Add fast negative checks for symbol equality: If we're comparing...

src/date-delay.js

 // Copyright 2006-2008 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 132 matching lines @@
 var DST_offset_cache = {
   // Cached DST offset.
   offset: 0,
   // Time interval where the cached offset is valid.
   start: 0, end: -1,
   // Size of next interval expansion.
   increment: 0
 };
 
 
+// NOTE: The implementation relies on the fact that no time zones have
+// more than one daylight savings offset change per month.
 function DaylightSavingsOffset(t) {
   // Load the cache object from the builtins object.
   var cache = DST_offset_cache;
 
   // Cache the start and the end in local variables for fast access.
   var start = cache.start;
   var end = cache.end;
 
   if (start <= t) {
     // If the time fits in the cached interval, return the cached offset.
@@ skipping 360 matching lines @@
 function GetUTCHoursFrom(aDate) {
   var t = GetTimeFrom(aDate);
   if ($isNaN(t)) return t;
   return HourFromTime(t);
 }
 
 
 function GetFullYearFrom(aDate) {
   var t = GetTimeFrom(aDate);
   if ($isNaN(t)) return t;
-  return YearFromTime(LocalTimeNoCheck(t));
+  // Ignore the DST offset for year computations.
+  return YearFromTime(t + local_time_offset);
 }
 
 
 function GetUTCFullYearFrom(aDate) {
   var t = GetTimeFrom(aDate);
   if ($isNaN(t)) return t;
   return YearFromTime(t);
 }
 
 
@@ skipping 578 matching lines @@
     "toGMTString", DateToGMTString,
     "toUTCString", DateToUTCString,
     "getYear", DateGetYear,
     "setYear", DateSetYear,
     "toISOString", DateToISOString,
     "toJSON", DateToJSON
   ));
 }
 
 SetupDate();