Wuerthinger <thomas@wuerthinger.net> |
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date | Wed, 27 Apr 2011 11:43:22 +0200 |
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2506:4a3bf8a5bf41 | 2507:9ec15d6914ca |
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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.ir; | |
24 | |
25 import static com.sun.c1x.ir.Value.Flag.*; | |
26 | |
27 import com.sun.c1x.*; | |
28 import com.sun.c1x.debug.*; | |
29 import com.sun.c1x.opt.*; | |
30 import com.sun.cri.ci.*; | |
31 import com.sun.cri.ri.*; | |
32 | |
33 /** | |
34 * This class represents a value within the HIR graph, including local variables, phis, and | |
35 * all other instructions. | |
36 * | |
37 * @author Ben L. Titzer | |
38 */ | |
39 public abstract class Value { | |
40 /** | |
41 * An enumeration of flags on values. | |
42 */ | |
43 public enum Flag { | |
44 NonNull, // this value is non-null | |
45 | |
46 NoNullCheck, // does not require null check | |
47 NoStoreCheck, // does not require store check | |
48 NoBoundsCheck, // does not require bounds check | |
49 NoZeroCheck, // divide or modulus cannot cause exception | |
50 | |
51 NoReadBarrier, // does not require read barrier | |
52 NoWriteBarrier, // does not require write barrier | |
53 NoDivSpecialCase, // divide or modulus cannot be special case of MIN_INT / -1 | |
54 DirectCompare, | |
55 IsLoaded, // field or method is resolved and class is loaded and initialized | |
56 IsStatic, // field or method access is static | |
57 IsSafepoint, // branch is backward (safepoint) | |
58 IsStrictFP, | |
59 PreservesState, // intrinsic preserves state | |
60 UnorderedIsTrue, | |
61 NeedsPatching, | |
62 LiveValue, // live because value is used | |
63 LiveDeopt, // live for deoptimization | |
64 LiveControl, // live for control dependencies | |
65 LiveSideEffect, // live for possible side-effects only | |
66 LiveStore, // instruction is a store | |
67 PhiDead, // phi is illegal because local is dead | |
68 PhiCannotSimplify, // phi cannot be simplified | |
69 PhiVisited, // phi has been visited during simplification | |
70 | |
71 ResultIsUnique; // the result of this instruction is guaranteed to be unique (e.g. a new object) | |
72 | |
73 public final int mask = 1 << ordinal(); | |
74 } | |
75 | |
76 private static final int LIVE_FLAGS = Flag.LiveValue.mask | | |
77 Flag.LiveDeopt.mask | | |
78 Flag.LiveControl.mask | | |
79 Flag.LiveSideEffect.mask; | |
80 /** | |
81 * The kind of this value. This is {@link CiKind#Void} for instructions that produce no value. | |
82 * This kind is guaranteed to be a {@linkplain CiKind#stackKind() stack kind}. | |
83 */ | |
84 public final CiKind kind; | |
85 | |
86 /** | |
87 * Unique identifier for this value. This field's value is lazily initialized by {@link #id()}. | |
88 */ | |
89 private int id; | |
90 | |
91 /** | |
92 * A mask of {@linkplain Flag flags} denoting extra properties of this value. | |
93 */ | |
94 private int flags; | |
95 | |
96 protected CiValue operand = CiValue.IllegalValue; | |
97 | |
98 /** | |
99 * A cache for analysis information. Every optimization must reset this field to {@code null} once it has completed. | |
100 */ | |
101 public Object optInfo; | |
102 | |
103 /** | |
104 * Used by {@link InstructionSubstituter}. | |
105 */ | |
106 public Value subst; | |
107 | |
108 public abstract BlockBegin block(); | |
109 | |
110 /** | |
111 * Creates a new value with the specified kind. | |
112 * @param kind the type of this value | |
113 */ | |
114 public Value(CiKind kind) { | |
115 assert kind == kind.stackKind() : kind + " != " + kind.stackKind(); | |
116 this.kind = kind; | |
117 } | |
118 | |
119 /** | |
120 * Checks whether this instruction is live (i.e. code should be generated for it). | |
121 * This is computed in a dedicated pass by {@link LivenessMarker}. | |
122 * An instruction is live because its value is needed by another live instruction, | |
123 * because its value is needed for deoptimization, or the program is control dependent | |
124 * upon it. | |
125 * @return {@code true} if this instruction should be considered live | |
126 */ | |
127 public final boolean isLive() { | |
128 return C1XOptions.PinAllInstructions || (flags & LIVE_FLAGS) != 0; | |
129 } | |
130 | |
131 /** | |
132 * Clears all liveness flags. | |
133 */ | |
134 public final void clearLive() { | |
135 flags = flags & ~LIVE_FLAGS; | |
136 } | |
137 | |
138 /** | |
139 * Gets the instruction that should be substituted for this one. Note that this | |
140 * method is recursive; if the substituted instruction has a substitution, then | |
141 * the final substituted instruction will be returned. If there is no substitution | |
142 * for this instruction, {@code this} will be returned. | |
143 * @return the substitution for this instruction | |
144 */ | |
145 public final Value subst() { | |
146 if (subst == null) { | |
147 return this; | |
148 } | |
149 return subst.subst(); | |
150 } | |
151 | |
152 /** | |
153 * Checks whether this instruction has a substitute. | |
154 * @return {@code true} if this instruction has a substitution. | |
155 */ | |
156 public final boolean hasSubst() { | |
157 return subst != null; | |
158 } | |
159 | |
160 /** | |
161 * Eliminates a given runtime check for this instruction. | |
162 * | |
163 * @param flag the flag representing the (elimination of the) runtime check | |
164 */ | |
165 public final void clearRuntimeCheck(Flag flag) { | |
166 if (!checkFlag(flag)) { | |
167 setFlag(flag); | |
168 runtimeCheckCleared(); | |
169 if (flag == NoNullCheck) { | |
170 C1XMetrics.NullCheckEliminations++; | |
171 } else if (flag == NoBoundsCheck) { | |
172 C1XMetrics.BoundsChecksElminations++; | |
173 } else if (flag == NoStoreCheck) { | |
174 C1XMetrics.StoreCheckEliminations++; | |
175 } else if (flag != NoZeroCheck) { | |
176 throw new InternalError("Unknown runtime check: " + flag); | |
177 } | |
178 } | |
179 } | |
180 | |
181 | |
182 /** | |
183 * Clear any internal state related to null checks, because a null check | |
184 * for this instruction is redundant. The state cleared may depend | |
185 * on the type of this instruction | |
186 */ | |
187 public final void eliminateNullCheck() { | |
188 clearRuntimeCheck(NoNullCheck); | |
189 } | |
190 | |
191 /** | |
192 * Notifies this instruction that a runtime check has been | |
193 * eliminated or made redundant. | |
194 */ | |
195 protected void runtimeCheckCleared() { | |
196 } | |
197 | |
198 /** | |
199 * Check whether this instruction has the specified flag set. | |
200 * @param flag the flag to test | |
201 * @return {@code true} if this instruction has the flag | |
202 */ | |
203 public final boolean checkFlag(Flag flag) { | |
204 return (flags & flag.mask) != 0; | |
205 } | |
206 | |
207 /** | |
208 * Set a flag on this instruction. | |
209 * @param flag the flag to set | |
210 */ | |
211 public final void setFlag(Flag flag) { | |
212 flags |= flag.mask; | |
213 } | |
214 | |
215 /** | |
216 * Clear a flag on this instruction. | |
217 * @param flag the flag to set | |
218 */ | |
219 public final void clearFlag(Flag flag) { | |
220 flags &= ~flag.mask; | |
221 } | |
222 | |
223 /** | |
224 * Set or clear a flag on this instruction. | |
225 * @param flag the flag to set | |
226 * @param val if {@code true}, set the flag, otherwise clear it | |
227 */ | |
228 public final void setFlag(Flag flag, boolean val) { | |
229 if (val) { | |
230 setFlag(flag); | |
231 } else { | |
232 clearFlag(flag); | |
233 } | |
234 } | |
235 | |
236 /** | |
237 * Initialize a flag on this instruction. Assumes the flag is not initially set, | |
238 * e.g. in the constructor of an instruction. | |
239 * @param flag the flag to set | |
240 * @param val if {@code true}, set the flag, otherwise do nothing | |
241 */ | |
242 public final void initFlag(Flag flag, boolean val) { | |
243 if (val) { | |
244 setFlag(flag); | |
245 } | |
246 } | |
247 | |
248 /** | |
249 * Checks whether this instruction produces a value which is guaranteed to be non-null. | |
250 * @return {@code true} if this instruction's value is not null | |
251 */ | |
252 public final boolean isNonNull() { | |
253 return checkFlag(Flag.NonNull); | |
254 } | |
255 | |
256 /** | |
257 * Checks whether this instruction needs a null check. | |
258 * @return {@code true} if this instruction needs a null check | |
259 */ | |
260 public final boolean needsNullCheck() { | |
261 return !checkFlag(Flag.NoNullCheck); | |
262 } | |
263 | |
264 /** | |
265 * Checks whether this value is a constant (i.e. it is of type {@link Constant}. | |
266 * @return {@code true} if this value is a constant | |
267 */ | |
268 public final boolean isConstant() { | |
269 return this instanceof Constant; | |
270 } | |
271 | |
272 /** | |
273 * Checks whether this value represents the null constant. | |
274 * @return {@code true} if this value represents the null constant | |
275 */ | |
276 public final boolean isNullConstant() { | |
277 return this instanceof Constant && ((Constant) this).value.isNull(); | |
278 } | |
279 | |
280 /** | |
281 * Checks whether this instruction "is illegal"--i.e. it represents a dead | |
282 * phi or an instruction which does not produce a value. | |
283 * @return {@code true} if this instruction is illegal as an input value to another instruction | |
284 */ | |
285 public final boolean isIllegal() { | |
286 return checkFlag(Flag.PhiDead); | |
287 } | |
288 | |
289 /** | |
290 * Convert this value to a constant if it is a constant, otherwise return null. | |
291 * @return the {@link CiConstant} represented by this value if it is a constant; {@code null} | |
292 * otherwise | |
293 */ | |
294 public final CiConstant asConstant() { | |
295 if (this instanceof Constant) { | |
296 return ((Constant) this).value; | |
297 } | |
298 return null; | |
299 } | |
300 | |
301 /** | |
302 * Gets the LIR operand associated with this instruction. | |
303 * @return the LIR operand for this instruction | |
304 */ | |
305 public final CiValue operand() { | |
306 return operand; | |
307 } | |
308 | |
309 /** | |
310 * Sets the LIR operand associated with this instruction. | |
311 * @param operand the operand to associate with this instruction | |
312 */ | |
313 public final void setOperand(CiValue operand) { | |
314 assert this.operand.isIllegal() : "operand cannot be set twice"; | |
315 assert operand != null && operand.isLegal() : "operand must be legal"; | |
316 assert operand.kind.stackKind() == this.kind; | |
317 this.operand = operand; | |
318 } | |
319 | |
320 /** | |
321 * Clears the LIR operand associated with this instruction. | |
322 */ | |
323 public final void clearOperand() { | |
324 this.operand = CiValue.IllegalValue; | |
325 } | |
326 | |
327 /** | |
328 * Computes the exact type of the result of this instruction, if possible. | |
329 * @return the exact type of the result of this instruction, if it is known; {@code null} otherwise | |
330 */ | |
331 public RiType exactType() { | |
332 return null; // default: unknown exact type | |
333 } | |
334 | |
335 /** | |
336 * Computes the declared type of the result of this instruction, if possible. | |
337 * @return the declared type of the result of this instruction, if it is known; {@code null} otherwise | |
338 */ | |
339 public RiType declaredType() { | |
340 return null; // default: unknown declared type | |
341 } | |
342 | |
343 /** | |
344 * Apply the specified closure to all the input values of this instruction. | |
345 * @param closure the closure to apply | |
346 */ | |
347 public void inputValuesDo(ValueClosure closure) { | |
348 // default: do nothing. | |
349 } | |
350 | |
351 @Override | |
352 public String toString() { | |
353 StringBuilder builder = new StringBuilder(); | |
354 builder.append(getClass().getSimpleName()); | |
355 builder.append(" #"); | |
356 builder.append(id()); | |
357 if (this instanceof Instruction) { | |
358 builder.append(" @ "); | |
359 builder.append(((Instruction) this).bci()); | |
360 } | |
361 builder.append(" [").append(flagsToString()).append("]"); | |
362 return builder.toString(); | |
363 } | |
364 | |
365 public String flagsToString() { | |
366 StringBuilder sb = new StringBuilder(); | |
367 for (Flag f : Flag.values()) { | |
368 if (checkFlag(f)) { | |
369 if (sb.length() != 0) { | |
370 sb.append(' '); | |
371 } | |
372 sb.append(f.name()); | |
373 } | |
374 } | |
375 return sb.toString(); | |
376 } | |
377 | |
378 public final boolean isDeadPhi() { | |
379 return checkFlag(Flag.PhiDead); | |
380 } | |
381 | |
382 /** | |
383 * This method supports the visitor pattern by accepting a visitor and calling the | |
384 * appropriate {@code visit()} method. | |
385 * | |
386 * @param v the visitor to accept | |
387 */ | |
388 public abstract void accept(ValueVisitor v); | |
389 | |
390 public abstract void print(LogStream out); | |
391 | |
392 /** | |
393 * This method returns a unique identification number for this value. The number returned is unique | |
394 * only to the compilation that produced this node and is computed lazily by using the current compilation | |
395 * for the current thread. Thus the first access is a hash lookup using {@link java.lang.ThreadLocal} and | |
396 * should not be considered fast. Because of the potentially slow first access, use of this ID should be | |
397 * restricted to debugging output. | |
398 * @return a unique ID for this value | |
399 */ | |
400 public int id() { | |
401 if (id == 0) { | |
402 C1XMetrics.UniqueValueIdsAssigned++; | |
403 id = C1XCompilation.compilation().nextID(); | |
404 } | |
405 return id; | |
406 } | |
407 } |