1 /*
2 * Copyright (c) 2009, 2018, 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
24
25 package org.graalvm.compiler.lir;
26
27 import java.util.ArrayList;
28 import java.util.Arrays;
29 import java.util.List;
30
31 import org.graalvm.compiler.asm.Label;
32 import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
33 import org.graalvm.compiler.core.common.cfg.AbstractControlFlowGraph;
34 import org.graalvm.compiler.core.common.cfg.BlockMap;
35 import org.graalvm.compiler.debug.DebugContext;
36 import org.graalvm.compiler.lir.StandardOp.BlockEndOp;
37 import org.graalvm.compiler.lir.StandardOp.LabelOp;
38 import org.graalvm.compiler.lir.StandardOp.LabelHoldingOp;
39 import org.graalvm.compiler.lir.gen.LIRGenerator;
40 import org.graalvm.compiler.options.OptionValues;
41
42 /**
43 * This class implements the overall container for the LIR graph and directs its construction,
44 * optimization, and finalization.
45 */
46 public final class LIR extends LIRGenerator.VariableProvider {
47
48 private final AbstractControlFlowGraph<?> cfg;
49
50 /**
51 * The linear-scan ordered list of blocks.
52 */
53 private final AbstractBlockBase<?>[] linearScanOrder;
54
55 /**
56 * The order in which the code is emitted.
57 */
58 private final AbstractBlockBase<?>[] codeEmittingOrder;
59
60 /**
61 * Map from {@linkplain AbstractBlockBase block} to {@linkplain LIRInstruction}s. Note that we
62 * are using {@link ArrayList} instead of {@link List} to avoid interface dispatch.
63 */
64 private final BlockMap<ArrayList<LIRInstruction>> lirInstructions;
65
66 private boolean hasArgInCallerFrame;
67
68 private final OptionValues options;
69
70 private final DebugContext debug;
71
72 /**
73 * Creates a new LIR instance for the specified compilation.
74 */
75 public LIR(AbstractControlFlowGraph<?> cfg, AbstractBlockBase<?>[] linearScanOrder, AbstractBlockBase<?>[] codeEmittingOrder, OptionValues options, DebugContext debug) {
76 this.cfg = cfg;
77 this.codeEmittingOrder = codeEmittingOrder;
78 this.linearScanOrder = linearScanOrder;
79 this.lirInstructions = new BlockMap<>(cfg);
80 this.options = options;
81 this.debug = debug;
82 }
83
84 public AbstractControlFlowGraph<?> getControlFlowGraph() {
85 return cfg;
86 }
87
88 public OptionValues getOptions() {
89 return options;
90 }
91
92 public DebugContext getDebug() {
93 return debug;
94 }
95
96 /**
97 * Determines if any instruction in the LIR has debug info associated with it.
98 */
99 public boolean hasDebugInfo() {
100 for (AbstractBlockBase<?> b : linearScanOrder()) {
101 for (LIRInstruction op : getLIRforBlock(b)) {
102 if (op.hasState()) {
103 return true;
104 }
105 }
106 }
107 return false;
108 }
109
110 public ArrayList<LIRInstruction> getLIRforBlock(AbstractBlockBase<?> block) {
111 return lirInstructions.get(block);
112 }
113
114 public void setLIRforBlock(AbstractBlockBase<?> block, ArrayList<LIRInstruction> list) {
115 assert getLIRforBlock(block) == null : "lir instruction list should only be initialized once";
116 lirInstructions.put(block, list);
117 }
118
119 /**
120 * Gets the linear scan ordering of blocks as an array.
121 *
122 * @return the blocks in linear scan order
123 */
124 public AbstractBlockBase<?>[] linearScanOrder() {
125 return linearScanOrder;
126 }
127
128 public AbstractBlockBase<?>[] codeEmittingOrder() {
129 return codeEmittingOrder;
130 }
131
132 public void setHasArgInCallerFrame() {
133 hasArgInCallerFrame = true;
134 }
135
136 /**
137 * Determines if any of the parameters to the method are passed via the stack where the
138 * parameters are located in the caller's frame.
139 */
140 public boolean hasArgInCallerFrame() {
141 return hasArgInCallerFrame;
142 }
143
144 /**
145 * Gets the next non-{@code null} block in a list.
146 *
147 * @param blocks list of blocks
148 * @param blockIndex index of the current block
149 * @return the next block in the list that is none {@code null} or {@code null} if there is no
150 * such block
151 */
152 public static AbstractBlockBase<?> getNextBlock(AbstractBlockBase<?>[] blocks, int blockIndex) {
153 for (int nextIndex = blockIndex + 1; nextIndex > 0 && nextIndex < blocks.length; nextIndex++) {
154 AbstractBlockBase<?> nextBlock = blocks[nextIndex];
155 if (nextBlock != null) {
156 return nextBlock;
157 }
158 }
159 return null;
160 }
161
162 /**
163 * Gets the exception edge (if any) originating at a given operation.
164 */
165 public static LabelRef getExceptionEdge(LIRInstruction op) {
166 final LabelRef[] exceptionEdge = {null};
167 op.forEachState(state -> {
168 if (state.exceptionEdge != null) {
169 assert exceptionEdge[0] == null;
170 exceptionEdge[0] = state.exceptionEdge;
171 }
172 });
173 return exceptionEdge[0];
174 }
175
176 /**
177 * The maximum distance an operation with an {@linkplain #getExceptionEdge(LIRInstruction)
178 * exception edge} can be from the last instruction of a LIR block. The value of 3 is based on a
179 * non-void call operation that has an exception edge. Such a call may move the result to
180 * another register and then spill it.
181 * <p>
182 * The rationale for such a constant is to limit the search for an insertion point when adding
183 * move operations at the end of a block. Such moves must be inserted before all control flow
184 * instructions.
185 */
186 public static final int MAX_EXCEPTION_EDGE_OP_DISTANCE_FROM_END = 3;
187
188 public static boolean verifyBlock(LIR lir, AbstractBlockBase<?> block) {
189 ArrayList<LIRInstruction> ops = lir.getLIRforBlock(block);
190 if (ops.size() == 0) {
191 return false;
192 }
193 assert ops.get(0) instanceof LabelOp : String.format("Not a Label %s (Block %s)", ops.get(0).getClass(), block);
194 LIRInstruction opWithExceptionEdge = null;
195 int index = 0;
196 int lastIndex = ops.size() - 1;
197 for (LIRInstruction op : ops.subList(0, lastIndex)) {
198 assert !(op instanceof BlockEndOp) : String.format("BlockEndOp %s (Block %s)", op.getClass(), block);
199 LabelRef exceptionEdge = getExceptionEdge(op);
200 if (exceptionEdge != null) {
201 assert opWithExceptionEdge == null : "multiple ops with an exception edge not allowed";
202 opWithExceptionEdge = op;
203 int distanceFromEnd = lastIndex - index;
204 assert distanceFromEnd <= MAX_EXCEPTION_EDGE_OP_DISTANCE_FROM_END;
205 }
206 index++;
207 }
208 LIRInstruction end = ops.get(lastIndex);
209 assert end instanceof BlockEndOp : String.format("Not a BlockEndOp %s (Block %s)", end.getClass(), block);
210 return true;
211 }
212
213 public static boolean verifyBlocks(LIR lir, AbstractBlockBase<?>[] blocks) {
214 for (AbstractBlockBase<?> block : blocks) {
215 if (block == null) {
216 continue;
217 }
218 for (AbstractBlockBase<?> sux : block.getSuccessors()) {
219 assert Arrays.asList(blocks).contains(sux) : "missing successor from: " + block + "to: " + sux;
220 }
221 for (AbstractBlockBase<?> pred : block.getPredecessors()) {
222 assert Arrays.asList(blocks).contains(pred) : "missing predecessor from: " + block + "to: " + pred;
223 }
224 if (!verifyBlock(lir, block)) {
225 return false;
226 }
227 }
228 return true;
229 }
230
231 public void resetLabels() {
232
233 for (AbstractBlockBase<?> block : codeEmittingOrder()) {
234 if (block == null) {
235 continue;
236 }
237 for (LIRInstruction inst : lirInstructions.get(block)) {
238 if (inst instanceof LabelHoldingOp) {
239 Label label = ((LabelHoldingOp) inst).getLabel();
240 if (label != null) {
241 label.reset();
242 }
243 }
244 }
245 }
246 }
247
248 }