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comparison graal/com.oracle.max.graal.compiler/src/com/sun/c1x/alloc/IntervalWalker.java @ 2872:0341b6424579

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Project renaming.
author Thomas Wuerthinger <thomas@wuerthinger.net>
date Wed, 08 Jun 2011 08:42:25 +0200
parents graal/GraalCompiler/src/com/sun/c1x/alloc/IntervalWalker.java@16b9a8b5ad39
children
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2871:d704eb526603 2872:0341b6424579
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.alloc;
24
25 import com.sun.c1x.*;
26 import com.sun.c1x.alloc.Interval.*;
27 import com.sun.c1x.debug.*;
28
29 /**
30 *
31 * @author Thomas Wuerthinger
32 */
33 public class IntervalWalker {
34
35 protected final C1XCompilation compilation;
36 protected final LinearScan allocator;
37
38 /**
39 * Sorted list of intervals, not live before the current position.
40 */
41 RegisterBindingLists unhandledLists;
42
43 /**
44 * Sorted list of intervals, live at the current position.
45 */
46 RegisterBindingLists activeLists;
47
48 /**
49 * Sorted list of intervals in a life time hole at the current position.
50 */
51 RegisterBindingLists inactiveLists;
52
53 /**
54 * The current interval (taken from the unhandled list) being processed.
55 */
56 protected Interval current;
57
58 /**
59 * The current position (intercept point through the intervals).
60 */
61 protected int currentPosition;
62
63 /**
64 * The binding of the current interval being processed.
65 */
66 protected RegisterBinding currentBinding;
67
68 /**
69 * Processes the {@linkplain #current} interval in an attempt to allocate a physical
70 * register to it and thus allow it to be moved to a list of {@linkplain #activeLists active} intervals.
71 *
72 * @return {@code true} if a register was allocated to the {@linkplain #current} interval
73 */
74 boolean activateCurrent() {
75 return true;
76 }
77
78 void walkBefore(int lirOpId) {
79 walkTo(lirOpId - 1);
80 }
81
82 void walk() {
83 walkTo(Integer.MAX_VALUE);
84 }
85
86 /**
87 * Creates a new interval walker.
88 *
89 * @param allocator the register allocator context
90 * @param unhandledFixed the list of unhandled {@linkplain RegisterBinding#Fixed fixed} intervals
91 * @param unhandledAny the list of unhandled {@linkplain RegisterBinding#Any non-fixed} intervals
92 */
93 IntervalWalker(LinearScan allocator, Interval unhandledFixed, Interval unhandledAny) {
94 this.compilation = allocator.compilation;
95 this.allocator = allocator;
96
97 unhandledLists = new RegisterBindingLists(unhandledFixed, unhandledAny);
98 activeLists = new RegisterBindingLists(Interval.EndMarker, Interval.EndMarker);
99 inactiveLists = new RegisterBindingLists(Interval.EndMarker, Interval.EndMarker);
100 currentPosition = -1;
101 current = null;
102 nextInterval();
103 }
104
105 void removeFromList(Interval interval) {
106 if (interval.state == State.Active) {
107 activeLists.remove(RegisterBinding.Any, interval);
108 } else {
109 assert interval.state == State.Inactive : "invalid state";
110 inactiveLists.remove(RegisterBinding.Any, interval);
111 }
112 }
113
114 void walkTo(State state, int from) {
115 assert state == State.Active || state == State.Inactive : "wrong state";
116 for (RegisterBinding binding : RegisterBinding.VALUES) {
117 Interval prevprev = null;
118 Interval prev = (state == State.Active) ? activeLists.get(binding) : inactiveLists.get(binding);
119 Interval next = prev;
120 while (next.currentFrom() <= from) {
121 Interval cur = next;
122 next = cur.next;
123
124 boolean rangeHasChanged = false;
125 while (cur.currentTo() <= from) {
126 cur.nextRange();
127 rangeHasChanged = true;
128 }
129
130 // also handle move from inactive list to active list
131 rangeHasChanged = rangeHasChanged || (state == State.Inactive && cur.currentFrom() <= from);
132
133 if (rangeHasChanged) {
134 // remove cur from list
135 if (prevprev == null) {
136 if (state == State.Active) {
137 activeLists.set(binding, next);
138 } else {
139 inactiveLists.set(binding, next);
140 }
141 } else {
142 prevprev.next = next;
143 }
144 prev = next;
145 if (cur.currentAtEnd()) {
146 // move to handled state (not maintained as a list)
147 cur.state = State.Handled;
148 intervalMoved(cur, binding, state, State.Handled);
149 } else if (cur.currentFrom() <= from) {
150 // sort into active list
151 activeLists.addToListSortedByCurrentFromPositions(binding, cur);
152 cur.state = State.Active;
153 if (prev == cur) {
154 assert state == State.Active : "check";
155 prevprev = prev;
156 prev = cur.next;
157 }
158 intervalMoved(cur, binding, state, State.Active);
159 } else {
160 // sort into inactive list
161 inactiveLists.addToListSortedByCurrentFromPositions(binding, cur);
162 cur.state = State.Inactive;
163 if (prev == cur) {
164 assert state == State.Inactive : "check";
165 prevprev = prev;
166 prev = cur.next;
167 }
168 intervalMoved(cur, binding, state, State.Inactive);
169 }
170 } else {
171 prevprev = prev;
172 prev = cur.next;
173 }
174 }
175 }
176 }
177
178 void nextInterval() {
179 RegisterBinding binding;
180 Interval any = unhandledLists.any;
181 Interval fixed = unhandledLists.fixed;
182
183 if (any != Interval.EndMarker) {
184 // intervals may start at same position . prefer fixed interval
185 binding = fixed != Interval.EndMarker && fixed.from() <= any.from() ? RegisterBinding.Fixed : RegisterBinding.Any;
186
187 assert binding == RegisterBinding.Fixed && fixed.from() <= any.from() || binding == RegisterBinding.Any && any.from() <= fixed.from() : "wrong interval!!!";
188 assert any == Interval.EndMarker || fixed == Interval.EndMarker || any.from() != fixed.from() || binding == RegisterBinding.Fixed : "if fixed and any-Interval start at same position, fixed must be processed first";
189
190 } else if (fixed != Interval.EndMarker) {
191 binding = RegisterBinding.Fixed;
192 } else {
193 current = null;
194 return;
195 }
196 currentBinding = binding;
197 current = unhandledLists.get(binding);
198 unhandledLists.set(binding, current.next);
199 current.next = Interval.EndMarker;
200 current.rewindRange();
201 }
202
203 void walkTo(int toOpId) {
204 assert currentPosition <= toOpId : "can not walk backwards";
205 while (current != null) {
206 boolean isActive = current.from() <= toOpId;
207 int opId = isActive ? current.from() : toOpId;
208
209 if (C1XOptions.TraceLinearScanLevel >= 2 && !TTY.isSuppressed()) {
210 if (currentPosition < opId) {
211 TTY.println();
212 TTY.println("walkTo(%d) *", opId);
213 }
214 }
215
216 // set currentPosition prior to call of walkTo
217 currentPosition = opId;
218
219 // call walkTo even if currentPosition == id
220 walkTo(State.Active, opId);
221 walkTo(State.Inactive, opId);
222
223 if (isActive) {
224 current.state = State.Active;
225 if (activateCurrent()) {
226 activeLists.addToListSortedByCurrentFromPositions(currentBinding, current);
227 intervalMoved(current, currentBinding, State.Unhandled, State.Active);
228 }
229
230 nextInterval();
231 } else {
232 return;
233 }
234 }
235 }
236
237 private void intervalMoved(Interval interval, RegisterBinding kind, State from, State to) {
238 // intervalMoved() is called whenever an interval moves from one interval list to another.
239 // In the implementation of this method it is prohibited to move the interval to any list.
240 if (C1XOptions.TraceLinearScanLevel >= 4 && !TTY.isSuppressed()) {
241 TTY.print(from.toString() + " to " + to.toString());
242 TTY.fillTo(23);
243 TTY.out().println(interval.logString(allocator));
244 }
245 }
246 }