Reapply change to GVN all HFieldGet instructions.

lib/compiler/implementation/ssa/tracer.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, 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.
 
 #library('tracer');
 
 #import('dart:io');
 #import('ssa.dart');
 #import('../leg.dart');
 
 final bool GENERATE_SSA_TRACE = false;
@@ skipping 53 matching lines @@
     }
   }
 
   void addInstructions(HInstructionStringifier stringifier,
                        HInstructionList list) {
     for (HInstruction instruction = list.first;
          instruction !== null;
          instruction = instruction.next) {
       int bci = 0;
       int uses = instruction.usedBy.length;
+      String changes = instruction.hasSideEffects() ? '!' : ' ';
+      String depends = instruction.dependsOnSomething() ? '?' : '';
       addIndent();
       String temporaryId = stringifier.temporaryId(instruction);
       String instructionString = stringifier.visit(instruction);
-      add("$bci $uses $temporaryId $instructionString <|@\n");
+      add("$bci $uses $temporaryId $instructionString $changes $depends <|@\n");
     }
   }
 
   void visitBasicBlock(HBasicBlock block) {
     HInstructionStringifier stringifier = new HInstructionStringifier(block);
     assert(block.id !== null);
     tag("block", () {
       printProperty("name", "B${block.id}");
       printProperty("from_bci", -1);
       printProperty("to_bci", -1);
@@ skipping 355 matching lines @@
       case HType.INDEXABLE_PRIMITIVE: type = "string_or_array"; break;
       case HType.UNKNOWN: type = 'unknown'; break;
       default:
         // TODO(floitsch): Need a compiler object.
         compiler.internalError('Unexpected type guard.',
                                instruction: node.guardedType);
         break;
     }
     StringBuffer envBuffer = new StringBuffer();
     List<HInstruction> inputs = node.inputs;
-    // The last input is the guarded expression.
-    for (int i = 0; i < inputs.length - 1; i++) {
-      envBuffer.add(" ${temporaryId(inputs[i])}");
+    for (int i = 0; i < inputs.length; i++) {
+      if (inputs[i] !== node.guarded) {

[ngeoffray, 2012/06/15 19:45:33]

Thanks, good catch.

+        envBuffer.add(" ${temporaryId(inputs[i])}");
+      }
     }
     String on = node.isOn ? "on" : "off";
     String id = temporaryId(node.guarded);
     return "TypeGuard($on): $id is $type env: $envBuffer";
   }
 
   String visitIs(HIs node) {
     String type = node.typeExpression.toString();
     return "TypeTest: ${temporaryId(node.expression)} is $type";
   }
 
   String visitTypeConversion(HTypeConversion node) {
     String type = node.propagatedType.toString();
     return "TypeConversion: ${temporaryId(node.inputs[0])} to $type";
   }
 }