Implement simple dynamic type check.

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 2071 matching lines @@
     // However it turns out that inserting an integer check in the optimized
     // version is cheaper than having another bailout case. This is true,
     // because the integer check will simply throw if it fails.
     return HType.UNKNOWN;
   }
 
   bool get builtin() => receiver.isMutableArray() && index.isInteger();
 }
 
 class HIs extends HInstruction {
-  final Type typeName;
+  final Type typeExpression;

[kasperl, 2012/04/30 08:48:32]

It really isn't an expression but I guess it isn't a name either.

[karlklose, 2012/05/01 11:20:55]

This is actually reverting a renaming from an earlier CL.

   final bool nullOk;
 
-  HIs(this.typeName, HInstruction expression, [nullOk = false])
-    : this.nullOk = nullOk, super(<HInstruction>[expression]);
+  HIs.withTypeInfo(this.typeExpression, HInstruction expression,

[ngeoffray, 2012/04/30 08:51:12]

withTypeInfoCall?

[karlklose, 2012/05/01 11:20:55]

Done.

+                   HInstruction typeInfo, [nullOk = false])

[kasperl, 2012/04/30 08:48:32]

Can't we use this.nullOk in the parameter list?

[karlklose, 2012/05/01 11:20:55]

Done.

+    : this.nullOk = nullOk, super(<HInstruction>[expression, typeInfo]);
+
+  HIs(this.typeExpression, HInstruction expression, [nullOk = false])
+     : this.nullOk = nullOk, super(<HInstruction>[expression]);
 
   HInstruction get expression() => inputs[0];
 
+  HInstruction get typeInfo() => inputs[1];

[ngeoffray, 2012/04/30 08:51:12]

ditto

[karlklose, 2012/05/01 11:20:55]

Done.

+
   HType get guaranteedType() => HType.BOOLEAN;
 
   accept(HVisitor visitor) => visitor.visitIs(this);
 
-  toString() => "$expression is $typeName";
+  toString() => "$expression is $typeExpression";
 }
 
 
 interface HBlockInformation {
   bool accept(HBlockInformationVisitor visitor);
 }
 
 interface HBlockInformationVisitor {
   bool visitLabeledBlockInfo(HLabeledBlockInformation info);
   bool visitLoopInfo(HLoopInformation info);
@@ skipping 115 matching lines @@
   final bool isAnd;
   final SubExpression left;
   final SubExpression right;
   final HBasicBlock joinBlock;
   HAndOrBlockInformation(this.isAnd,
                          this.left,
                          this.right,
                          this.joinBlock);
   bool accept(HBlockInformationVisitor visitor) => visitor.visitAndOrInfo(this);
 }