OS::TimeCurrentMillis should return double not long double

src/platform-posix.cc

 // Copyright 2012 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 302 matching lines @@
   if (getrusage(RUSAGE_SELF, &usage) < 0) return -1;
   *secs = usage.ru_utime.tv_sec;
   *usecs = usage.ru_utime.tv_usec;
   return 0;
 }
 
 
 double OS::TimeCurrentMillis() {
   struct timeval tv;
   if (gettimeofday(&tv, NULL) < 0) return 0.0;
-  return (static_cast<double>(tv.tv_sec) * 1000) +
-         (static_cast<double>(tv.tv_usec) / 1000);
+  volatile double result =
+      (static_cast<double>(tv.tv_sec) * 1000) +
+      (static_cast<double>(tv.tv_usec) / 1000);
+  return result;
 }
 
 
 int64_t OS::Ticks() {
   // gettimeofday has microsecond resolution.
   struct timeval tv;
   if (gettimeofday(&tv, NULL) < 0)
     return 0;
   return (static_cast<int64_t>(tv.tv_sec) * 1000000) + tv.tv_usec;
 }
@@ skipping 655 matching lines @@
   return ntohl(value);
 }
 
 
 Socket* OS::CreateSocket() {
   return new POSIXSocket();
 }
 
 
 } }  // namespace v8::internal