Fix a long-standing bug in the computation of the live environments for bailouts. When visiting a l…

frog/leg/ssa/nodes.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 interface HVisitor<R> {
   R visitAdd(HAdd node);
   R visitBailoutTarget(HBailoutTarget node);
   R visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
@@ skipping 380 matching lines @@
   bool contains(HInstruction instruction) {
     HInstruction cursor = first;
     while (cursor != null) {
       if (cursor === instruction) return true;
       cursor = cursor.next;
     }
     return false;
   }
 }
 
-class HBasicBlock extends HInstructionList {
+class HBasicBlock extends HInstructionList implements Hashable {
   // The [id] must be such that any successor's id is greater than
   // this [id]. The exception are back-edges.
   int id;
 
   static final int STATUS_NEW = 0;
   static final int STATUS_OPEN = 1;
   static final int STATUS_CLOSED = 2;
   int status = STATUS_NEW;
 
   HInstructionList phis;
@@ skipping 13 matching lines @@
   List<SourceString> labels;
 
   HBasicBlock() : this.withId(null);
   HBasicBlock.withId(this.id)
       : phis = new HInstructionList(),
         predecessors = <HBasicBlock>[],
         successors = const <HBasicBlock>[],
         dominatedBlocks = <HBasicBlock>[],
         bailouts = <HBailoutTarget>[];
 
+  int hashCode() => id;
+
   bool isNew() => status == STATUS_NEW;
   bool isOpen() => status == STATUS_OPEN;
   bool isClosed() => status == STATUS_CLOSED;
 
   bool isLoopHeader() => loopInformation !== null;
   bool hasLabeledBlockInformation() => labeledBlockInformation !== null;
 
   bool hasBailouts() => !bailouts.isEmpty();
 
   void open() {
@@ skipping 1675 matching lines @@
 class HIfBlockInformation {
   final HIf branch;
   final SubGraph thenGraph;
   final SubGraph elseGraph;
   final HBasicBlock joinBlock;
   HIfBlockInformation(this.branch,
                       this.thenGraph,
                       this.elseGraph,
                       this.joinBlock);
 }