1 /*
   2  * Copyright (c) 2009, 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.core.gen;
  24 
  25 import static jdk.vm.ci.code.ValueUtil.asRegister;
  26 import static jdk.vm.ci.code.ValueUtil.isLegal;
  27 import static jdk.vm.ci.code.ValueUtil.isRegister;
  28 import static org.graalvm.compiler.core.common.GraalOptions.MatchExpressions;
  29 import static org.graalvm.compiler.debug.GraalDebugConfig.Options.LogVerbose;
  30 import static org.graalvm.compiler.lir.LIR.verifyBlock;
  31 
  32 import java.util.ArrayList;
  33 import java.util.Collection;
  34 import java.util.List;
  35 import org.graalvm.compiler.core.common.LIRKind;
  36 import org.graalvm.compiler.core.common.calc.Condition;
  37 import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
  38 import org.graalvm.compiler.core.common.cfg.BlockMap;
  39 import org.graalvm.compiler.core.common.type.Stamp;
  40 import org.graalvm.compiler.core.match.ComplexMatchValue;
  41 import org.graalvm.compiler.core.match.MatchPattern;
  42 import org.graalvm.compiler.core.match.MatchRuleRegistry;
  43 import org.graalvm.compiler.core.match.MatchStatement;
  44 import org.graalvm.compiler.debug.Debug;
  45 import org.graalvm.compiler.debug.Debug.Scope;
  46 import org.graalvm.compiler.debug.GraalError;
  47 import org.graalvm.compiler.debug.TTY;
  48 import org.graalvm.compiler.graph.GraalGraphError;
  49 import org.graalvm.compiler.graph.Node;
  50 import org.graalvm.compiler.graph.NodeMap;
  51 import org.graalvm.compiler.graph.NodeSourcePosition;
  52 import org.graalvm.compiler.graph.iterators.NodeIterable;
  53 import org.graalvm.compiler.lir.FullInfopointOp;
  54 import org.graalvm.compiler.lir.LIRFrameState;
  55 import org.graalvm.compiler.lir.LIRInstruction;
  56 import org.graalvm.compiler.lir.LabelRef;
  57 import org.graalvm.compiler.lir.StandardOp.JumpOp;
  58 import org.graalvm.compiler.lir.StandardOp.LabelOp;
  59 import org.graalvm.compiler.lir.SwitchStrategy;
  60 import org.graalvm.compiler.lir.Variable;
  61 import org.graalvm.compiler.lir.debug.LIRGenerationDebugContext;
  62 import org.graalvm.compiler.lir.gen.LIRGenerator;
  63 import org.graalvm.compiler.lir.gen.LIRGenerator.Options;
  64 import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
  65 import org.graalvm.compiler.lir.gen.LIRGeneratorTool.BlockScope;
  66 import org.graalvm.compiler.nodes.AbstractBeginNode;
  67 import org.graalvm.compiler.nodes.AbstractEndNode;
  68 import org.graalvm.compiler.nodes.AbstractMergeNode;
  69 import org.graalvm.compiler.nodes.ConstantNode;
  70 import org.graalvm.compiler.nodes.DeoptimizingNode;
  71 import org.graalvm.compiler.nodes.DirectCallTargetNode;
  72 import org.graalvm.compiler.nodes.FixedNode;
  73 import org.graalvm.compiler.nodes.FrameState;
  74 import org.graalvm.compiler.nodes.FullInfopointNode;
  75 import org.graalvm.compiler.nodes.IfNode;
  76 import org.graalvm.compiler.nodes.IndirectCallTargetNode;
  77 import org.graalvm.compiler.nodes.Invoke;
  78 import org.graalvm.compiler.nodes.InvokeWithExceptionNode;
  79 import org.graalvm.compiler.nodes.LogicConstantNode;
  80 import org.graalvm.compiler.nodes.LogicNode;
  81 import org.graalvm.compiler.nodes.LoopEndNode;
  82 import org.graalvm.compiler.nodes.LoweredCallTargetNode;
  83 import org.graalvm.compiler.nodes.ParameterNode;
  84 import org.graalvm.compiler.nodes.PhiNode;
  85 import org.graalvm.compiler.nodes.StructuredGraph;
  86 import org.graalvm.compiler.nodes.ValueNode;
  87 import org.graalvm.compiler.nodes.ValuePhiNode;
  88 import org.graalvm.compiler.nodes.calc.CompareNode;
  89 import org.graalvm.compiler.nodes.calc.ConditionalNode;
  90 import org.graalvm.compiler.nodes.calc.IntegerTestNode;
  91 import org.graalvm.compiler.nodes.calc.IsNullNode;
  92 import org.graalvm.compiler.nodes.cfg.Block;
  93 import org.graalvm.compiler.nodes.cfg.ControlFlowGraph;
  94 import org.graalvm.compiler.nodes.extended.IntegerSwitchNode;
  95 import org.graalvm.compiler.nodes.extended.SwitchNode;
  96 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  97 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  98 import org.graalvm.compiler.nodes.spi.NodeValueMap;
  99 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
 100 import org.graalvm.compiler.options.OptionValues;
 101 import org.graalvm.util.EconomicMap;
 102 import org.graalvm.util.UnmodifiableMapCursor;
 103 
 104 import jdk.vm.ci.code.CallingConvention;
 105 import jdk.vm.ci.code.StackSlot;
 106 import jdk.vm.ci.code.ValueUtil;
 107 import jdk.vm.ci.meta.AllocatableValue;
 108 import jdk.vm.ci.meta.Constant;
 109 import jdk.vm.ci.meta.JavaConstant;
 110 import jdk.vm.ci.meta.JavaKind;
 111 import jdk.vm.ci.meta.PlatformKind;
 112 import jdk.vm.ci.meta.Value;
 113 
 114 /**
 115  * This class traverses the HIR instructions and generates LIR instructions from them.
 116  */
 117 public abstract class NodeLIRBuilder implements NodeLIRBuilderTool, LIRGenerationDebugContext {
 118 
 119     private final NodeMap<Value> nodeOperands;
 120     private final DebugInfoBuilder debugInfoBuilder;
 121     private final int traceLIRGeneratorLevel;
 122 
 123     protected final LIRGenerator gen;
 124 
 125     private ValueNode currentInstruction;
 126     private ValueNode lastInstructionPrinted; // Debugging only
 127 
 128     private final NodeMatchRules nodeMatchRules;
 129     private EconomicMap<Class<? extends Node>, List<MatchStatement>> matchRules;
 130 
 131     public NodeLIRBuilder(StructuredGraph graph, LIRGeneratorTool gen, NodeMatchRules nodeMatchRules) {
 132         this.gen = (LIRGenerator) gen;
 133         this.nodeMatchRules = nodeMatchRules;
 134         this.nodeOperands = graph.createNodeMap();
 135         this.debugInfoBuilder = createDebugInfoBuilder(graph, this);
 136         OptionValues options = graph.getOptions();
 137         if (MatchExpressions.getValue(options)) {
 138             matchRules = MatchRuleRegistry.lookup(nodeMatchRules.getClass(), options);
 139         }
 140         traceLIRGeneratorLevel = TTY.isSuppressed() ? 0 : Options.TraceLIRGeneratorLevel.getValue(options);
 141 
 142         assert nodeMatchRules.lirBuilder == null;
 143         nodeMatchRules.lirBuilder = this;
 144     }
 145 
 146     public NodeMatchRules getNodeMatchRules() {
 147         return nodeMatchRules;
 148     }
 149 
 150     @SuppressWarnings({"unused"})
 151     protected DebugInfoBuilder createDebugInfoBuilder(StructuredGraph graph, NodeValueMap nodeValueMap) {
 152         return new DebugInfoBuilder(nodeValueMap);
 153     }
 154 
 155     /**
 156      * Returns the operand that has been previously initialized by
 157      * {@link #setResult(ValueNode, Value)} with the result of an instruction. It's a code
 158      * generation error to ask for the operand of ValueNode that doesn't have one yet.
 159      *
 160      * @param node A node that produces a result value.
 161      */
 162     @Override
 163     public Value operand(Node node) {
 164         Value operand = getOperand(node);
 165         assert operand != null : String.format("missing operand for %1s", node);
 166         return operand;
 167     }
 168 
 169     @Override
 170     public boolean hasOperand(Node node) {
 171         return getOperand(node) != null;
 172     }
 173 
 174     private Value getOperand(Node node) {
 175         if (nodeOperands == null) {
 176             return null;
 177         }
 178         return nodeOperands.get(node);
 179     }
 180 
 181     @Override
 182     public ValueNode valueForOperand(Value value) {
 183         assert nodeOperands != null;
 184         UnmodifiableMapCursor<Node, Value> cursor = nodeOperands.getEntries();
 185         while (cursor.advance()) {
 186             if (cursor.getValue().equals(value)) {
 187                 return (ValueNode) cursor.getKey();
 188             }
 189         }
 190         return null;
 191     }
 192 
 193     @Override
 194     public Object getSourceForOperand(Value value) {
 195         return valueForOperand(value);
 196     }
 197 
 198     @Override
 199     public Value setResult(ValueNode x, Value operand) {
 200         assert (!isRegister(operand) || !gen.attributes(asRegister(operand)).isAllocatable());
 201         assert nodeOperands != null && (nodeOperands.get(x) == null || nodeOperands.get(x) instanceof ComplexMatchValue) : "operand cannot be set twice";
 202         assert operand != null && isLegal(operand) : "operand must be legal";
 203         assert !(x instanceof VirtualObjectNode);
 204         nodeOperands.set(x, operand);
 205         return operand;
 206     }
 207 
 208     /**
 209      * Used by the {@link MatchStatement} machinery to override the generation LIR for some
 210      * ValueNodes.
 211      */
 212     public void setMatchResult(Node x, Value operand) {
 213         assert operand.equals(ComplexMatchValue.INTERIOR_MATCH) || operand instanceof ComplexMatchValue;
 214         assert operand instanceof ComplexMatchValue || MatchPattern.isSingleValueUser(x) : "interior matches must be single user";
 215         assert nodeOperands != null && nodeOperands.get(x) == null : "operand cannot be set twice";
 216         assert !(x instanceof VirtualObjectNode);
 217         nodeOperands.set(x, operand);
 218     }
 219 
 220     public LabelRef getLIRBlock(FixedNode b) {
 221         assert gen.getResult().getLIR().getControlFlowGraph() instanceof ControlFlowGraph;
 222         Block result = ((ControlFlowGraph) gen.getResult().getLIR().getControlFlowGraph()).blockFor(b);
 223         int suxIndex = 0;
 224         for (AbstractBlockBase<?> succ : gen.getCurrentBlock().getSuccessors()) {
 225             if (succ == result) {
 226                 assert gen.getCurrentBlock() instanceof Block;
 227                 return LabelRef.forSuccessor(gen.getResult().getLIR(), gen.getCurrentBlock(), suxIndex);
 228             }
 229             suxIndex++;
 230         }
 231         throw GraalError.shouldNotReachHere("Block not in successor list of current block");
 232     }
 233 
 234     public final void append(LIRInstruction op) {
 235         if (Options.PrintIRWithLIR.getValue(nodeOperands.graph().getOptions()) && !TTY.isSuppressed()) {
 236             if (currentInstruction != null && lastInstructionPrinted != currentInstruction) {
 237                 lastInstructionPrinted = currentInstruction;
 238                 InstructionPrinter ip = new InstructionPrinter(TTY.out());
 239                 ip.printInstructionListing(currentInstruction);
 240             }
 241         }
 242         gen.append(op);
 243     }
 244 
 245     protected LIRKind getExactPhiKind(PhiNode phi) {
 246         LIRKind derivedKind = gen.toRegisterKind(gen.getLIRKind(phi.stamp()));
 247         /* Collect reference information. */
 248         for (int i = 0; i < phi.valueCount() && !derivedKind.isUnknownReference(); i++) {
 249             ValueNode node = phi.valueAt(i);
 250             Value value = getOperand(node);
 251 
 252             // get ValueKind for input
 253             final LIRKind valueKind;
 254             if (value != null) {
 255                 valueKind = value.getValueKind(LIRKind.class);
 256             } else {
 257                 assert isPhiInputFromBackedge(phi, i) : String.format("Input %s to phi node %s is not yet available although it is not coming from a loop back edge", node, phi);
 258                 LIRKind kind = gen.getLIRKind(node.stamp());
 259                 valueKind = gen.toRegisterKind(kind);
 260             }
 261             /* Merge the reference information of the derived kind and the input. */
 262             derivedKind = LIRKind.mergeReferenceInformation(derivedKind, valueKind);
 263         }
 264         return derivedKind;
 265     }
 266 
 267     private static boolean isPhiInputFromBackedge(PhiNode phi, int index) {
 268         AbstractMergeNode merge = phi.merge();
 269         AbstractEndNode end = merge.phiPredecessorAt(index);
 270         return end instanceof LoopEndNode && ((LoopEndNode) end).loopBegin().equals(merge);
 271     }
 272 
 273     private Value[] createPhiIn(AbstractMergeNode merge) {
 274         List<Value> values = new ArrayList<>();
 275         for (ValuePhiNode phi : merge.valuePhis()) {
 276             assert getOperand(phi) == null;
 277             Variable value = gen.newVariable(getExactPhiKind(phi));
 278             values.add(value);
 279             setResult(phi, value);
 280         }
 281         return values.toArray(new Value[values.size()]);
 282     }
 283 
 284     /**
 285      * @return {@code true} if object constant to stack moves are supported.
 286      */
 287     protected boolean allowObjectConstantToStackMove() {
 288         return true;
 289     }
 290 
 291     private Value[] createPhiOut(AbstractMergeNode merge, AbstractEndNode pred) {
 292         List<Value> values = new ArrayList<>();
 293         for (PhiNode phi : merge.valuePhis()) {
 294             ValueNode node = phi.valueAt(pred);
 295             Value value = operand(node);
 296             assert value != null;
 297             if (isRegister(value)) {
 298                 /*
 299                  * Fixed register intervals are not allowed at block boundaries so we introduce a
 300                  * new Variable.
 301                  */
 302                 value = gen.emitMove(value);
 303             } else if (!allowObjectConstantToStackMove() && node instanceof ConstantNode && !LIRKind.isValue(value)) {
 304                 /*
 305                  * Some constants are not allowed as inputs for PHIs in certain backends. Explicitly
 306                  * create a copy of this value to force it into a register. The new variable is only
 307                  * used in the PHI.
 308                  */
 309                 Variable result = gen.newVariable(value.getValueKind());
 310                 gen.emitMove(result, value);
 311                 value = result;
 312             }
 313             values.add(value);
 314         }
 315         return values.toArray(new Value[values.size()]);
 316     }
 317 
 318     @Override
 319     @SuppressWarnings("try")
 320     public void doBlock(Block block, StructuredGraph graph, BlockMap<List<Node>> blockMap) {
 321 
 322         OptionValues options = graph.getOptions();
 323         try (BlockScope blockScope = gen.getBlockScope(block)) {
 324             setSourcePosition(null);
 325 
 326             if (block == gen.getResult().getLIR().getControlFlowGraph().getStartBlock()) {
 327                 assert block.getPredecessorCount() == 0;
 328                 emitPrologue(graph);
 329             } else {
 330                 assert block.getPredecessorCount() > 0;
 331                 // create phi-in value array
 332                 AbstractBeginNode begin = block.getBeginNode();
 333                 if (begin instanceof AbstractMergeNode) {
 334                     AbstractMergeNode merge = (AbstractMergeNode) begin;
 335                     LabelOp label = (LabelOp) gen.getResult().getLIR().getLIRforBlock(block).get(0);
 336                     label.setPhiValues(createPhiIn(merge));
 337                     if (Options.PrintIRWithLIR.getValue(options) && !TTY.isSuppressed()) {
 338                         TTY.println("Created PhiIn: " + label);
 339 
 340                     }
 341                 }
 342             }
 343 
 344             List<Node> nodes = blockMap.get(block);
 345 
 346             // Allow NodeLIRBuilder subclass to specialize code generation of any interesting groups
 347             // of instructions
 348             matchComplexExpressions(nodes);
 349 
 350             boolean trace = traceLIRGeneratorLevel >= 3;
 351             for (int i = 0; i < nodes.size(); i++) {
 352                 Node node = nodes.get(i);
 353                 if (node instanceof ValueNode) {
 354                     ValueNode valueNode = (ValueNode) node;
 355                     if (trace) {
 356                         TTY.println("LIRGen for " + valueNode);
 357                     }
 358                     Value operand = getOperand(valueNode);
 359                     if (operand == null) {
 360                         if (!peephole(valueNode)) {
 361                             try {
 362                                 doRoot(valueNode);
 363                             } catch (GraalError e) {
 364                                 throw GraalGraphError.transformAndAddContext(e, valueNode);
 365                             } catch (Throwable e) {
 366                                 throw new GraalGraphError(e).addContext(valueNode);
 367                             }
 368                         }
 369                     } else if (ComplexMatchValue.INTERIOR_MATCH.equals(operand)) {
 370                         // Doesn't need to be evaluated
 371                         Debug.log("interior match for %s", valueNode);
 372                     } else if (operand instanceof ComplexMatchValue) {
 373                         Debug.log("complex match for %s", valueNode);
 374                         ComplexMatchValue match = (ComplexMatchValue) operand;
 375                         operand = match.evaluate(this);
 376                         if (operand != null) {
 377                             setResult(valueNode, operand);
 378                         }
 379                     } else {
 380                         // There can be cases in which the result of an instruction is already set
 381                         // before by other instructions.
 382                     }
 383                 }
 384             }
 385 
 386             if (!gen.hasBlockEnd(block)) {
 387                 NodeIterable<Node> successors = block.getEndNode().successors();
 388                 assert successors.count() == block.getSuccessorCount();
 389                 if (block.getSuccessorCount() != 1) {
 390                     /*
 391                      * If we have more than one successor, we cannot just use the first one. Since
 392                      * successors are unordered, this would be a random choice.
 393                      */
 394                     throw new GraalError("Block without BlockEndOp: " + block.getEndNode());
 395                 }
 396                 gen.emitJump(getLIRBlock((FixedNode) successors.first()));
 397             }
 398 
 399             assert verifyBlock(gen.getResult().getLIR(), block);
 400         }
 401     }
 402 
 403     @SuppressWarnings("try")
 404     protected void matchComplexExpressions(List<Node> nodes) {
 405         if (matchRules != null) {
 406             try (Scope s = Debug.scope("MatchComplexExpressions")) {
 407                 if (LogVerbose.getValue(nodeOperands.graph().getOptions())) {
 408                     int i = 0;
 409                     for (Node node : nodes) {
 410                         Debug.log("%d: (%s) %1S", i++, node.getUsageCount(), node);
 411                     }
 412                 }
 413 
 414                 // Match the nodes in backwards order to encourage longer matches.
 415                 for (int index = nodes.size() - 1; index >= 0; index--) {
 416                     Node node = nodes.get(index);
 417                     if (getOperand(node) != null) {
 418                         continue;
 419                     }
 420                     // See if this node is the root of any MatchStatements
 421                     List<MatchStatement> statements = matchRules.get(node.getClass());
 422                     if (statements != null) {
 423                         for (MatchStatement statement : statements) {
 424                             if (statement.generate(this, index, node, nodes)) {
 425                                 // Found a match so skip to the next
 426                                 break;
 427                             }
 428                         }
 429                     }
 430                 }
 431             }
 432         }
 433     }
 434 
 435     protected abstract boolean peephole(ValueNode valueNode);
 436 
 437     private void doRoot(ValueNode instr) {
 438         if (traceLIRGeneratorLevel >= 2) {
 439             TTY.println("Emitting LIR for instruction " + instr);
 440         }
 441         currentInstruction = instr;
 442 
 443         Debug.log("Visiting %s", instr);
 444         emitNode(instr);
 445         Debug.log("Operand for %s = %s", instr, getOperand(instr));
 446     }
 447 
 448     protected void emitNode(ValueNode node) {
 449         if (Debug.isLogEnabled() && node.stamp().isEmpty()) {
 450             Debug.log("This node has an empty stamp, we are emitting dead code(?): %s", node);
 451         }
 452         setSourcePosition(node.getNodeSourcePosition());
 453         if (node instanceof LIRLowerable) {
 454             ((LIRLowerable) node).generate(this);
 455         } else {
 456             throw GraalError.shouldNotReachHere("node is not LIRLowerable: " + node);
 457         }
 458     }
 459 
 460     protected void emitPrologue(StructuredGraph graph) {
 461         CallingConvention incomingArguments = gen.getResult().getCallingConvention();
 462 
 463         Value[] params = new Value[incomingArguments.getArgumentCount()];
 464         for (int i = 0; i < params.length; i++) {
 465             params[i] = incomingArguments.getArgument(i);
 466             if (ValueUtil.isStackSlot(params[i])) {
 467                 StackSlot slot = ValueUtil.asStackSlot(params[i]);
 468                 if (slot.isInCallerFrame() && !gen.getResult().getLIR().hasArgInCallerFrame()) {
 469                     gen.getResult().getLIR().setHasArgInCallerFrame();
 470                 }
 471             }
 472         }
 473 
 474         gen.emitIncomingValues(params);
 475 
 476         for (ParameterNode param : graph.getNodes(ParameterNode.TYPE)) {
 477             Value paramValue = params[param.index()];
 478             assert paramValue.getValueKind().equals(getLIRGeneratorTool().getLIRKind(param.stamp())) : paramValue + " " + getLIRGeneratorTool().getLIRKind(param.stamp());
 479             setResult(param, gen.emitMove(paramValue));
 480         }
 481     }
 482 
 483     @Override
 484     public void visitMerge(AbstractMergeNode x) {
 485     }
 486 
 487     @Override
 488     public void visitEndNode(AbstractEndNode end) {
 489         AbstractMergeNode merge = end.merge();
 490         JumpOp jump = newJumpOp(getLIRBlock(merge));
 491         jump.setPhiValues(createPhiOut(merge, end));
 492         append(jump);
 493     }
 494 
 495     /**
 496      * Runtime specific classes can override this to insert a safepoint at the end of a loop.
 497      */
 498     @Override
 499     public void visitLoopEnd(LoopEndNode x) {
 500     }
 501 
 502     protected JumpOp newJumpOp(LabelRef ref) {
 503         return new JumpOp(ref);
 504     }
 505 
 506     protected LIRKind getPhiKind(PhiNode phi) {
 507         return gen.getLIRKind(phi.stamp());
 508     }
 509 
 510     @Override
 511     public void emitIf(IfNode x) {
 512         emitBranch(x.condition(), getLIRBlock(x.trueSuccessor()), getLIRBlock(x.falseSuccessor()), x.probability(x.trueSuccessor()));
 513     }
 514 
 515     public void emitBranch(LogicNode node, LabelRef trueSuccessor, LabelRef falseSuccessor, double trueSuccessorProbability) {
 516         if (node instanceof IsNullNode) {
 517             emitNullCheckBranch((IsNullNode) node, trueSuccessor, falseSuccessor, trueSuccessorProbability);
 518         } else if (node instanceof CompareNode) {
 519             emitCompareBranch((CompareNode) node, trueSuccessor, falseSuccessor, trueSuccessorProbability);
 520         } else if (node instanceof LogicConstantNode) {
 521             emitConstantBranch(((LogicConstantNode) node).getValue(), trueSuccessor, falseSuccessor);
 522         } else if (node instanceof IntegerTestNode) {
 523             emitIntegerTestBranch((IntegerTestNode) node, trueSuccessor, falseSuccessor, trueSuccessorProbability);
 524         } else {
 525             throw GraalError.unimplemented(node.toString());
 526         }
 527     }
 528 
 529     private void emitNullCheckBranch(IsNullNode node, LabelRef trueSuccessor, LabelRef falseSuccessor, double trueSuccessorProbability) {
 530         LIRKind kind = gen.getLIRKind(node.getValue().stamp());
 531         Value nullValue = gen.emitConstant(kind, JavaConstant.NULL_POINTER);
 532         gen.emitCompareBranch(kind.getPlatformKind(), operand(node.getValue()), nullValue, Condition.EQ, false, trueSuccessor, falseSuccessor, trueSuccessorProbability);
 533     }
 534 
 535     public void emitCompareBranch(CompareNode compare, LabelRef trueSuccessor, LabelRef falseSuccessor, double trueSuccessorProbability) {
 536         PlatformKind kind = gen.getLIRKind(compare.getX().stamp()).getPlatformKind();
 537         gen.emitCompareBranch(kind, operand(compare.getX()), operand(compare.getY()), compare.condition(), compare.unorderedIsTrue(), trueSuccessor, falseSuccessor, trueSuccessorProbability);
 538     }
 539 
 540     public void emitIntegerTestBranch(IntegerTestNode test, LabelRef trueSuccessor, LabelRef falseSuccessor, double trueSuccessorProbability) {
 541         gen.emitIntegerTestBranch(operand(test.getX()), operand(test.getY()), trueSuccessor, falseSuccessor, trueSuccessorProbability);
 542     }
 543 
 544     public void emitConstantBranch(boolean value, LabelRef trueSuccessorBlock, LabelRef falseSuccessorBlock) {
 545         LabelRef block = value ? trueSuccessorBlock : falseSuccessorBlock;
 546         gen.emitJump(block);
 547     }
 548 
 549     @Override
 550     public void emitConditional(ConditionalNode conditional) {
 551         Value tVal = operand(conditional.trueValue());
 552         Value fVal = operand(conditional.falseValue());
 553         setResult(conditional, emitConditional(conditional.condition(), tVal, fVal));
 554     }
 555 
 556     public Variable emitConditional(LogicNode node, Value trueValue, Value falseValue) {
 557         if (node instanceof IsNullNode) {
 558             IsNullNode isNullNode = (IsNullNode) node;
 559             LIRKind kind = gen.getLIRKind(isNullNode.getValue().stamp());
 560             Value nullValue = gen.emitConstant(kind, JavaConstant.NULL_POINTER);
 561             return gen.emitConditionalMove(kind.getPlatformKind(), operand(isNullNode.getValue()), nullValue, Condition.EQ, false, trueValue, falseValue);
 562         } else if (node instanceof CompareNode) {
 563             CompareNode compare = (CompareNode) node;
 564             PlatformKind kind = gen.getLIRKind(compare.getX().stamp()).getPlatformKind();
 565             return gen.emitConditionalMove(kind, operand(compare.getX()), operand(compare.getY()), compare.condition(), compare.unorderedIsTrue(), trueValue, falseValue);
 566         } else if (node instanceof LogicConstantNode) {
 567             return gen.emitMove(((LogicConstantNode) node).getValue() ? trueValue : falseValue);
 568         } else if (node instanceof IntegerTestNode) {
 569             IntegerTestNode test = (IntegerTestNode) node;
 570             return gen.emitIntegerTestMove(operand(test.getX()), operand(test.getY()), trueValue, falseValue);
 571         } else {
 572             throw GraalError.unimplemented(node.toString());
 573         }
 574     }
 575 
 576     @Override
 577     public void emitInvoke(Invoke x) {
 578         LoweredCallTargetNode callTarget = (LoweredCallTargetNode) x.callTarget();
 579         CallingConvention invokeCc = gen.getResult().getFrameMapBuilder().getRegisterConfig().getCallingConvention(callTarget.callType(), x.asNode().stamp().javaType(gen.getMetaAccess()),
 580                         callTarget.signature(), gen);
 581         gen.getResult().getFrameMapBuilder().callsMethod(invokeCc);
 582 
 583         Value[] parameters = visitInvokeArguments(invokeCc, callTarget.arguments());
 584 
 585         LabelRef exceptionEdge = null;
 586         if (x instanceof InvokeWithExceptionNode) {
 587             exceptionEdge = getLIRBlock(((InvokeWithExceptionNode) x).exceptionEdge());
 588         }
 589         LIRFrameState callState = stateWithExceptionEdge(x, exceptionEdge);
 590 
 591         Value result = invokeCc.getReturn();
 592         if (callTarget instanceof DirectCallTargetNode) {
 593             emitDirectCall((DirectCallTargetNode) callTarget, result, parameters, AllocatableValue.NONE, callState);
 594         } else if (callTarget instanceof IndirectCallTargetNode) {
 595             emitIndirectCall((IndirectCallTargetNode) callTarget, result, parameters, AllocatableValue.NONE, callState);
 596         } else {
 597             throw GraalError.shouldNotReachHere();
 598         }
 599 
 600         if (isLegal(result)) {
 601             setResult(x.asNode(), gen.emitMove(result));
 602         }
 603 
 604         if (x instanceof InvokeWithExceptionNode) {
 605             gen.emitJump(getLIRBlock(((InvokeWithExceptionNode) x).next()));
 606         }
 607     }
 608 
 609     protected abstract void emitDirectCall(DirectCallTargetNode callTarget, Value result, Value[] parameters, Value[] temps, LIRFrameState callState);
 610 
 611     protected abstract void emitIndirectCall(IndirectCallTargetNode callTarget, Value result, Value[] parameters, Value[] temps, LIRFrameState callState);
 612 
 613     @Override
 614     public Value[] visitInvokeArguments(CallingConvention invokeCc, Collection<ValueNode> arguments) {
 615         // for each argument, load it into the correct location
 616         Value[] result = new Value[arguments.size()];
 617         int j = 0;
 618         for (ValueNode arg : arguments) {
 619             if (arg != null) {
 620                 AllocatableValue operand = invokeCc.getArgument(j);
 621                 gen.emitMove(operand, operand(arg));
 622                 result[j] = operand;
 623                 j++;
 624             } else {
 625                 throw GraalError.shouldNotReachHere("I thought we no longer have null entries for two-slot types...");
 626             }
 627         }
 628         return result;
 629     }
 630 
 631     /**
 632      * This method tries to create a switch implementation that is optimal for the given switch. It
 633      * will either generate a sequential if/then/else cascade, a set of range tests or a table
 634      * switch.
 635      *
 636      * If the given switch does not contain int keys, it will always create a sequential
 637      * implementation.
 638      */
 639     @Override
 640     public void emitSwitch(SwitchNode x) {
 641         assert x.defaultSuccessor() != null;
 642         LabelRef defaultTarget = getLIRBlock(x.defaultSuccessor());
 643         int keyCount = x.keyCount();
 644         if (keyCount == 0) {
 645             gen.emitJump(defaultTarget);
 646         } else {
 647             Variable value = gen.load(operand(x.value()));
 648             if (keyCount == 1) {
 649                 assert defaultTarget != null;
 650                 double probability = x.probability(x.keySuccessor(0));
 651                 LIRKind kind = gen.getLIRKind(x.value().stamp());
 652                 Value key = gen.emitConstant(kind, x.keyAt(0));
 653                 gen.emitCompareBranch(kind.getPlatformKind(), gen.load(operand(x.value())), key, Condition.EQ, false, getLIRBlock(x.keySuccessor(0)), defaultTarget, probability);
 654             } else if (x instanceof IntegerSwitchNode && x.isSorted()) {
 655                 IntegerSwitchNode intSwitch = (IntegerSwitchNode) x;
 656                 LabelRef[] keyTargets = new LabelRef[keyCount];
 657                 JavaConstant[] keyConstants = new JavaConstant[keyCount];
 658                 double[] keyProbabilities = new double[keyCount];
 659                 JavaKind keyKind = intSwitch.keyAt(0).getJavaKind();
 660                 for (int i = 0; i < keyCount; i++) {
 661                     keyTargets[i] = getLIRBlock(intSwitch.keySuccessor(i));
 662                     keyConstants[i] = intSwitch.keyAt(i);
 663                     keyProbabilities[i] = intSwitch.keyProbability(i);
 664                     assert keyConstants[i].getJavaKind() == keyKind;
 665                 }
 666                 gen.emitStrategySwitch(keyConstants, keyProbabilities, keyTargets, defaultTarget, value);
 667             } else {
 668                 // keyKind != JavaKind.Int || !x.isSorted()
 669                 LabelRef[] keyTargets = new LabelRef[keyCount];
 670                 Constant[] keyConstants = new Constant[keyCount];
 671                 double[] keyProbabilities = new double[keyCount];
 672                 for (int i = 0; i < keyCount; i++) {
 673                     keyTargets[i] = getLIRBlock(x.keySuccessor(i));
 674                     keyConstants[i] = x.keyAt(i);
 675                     keyProbabilities[i] = x.keyProbability(i);
 676                 }
 677 
 678                 // hopefully only a few entries
 679                 gen.emitStrategySwitch(new SwitchStrategy.SequentialStrategy(keyProbabilities, keyConstants), value, keyTargets, defaultTarget);
 680             }
 681         }
 682     }
 683 
 684     public DebugInfoBuilder getDebugInfoBuilder() {
 685         assert debugInfoBuilder != null;
 686         return debugInfoBuilder;
 687     }
 688 
 689     private static FrameState getFrameState(DeoptimizingNode deopt) {
 690         if (deopt instanceof DeoptimizingNode.DeoptBefore) {
 691             assert !(deopt instanceof DeoptimizingNode.DeoptDuring || deopt instanceof DeoptimizingNode.DeoptAfter);
 692             return ((DeoptimizingNode.DeoptBefore) deopt).stateBefore();
 693         } else if (deopt instanceof DeoptimizingNode.DeoptDuring) {
 694             assert !(deopt instanceof DeoptimizingNode.DeoptAfter);
 695             return ((DeoptimizingNode.DeoptDuring) deopt).stateDuring();
 696         } else {
 697             assert deopt instanceof DeoptimizingNode.DeoptAfter;
 698             return ((DeoptimizingNode.DeoptAfter) deopt).stateAfter();
 699         }
 700     }
 701 
 702     @Override
 703     public LIRFrameState state(DeoptimizingNode deopt) {
 704         if (!deopt.canDeoptimize()) {
 705             return null;
 706         }
 707         return stateFor(getFrameState(deopt));
 708     }
 709 
 710     public LIRFrameState stateWithExceptionEdge(DeoptimizingNode deopt, LabelRef exceptionEdge) {
 711         if (!deopt.canDeoptimize()) {
 712             return null;
 713         }
 714         return stateForWithExceptionEdge(getFrameState(deopt), exceptionEdge);
 715     }
 716 
 717     public LIRFrameState stateFor(FrameState state) {
 718         return stateForWithExceptionEdge(state, null);
 719     }
 720 
 721     public LIRFrameState stateForWithExceptionEdge(FrameState state, LabelRef exceptionEdge) {
 722         if (gen.needOnlyOopMaps()) {
 723             return new LIRFrameState(null, null, null);
 724         }
 725         assert state != null;
 726         return getDebugInfoBuilder().build(state, exceptionEdge);
 727     }
 728 
 729     @Override
 730     public void emitOverflowCheckBranch(AbstractBeginNode overflowSuccessor, AbstractBeginNode next, Stamp stamp, double probability) {
 731         LIRKind cmpKind = getLIRGeneratorTool().getLIRKind(stamp);
 732         gen.emitOverflowCheckBranch(getLIRBlock(overflowSuccessor), getLIRBlock(next), cmpKind, probability);
 733     }
 734 
 735     @Override
 736     public void visitFullInfopointNode(FullInfopointNode i) {
 737         append(new FullInfopointOp(stateFor(i.getState()), i.getReason()));
 738     }
 739 
 740     @Override
 741     public void setSourcePosition(NodeSourcePosition position) {
 742         gen.setSourcePosition(position);
 743     }
 744 
 745     @Override
 746     public LIRGeneratorTool getLIRGeneratorTool() {
 747         return gen;
 748     }
 749 }