1 /*
2 * Copyright (c) 2009, 2012, 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 org.graalvm.compiler.lir;
24
25 import java.util.ArrayList;
26 import java.util.Arrays;
27 import java.util.List;
28
29 import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
30 import org.graalvm.compiler.core.common.cfg.AbstractControlFlowGraph;
31 import org.graalvm.compiler.core.common.cfg.BlockMap;
32 import org.graalvm.compiler.lir.StandardOp.BlockEndOp;
33 import org.graalvm.compiler.lir.StandardOp.LabelOp;
34 import org.graalvm.compiler.lir.gen.LIRGenerator;
35
36 /**
37 * This class implements the overall container for the LIR graph and directs its construction,
38 * optimization, and finalization.
39 */
40 public final class LIR extends LIRGenerator.VariableProvider {
41
42 private final AbstractControlFlowGraph<?> cfg;
43
44 /**
45 * The linear-scan ordered list of blocks.
46 */
47 private final AbstractBlockBase<?>[] linearScanOrder;
48
49 /**
50 * The order in which the code is emitted.
51 */
52 private final AbstractBlockBase<?>[] codeEmittingOrder;
53
54 /**
55 * Map from {@linkplain AbstractBlockBase block} to {@linkplain LIRInstruction}s. Note that we
56 * are using {@link ArrayList} instead of {@link List} to avoid interface dispatch.
57 */
58 private final BlockMap<ArrayList<LIRInstruction>> lirInstructions;
59
60 private boolean hasArgInCallerFrame;
61
62 /**
63 * Creates a new LIR instance for the specified compilation.
64 */
65 public LIR(AbstractControlFlowGraph<?> cfg, AbstractBlockBase<?>[] linearScanOrder, AbstractBlockBase<?>[] codeEmittingOrder) {
66 this.cfg = cfg;
67 this.codeEmittingOrder = codeEmittingOrder;
68 this.linearScanOrder = linearScanOrder;
69 this.lirInstructions = new BlockMap<>(cfg);
70 }
71
72 public AbstractControlFlowGraph<?> getControlFlowGraph() {
73 return cfg;
74 }
75
76 /**
77 * Determines if any instruction in the LIR has debug info associated with it.
78 */
79 public boolean hasDebugInfo() {
80 for (AbstractBlockBase<?> b : linearScanOrder()) {
81 for (LIRInstruction op : getLIRforBlock(b)) {
82 if (op.hasState()) {
83 return true;
84 }
85 }
86 }
87 return false;
88 }
89
90 public ArrayList<LIRInstruction> getLIRforBlock(AbstractBlockBase<?> block) {
91 return lirInstructions.get(block);
92 }
93
94 public void setLIRforBlock(AbstractBlockBase<?> block, ArrayList<LIRInstruction> list) {
95 assert getLIRforBlock(block) == null : "lir instruction list should only be initialized once";
96 lirInstructions.put(block, list);
97 }
98
99 /**
100 * Gets the linear scan ordering of blocks as an array.
101 *
102 * @return the blocks in linear scan order
103 */
104 public AbstractBlockBase<?>[] linearScanOrder() {
105 return linearScanOrder;
106 }
107
108 public AbstractBlockBase<?>[] codeEmittingOrder() {
109 return codeEmittingOrder;
110 }
111
112 public void setHasArgInCallerFrame() {
113 hasArgInCallerFrame = true;
114 }
115
116 /**
117 * Determines if any of the parameters to the method are passed via the stack where the
118 * parameters are located in the caller's frame.
119 */
120 public boolean hasArgInCallerFrame() {
121 return hasArgInCallerFrame;
122 }
123
124 /**
125 * Gets the next non-{@code null} block in a list.
126 *
127 * @param blocks list of blocks
128 * @param blockIndex index of the current block
129 * @return the next block in the list that is none {@code null} or {@code null} if there is no
130 * such block
131 */
132 public static AbstractBlockBase<?> getNextBlock(AbstractBlockBase<?>[] blocks, int blockIndex) {
133 for (int nextIndex = blockIndex + 1; nextIndex > 0 && nextIndex < blocks.length; nextIndex++) {
134 AbstractBlockBase<?> nextBlock = blocks[nextIndex];
135 if (nextBlock != null) {
136 return nextBlock;
137 }
138 }
139 return null;
140 }
141
142 /**
143 * Gets the exception edge (if any) originating at a given operation.
144 */
145 public static LabelRef getExceptionEdge(LIRInstruction op) {
146 final LabelRef[] exceptionEdge = {null};
147 op.forEachState(state -> {
148 if (state.exceptionEdge != null) {
149 assert exceptionEdge[0] == null;
150 exceptionEdge[0] = state.exceptionEdge;
151 }
152 });
153 return exceptionEdge[0];
154 }
155
156 /**
157 * The maximum distance an operation with an {@linkplain #getExceptionEdge(LIRInstruction)
158 * exception edge} can be from the last instruction of a LIR block. The value of 3 is based on a
159 * non-void call operation that has an exception edge. Such a call may move the result to
160 * another register and then spill it.
161 * <p>
162 * The rationale for such a constant is to limit the search for an insertion point when adding
163 * move operations at the end of a block. Such moves must be inserted before all control flow
164 * instructions.
165 */
166 public static final int MAX_EXCEPTION_EDGE_OP_DISTANCE_FROM_END = 3;
167
168 public static boolean verifyBlock(LIR lir, AbstractBlockBase<?> block) {
169 ArrayList<LIRInstruction> ops = lir.getLIRforBlock(block);
170 if (ops.size() == 0) {
171 return false;
172 }
173 assert ops.get(0) instanceof LabelOp : String.format("Not a Label %s (Block %s)", ops.get(0).getClass(), block);
174 LIRInstruction opWithExceptionEdge = null;
175 int index = 0;
176 int lastIndex = ops.size() - 1;
177 for (LIRInstruction op : ops.subList(0, lastIndex)) {
178 assert !(op instanceof BlockEndOp) : String.format("BlockEndOp %s (Block %s)", op.getClass(), block);
179 LabelRef exceptionEdge = getExceptionEdge(op);
180 if (exceptionEdge != null) {
181 assert opWithExceptionEdge == null : "multiple ops with an exception edge not allowed";
182 opWithExceptionEdge = op;
183 int distanceFromEnd = lastIndex - index;
184 assert distanceFromEnd <= MAX_EXCEPTION_EDGE_OP_DISTANCE_FROM_END;
185 }
186 index++;
187 }
188 LIRInstruction end = ops.get(lastIndex);
189 assert end instanceof BlockEndOp : String.format("Not a BlockEndOp %s (Block %s)", end.getClass(), block);
190 return true;
191 }
192
193 public static boolean verifyBlocks(LIR lir, AbstractBlockBase<?>[] blocks) {
194 for (AbstractBlockBase<?> block : blocks) {
195 if (block == null) {
196 continue;
197 }
198 for (AbstractBlockBase<?> sux : block.getSuccessors()) {
199 assert Arrays.asList(blocks).contains(sux) : "missing successor from: " + block + "to: " + sux;
200 }
201 for (AbstractBlockBase<?> pred : block.getPredecessors()) {
202 assert Arrays.asList(blocks).contains(pred) : "missing predecessor from: " + block + "to: " + pred;
203 }
204 if (!verifyBlock(lir, block)) {
205 return false;
206 }
207 }
208 return true;
209 }
210
211 public void resetLabels() {
212
213 for (AbstractBlockBase<?> block : codeEmittingOrder()) {
214 if (block == null) {
215 continue;
216 }
217 for (LIRInstruction inst : lirInstructions.get(block)) {
218 if (inst instanceof LabelOp) {
219 ((LabelOp) inst).getLabel().reset();
220 }
221 }
222 }
223 }
224
225 }