Fix performance regressions due to lazy initialization.

src/platform-cygwin.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 55 matching lines @@
   // Convert the current time to a 64-bit integer first, before converting it
   // to an unsigned. Going directly can cause an overflow and the seed to be
   // set to all ones. The seed will be identical for different instances that
   // call this setup code within the same millisecond.
   uint64_t seed = static_cast<uint64_t>(TimeCurrentMillis());
   srandom(static_cast<unsigned int>(seed));
   limit_mutex = CreateMutex();
 }
 
 
+void MathSetup();  // Defined in platform-posix.cc.

[danno, 2012/03/29 12:32:42]

I really don't like having this external declaration here. It seems like
overkill to create a platform-posix.h just to contain it, but I think I might
prefer it to the multiple platform-specific declarations.

[Philippe, 2012/03/29 13:06:53]

Done. Indeed. platform-posix.h might also serve later.

+
+void OS::PostSetUp() {
+  // Math functions depend on CPU features therefore they are initialized after
+  // CPU.
+  MathSetup();
+}
+
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
   return 0;  // Nothing special about Cygwin.
 }
 
 
 int OS::ActivationFrameAlignment() {
   // With gcc 4.4 the tree vectorization optimizer can generate code
   // that requires 16 byte alignment such as movdqa on x86.
   return 16;
 }
@@ skipping 675 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SamplerThread::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal