Don't rely on any speculative type in the bailout version.

lib/compiler/implementation/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 visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
   R visitBitXor(HBitXor node);
@@ skipping 1049 matching lines @@
 class HCheck extends HInstruction {
   HCheck(inputs) : super(inputs);
 
   // TODO(floitsch): make class abstract instead of adding an abstract method.
   abstract accept(HVisitor visitor);
 
   bool isControlFlow() => true;
 }
 
 class HTypeGuard extends HInstruction {
-  int state;
-  HTypeGuard(int this.state, List<HInstruction> env) : super(env);
+  final int state;
+  final HType guardedType;
+  bool isActive = false;

[ngeoffray, 2012/04/18 12:05:09]

Not sure, but for me isOn conveys more what this is doing.

[floitsch, 2012/04/18 17:18:46]

Done.

+  HTypeGuard(this.guardedType, this.state, List<HInstruction> env) : super(env);
 
   void prepareGvn() {
     assert(!hasSideEffects());
     setUseGvn();
   }
 
   HInstruction get guarded() => inputs.last();
 
+  HType computeTypeFromInputTypes() {
+    if (isActive) return guardedType;

[kasperl, 2012/04/18 11:46:15]

return isActive ? guardedType : guarded.propagatedType;

[floitsch, 2012/04/18 17:18:46]

Done.

+    return guarded.propagatedType;
+  }
+
+  HType get guaranteedType() => isActive ? guardedType : HType.UNKNOWN;
+
   bool isControlFlow() => true;
 
   accept(HVisitor visitor) => visitor.visitTypeGuard(this);
   int typeCode() => 1;
   bool typeEquals(other) => other is HTypeGuard;
-  bool dataEquals(HTypeGuard other) => propagatedType == other.propagatedType;
+  bool dataEquals(HTypeGuard other) => guardedType == other.guardedType;
 }
 
 class HBoundsCheck extends HCheck {
   HBoundsCheck(length, index) : super(<HInstruction>[length, index]);
 
   HInstruction get length() => inputs[0];
   HInstruction get index() => inputs[1];
 
   void prepareGvn() {
     assert(!hasSideEffects());
@@ skipping 315 matching lines @@
   HType computeDesiredTypeForNonTargetInput(HInstruction input) {
     // If the desired output type should be an integer we want to get two
     // integers as arguments.
     if (propagatedType.isInteger()) return HType.INTEGER;
     // If the outgoing type should be a number we can get that if both inputs
     // are numbers. If we don't know the outgoing type we try to make it a
     // number.
     if (propagatedType.isUnknown() || propagatedType.isNumber()) {
       return HType.NUMBER;
     }
+    // Even if the desired outgoing type is not a number we still want the
+    // second argument to be a number if the first one is a number. This will
+    // not help for the outgoing type, but at least the binary arithmetic
+    // operation will not have type problems.
+    // TODO(floitsch): normally we shouldn't request a number, but simply
+    // throw an IllegalArgumentException if it isn't. This would be similar
+    // to the array case.
+    if (input == right && left.isNumber()) return HType.NUMBER;
     return HType.UNKNOWN;
   }
 
   HType get likelyType() {
     if (left.isTypeUnknown()) return HType.NUMBER;
     return HType.UNKNOWN;
   }
 
   // TODO(1603): The class should be marked as abstract.
   abstract BinaryOperation get operation();
@@ skipping 795 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);
 }