Load elimination fix: load should not be replaced with another load if the former is not dominated …

test/mjsunit/compiler/load-elimination.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 25 matching lines @@
 }
 
 function C() {
 }
 
 function test_load() {
   var a = new B(1, 2);
   return a.x + a.x + a.x + a.x;
 }
 
+
+function test_load_from_different_contexts() {
+  var r = 1;
+  this.f = function() {
+    var fr = r;
+    this.g = function(flag) {
+      var gr;
+      if (flag) {
+        gr = r;
+      } else {
+        gr = r;
+      }
+      return gr + r + fr;
+    };
+  };
+  this.f();
+  return this.g(true);
+}
+
+
 function test_store_load() {
   var a = new B(1, 2);
   a.x = 4;
   var f = a.x;
   a.x = 5;
   var g = a.x;
   a.x = 6;
   var h = a.x;
   a.x = 7;
   return f + g + h + a.x;
@@ skipping 65 matching lines @@
 }
 
 function test(x, f) {
   assertEquals(x, f());
   assertEquals(x, f());
   %OptimizeFunctionOnNextCall(f);
   assertEquals(x, f());
 }
 
 test(4, test_load);
+test(3, new test_load_from_different_contexts().g);
 test(22, test_store_load);
 test(8, test_nonaliasing_store1);
 test(5, test_transitioning_store1);
 test(4, test_transitioning_store2);
 test(20, test_transitioning_store3);
 test(22, test_store_load_kill);
 test(7, test_store_store);