Recognize logical operations before code generation.

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 908 matching lines @@
     }
   }
 
   bool isConstant() => false;
   bool isConstantBoolean() => false;
   bool isConstantNull() => false;
   bool isConstantNumber() => false;
   bool isConstantString() => false;
   bool isConstantList() => false;
   bool isConstantMap() => false;
+  bool isConstantFalse() => false;
+  bool isConstantTrue() => false;
 
   bool isValid() {
     HValidator validator = new HValidator();
     validator.currentBlock = block;
     validator.visitInstruction(this);
     return validator.isValid;
   }
 
   /**
    * The code for computing a bailout environment, and the code
@@ skipping 795 matching lines @@
 
   HType get guaranteedType() => constantType;
 
   bool isConstant() => true;
   bool isConstantBoolean() => constant.isBool();
   bool isConstantNull() => constant.isNull();
   bool isConstantNumber() => constant.isNum();
   bool isConstantString() => constant.isString();
   bool isConstantList() => constant.isList();
   bool isConstantMap() => constant.isMap();
+  bool isConstantFalse() => constant.isFalse();
+  bool isConstantTrue() => constant.isTrue();
 
   // Maybe avoid this if the literal is big?
   bool isCodeMotionInvariant() => true;
 }
 
 class HNot extends HInstruction {
   HNot(HInstruction value) : super(<HInstruction>[value]);
   void prepareGvn() {
     assert(!hasSideEffects());
     setUseGvn();
@@ skipping 725 matching lines @@
                        this.catchBlock,
                        this.finallyBlock);
 
   HBasicBlock get start() => body.start;
   HBasicBlock get end() =>
       finallyBlock === null ? catchBlock.end : finallyBlock.end;
 
   bool accept(HStatementInformationVisitor visitor) =>
     visitor.visitTryInfo(this);
 }