1 /*
2 * Copyright (c) 2013, 2016, 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.aarch64;
24
25 import static jdk.vm.ci.code.ValueUtil.asAllocatableValue;
26 import static jdk.vm.ci.code.ValueUtil.asRegister;
27
28 import java.util.function.Function;
29
30 import org.graalvm.compiler.asm.Label;
31 import org.graalvm.compiler.asm.NumUtil;
32 import org.graalvm.compiler.asm.aarch64.AArch64Address;
33 import org.graalvm.compiler.asm.aarch64.AArch64Assembler;
34 import org.graalvm.compiler.asm.aarch64.AArch64Assembler.ConditionFlag;
35 import org.graalvm.compiler.asm.aarch64.AArch64MacroAssembler;
36 import org.graalvm.compiler.asm.aarch64.AArch64MacroAssembler.PatchLabelKind;
37 import org.graalvm.compiler.code.CompilationResult.JumpTable;
38 import org.graalvm.compiler.core.common.LIRKind;
39 import org.graalvm.compiler.core.common.calc.Condition;
40 import org.graalvm.compiler.debug.GraalError;
41 import org.graalvm.compiler.lir.ConstantValue;
42 import org.graalvm.compiler.lir.LIRInstructionClass;
43 import org.graalvm.compiler.lir.LabelRef;
44 import org.graalvm.compiler.lir.Opcode;
45 import org.graalvm.compiler.lir.StandardOp;
46 import org.graalvm.compiler.lir.SwitchStrategy;
47 import org.graalvm.compiler.lir.SwitchStrategy.BaseSwitchClosure;
48 import org.graalvm.compiler.lir.Variable;
49 import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
50
51 import jdk.vm.ci.aarch64.AArch64Kind;
52 import jdk.vm.ci.code.Register;
53 import jdk.vm.ci.meta.Constant;
54 import jdk.vm.ci.meta.JavaConstant;
55 import jdk.vm.ci.meta.Value;
56
57 public class AArch64ControlFlow {
58
59 /**
60 * Compares integer register to 0 and branches if condition is true. Condition may only be equal
61 * or non-equal.
62 */
63 // TODO (das) where do we need this?
64 // public static class CompareAndBranchOp extends AArch64LIRInstruction implements
65 // StandardOp.BranchOp {
66 // private final ConditionFlag condition;
67 // private final LabelRef destination;
68 // @Use({REG}) private Value x;
69 //
70 // public CompareAndBranchOp(Condition condition, LabelRef destination, Value x) {
71 // assert condition == Condition.EQ || condition == Condition.NE;
72 // assert ARMv8.isGpKind(x.getKind());
73 // this.condition = condition == Condition.EQ ? ConditionFlag.EQ : ConditionFlag.NE;
74 // this.destination = destination;
75 // this.x = x;
76 // }
77 //
78 // @Override
79 // public void emitCode(CompilationResultBuilder crb, ARMv8MacroAssembler masm) {
80 // int size = ARMv8.bitsize(x.getKind());
81 // if (condition == ConditionFlag.EQ) {
82 // masm.cbz(size, asRegister(x), destination.label());
83 // } else {
84 // masm.cbnz(size, asRegister(x), destination.label());
85 // }
86 // }
87 // }
88
89 public static class BranchOp extends AArch64BlockEndOp implements StandardOp.BranchOp {
90 public static final LIRInstructionClass<BranchOp> TYPE = LIRInstructionClass.create(BranchOp.class);
91
92 private final AArch64Assembler.ConditionFlag condition;
93 private final LabelRef trueDestination;
94 private final LabelRef falseDestination;
95
96 private final double trueDestinationProbability;
97
98 public BranchOp(AArch64Assembler.ConditionFlag condition, LabelRef trueDestination, LabelRef falseDestination, double trueDestinationProbability) {
99 super(TYPE);
100 this.condition = condition;
101 this.trueDestination = trueDestination;
102 this.falseDestination = falseDestination;
103 this.trueDestinationProbability = trueDestinationProbability;
104 }
105
106 @Override
107 public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
108 /*
109 * Explanation: Depending on what the successor edge is, we can use the fall-through to
110 * optimize the generated code. If neither is a successor edge, use the branch
111 * probability to try to take the conditional jump as often as possible to avoid
112 * executing two instructions instead of one.
113 */
114 if (crb.isSuccessorEdge(trueDestination)) {
115 masm.branchConditionally(condition.negate(), falseDestination.label());
116 } else if (crb.isSuccessorEdge(falseDestination)) {
117 masm.branchConditionally(condition, trueDestination.label());
118 } else if (trueDestinationProbability < 0.5) {
119 masm.branchConditionally(condition.negate(), falseDestination.label());
120 masm.jmp(trueDestination.label());
121 } else {
122 masm.branchConditionally(condition, trueDestination.label());
123 masm.jmp(falseDestination.label());
124 }
125 }
126
127 }
128
129 @Opcode("CMOVE")
130 public static class CondMoveOp extends AArch64LIRInstruction {
131 public static final LIRInstructionClass<CondMoveOp> TYPE = LIRInstructionClass.create(CondMoveOp.class);
132
133 @Def protected Value result;
134 @Use protected Value trueValue;
135 @Use protected Value falseValue;
136 private final AArch64Assembler.ConditionFlag condition;
137
138 public CondMoveOp(Variable result, AArch64Assembler.ConditionFlag condition, Value trueValue, Value falseValue) {
139 super(TYPE);
140 assert trueValue.getPlatformKind() == falseValue.getPlatformKind() && trueValue.getPlatformKind() == result.getPlatformKind();
141 this.result = result;
142 this.condition = condition;
143 this.trueValue = trueValue;
144 this.falseValue = falseValue;
145 }
146
147 @Override
148 public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
149 AArch64Kind kind = (AArch64Kind) trueValue.getPlatformKind();
150 int size = kind.getSizeInBytes() * Byte.SIZE;
151 if (kind.isInteger()) {
152 masm.cmov(size, asRegister(result), asRegister(trueValue), asRegister(falseValue), condition);
153 } else {
154 masm.fcmov(size, asRegister(result), asRegister(trueValue), asRegister(falseValue), condition);
155 }
156 }
157 }
158
159 public static class StrategySwitchOp extends AArch64BlockEndOp implements StandardOp.BlockEndOp {
160 public static final LIRInstructionClass<StrategySwitchOp> TYPE = LIRInstructionClass.create(StrategySwitchOp.class);
161
162 private final Constant[] keyConstants;
163 protected final SwitchStrategy strategy;
164 private final Function<Condition, ConditionFlag> converter;
165 private final LabelRef[] keyTargets;
166 private final LabelRef defaultTarget;
167 @Alive protected Value key;
168 // TODO (das) This could be optimized: We only need the scratch register in case of a
169 // datapatch, or too large immediates.
170 @Temp protected Value scratch;
171
172 public StrategySwitchOp(SwitchStrategy strategy, LabelRef[] keyTargets, LabelRef defaultTarget, Value key, Value scratch,
173 Function<Condition, ConditionFlag> converter) {
174 this(TYPE, strategy, keyTargets, defaultTarget, key, scratch, converter);
175 }
176
177 protected StrategySwitchOp(LIRInstructionClass<? extends StrategySwitchOp> c, SwitchStrategy strategy, LabelRef[] keyTargets, LabelRef defaultTarget, Value key, Value scratch,
178 Function<Condition, ConditionFlag> converter) {
179 super(c);
180 this.strategy = strategy;
181 this.converter = converter;
182 this.keyConstants = strategy.getKeyConstants();
183 this.keyTargets = keyTargets;
184 this.defaultTarget = defaultTarget;
185 this.key = key;
186 this.scratch = scratch;
187 assert keyConstants.length == keyTargets.length;
188 assert keyConstants.length == strategy.keyProbabilities.length;
189 }
190
191 @Override
192 public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
193 strategy.run(new SwitchClosure(asRegister(key), crb, masm));
194 }
195
196 public class SwitchClosure extends BaseSwitchClosure {
197
198 protected final Register keyRegister;
199 protected final CompilationResultBuilder crb;
200 protected final AArch64MacroAssembler masm;
201
202 protected SwitchClosure(Register keyRegister, CompilationResultBuilder crb, AArch64MacroAssembler masm) {
203 super(crb, masm, keyTargets, defaultTarget);
204 this.keyRegister = keyRegister;
205 this.crb = crb;
206 this.masm = masm;
207 }
208
209 protected void emitComparison(Constant c) {
210 JavaConstant jc = (JavaConstant) c;
211 ConstantValue constVal = new ConstantValue(LIRKind.value(key.getPlatformKind()), c);
212 switch (jc.getJavaKind()) {
213 case Int:
214 long lc = jc.asLong();
215 assert NumUtil.isInt(lc);
216 emitCompare(crb, masm, key, scratch, constVal);
217 break;
218 case Long:
219 emitCompare(crb, masm, key, scratch, constVal);
220 break;
221 case Object:
222 emitCompare(crb, masm, key, scratch, constVal);
223 break;
224 default:
225 throw new GraalError("switch only supported for int, long and object");
226 }
227 }
228
229 @Override
230 protected void conditionalJump(int index, Condition condition, Label target) {
231 emitComparison(keyConstants[index]);
232 masm.branchConditionally(converter.apply(condition), target);
233 }
234 }
235 }
236
237 public static class TableSwitchOp extends AArch64BlockEndOp implements StandardOp.BlockEndOp {
238 public static final LIRInstructionClass<TableSwitchOp> TYPE = LIRInstructionClass.create(TableSwitchOp.class);
239
240 private final int lowKey;
241 private final LabelRef defaultTarget;
242 private final LabelRef[] targets;
243 @Alive protected Variable keyValue;
244 @Temp protected Variable scratchValue;
245
246 public TableSwitchOp(int lowKey, LabelRef defaultTarget, LabelRef[] targets, Variable key, Variable scratch) {
247 super(TYPE);
248 this.lowKey = lowKey;
249 this.defaultTarget = defaultTarget;
250 this.targets = targets;
251 this.keyValue = key;
252 this.scratchValue = scratch;
253 }
254
255 @Override
256 public void emitCode(CompilationResultBuilder crb, AArch64MacroAssembler masm) {
257 Register key = asRegister(keyValue);
258 Register scratch = asRegister(scratchValue);
259 if (lowKey != 0) {
260 if (AArch64MacroAssembler.isArithmeticImmediate(lowKey)) {
261 masm.sub(32, key, key, lowKey);
262 } else {
263 ConstantValue constVal = new ConstantValue(LIRKind.value(AArch64Kind.WORD), JavaConstant.forInt(lowKey));
264 AArch64Move.move(crb, masm, scratchValue, constVal);
265 masm.sub(32, key, key, scratch);
266 }
267 }
268 if (defaultTarget != null) {
269 // if key is not in table range, jump to default target if it exists.
270 ConstantValue constVal = new ConstantValue(LIRKind.value(AArch64Kind.WORD), JavaConstant.forInt(targets.length));
271 emitCompare(crb, masm, keyValue, scratchValue, constVal);
272 masm.branchConditionally(AArch64Assembler.ConditionFlag.HS, defaultTarget.label());
273 }
274
275 // Load the start address of the jump table - which starts 3 instructions after the adr
276 // - into scratch.
277 masm.adr(scratch, 4 * 3);
278 masm.ldr(32, scratch, AArch64Address.createRegisterOffsetAddress(scratch, key, /* scaled */true));
279 masm.jmp(scratch);
280 int jumpTablePos = masm.position();
281 // emit jump table entries
282 for (LabelRef target : targets) {
283 Label label = target.label();
284 if (label.isBound()) {
285 masm.emitInt(target.label().position());
286 } else {
287 label.addPatchAt(masm.position());
288 masm.emitInt(PatchLabelKind.JUMP_ADDRESS.encoding);
289 }
290 }
291 JumpTable jt = new JumpTable(jumpTablePos, lowKey, lowKey + targets.length - 1, 4);
292 crb.compilationResult.addAnnotation(jt);
293 }
294 }
295
296 private static void emitCompare(CompilationResultBuilder crb, AArch64MacroAssembler masm, Value key, Value scratchValue, ConstantValue c) {
297 long imm = c.getJavaConstant().asLong();
298 final int size = key.getPlatformKind().getSizeInBytes() * Byte.SIZE;
299 if (AArch64MacroAssembler.isComparisonImmediate(imm)) {
300 masm.cmp(size, asRegister(key), (int) imm);
301 } else {
302 AArch64Move.move(crb, masm, asAllocatableValue(scratchValue), c);
303 masm.cmp(size, asRegister(key), asRegister(scratchValue));
304 }
305 }
306
307 }