Use the correct inputs when checking if inverse operator can be used.

lib/compiler/implementation/ssa/codegen.dart

 // 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.
 
 class SsaCodeGeneratorTask extends CompilerTask {
 
   final JavaScriptBackend backend;
 
   SsaCodeGeneratorTask(JavaScriptBackend backend)
       : this.backend = backend,
@@ skipping 1782 matching lines @@
       if (instruction is !HRelational) return false;
       HRelational relational = instruction;
       return relational.isBuiltin(types);
     }
 
     if (input is HBoolify && isGenerateAtUseSite(input)) {
       use(input.inputs[0]);
       push(new js.Binary("!==", pop(), new js.LiteralBool(true)), input);
     } else if (isBuiltinRelational(input) &&
                isGenerateAtUseSite(input) &&
-               types[input.inputs[0]].isUseful() &&
-               !input.inputs[0].isDouble(types) &&
                types[input.inputs[1]].isUseful() &&

[floitsch, 2012/10/04 11:35:26]

I really think we should make this input.left, input.right.

-               !input.inputs[1].isDouble(types)) {
+               !input.inputs[1].isDouble(types) &&
+               types[input.inputs[2]].isUseful() &&
+               !input.inputs[2].isDouble(types)) {
       // This optimization doesn't work for NaN, so we only do it if the
       // type is known to be non-Double.
       Map<String, String> inverseOperator = const <String, String>{
         "==" : "!=",
         "!=" : "==",
         "===": "!==",
         "!==": "===",
         "<"  : ">=",
         "<=" : ">",
         ">"  : "<=",
         ">=" : "<"
       };
       HRelational relational = input;
-      
-      visitInvokeBinary(input,
-                        inverseOperator[relational.operation.name.stringValue]);
+      BinaryOperation operation = relational.operation(backend.constantSystem);
+      visitInvokeBinary(input, inverseOperator[operation.name.stringValue]);
     } else {
       use(input);
       push(new js.Prefix("!", pop()));
     }
   }
 
   visitParameterValue(HParameterValue node) => visitLocalValue(node);
 
   visitLocalValue(HLocalValue node) {
     assert(isGenerateAtUseSite(node));
@@ skipping 1151 matching lines @@
   if (leftType.canBeNull() && rightType.canBeNull()) {
     if (left.isConstantNull() || right.isConstantNull() ||
         (leftType.isPrimitive() && leftType == rightType)) {
       return '==';
     }
     return null;
   } else {
     return '===';
   }
 }