ARM: Use ubfx and movw instructions to avoid a PC-relative load on

src/platform-linux.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 578 matching lines @@
 static const int kMmapFdOffset = 0;
 
 VirtualMemory::VirtualMemory() : address_(NULL), size_(0) { }
 
 VirtualMemory::VirtualMemory(size_t size) {
   address_ = ReserveRegion(size);
   size_ = size;
 }
 
 
-VirtualMemory::VirtualMemory(size_t size, size_t alignment)
+VirtualMemory::VirtualMemory(size_t size, size_t alignment, intptr_t preferred)
     : address_(NULL), size_(0) {
   ASSERT(IsAligned(alignment, static_cast<intptr_t>(OS::AllocateAlignment())));
   size_t request_size = RoundUp(size + alignment,
                                 static_cast<intptr_t>(OS::AllocateAlignment()));
-  void* reservation = mmap(OS::GetRandomMmapAddr(),
+  void* reservation = mmap(preferred == 0 ?
+                               OS::GetRandomMmapAddr() :
+                               reinterpret_cast<void*>(preferred),
                            request_size,
                            PROT_NONE,
                            MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE,
                            kMmapFd,
                            kMmapFdOffset);
   if (reservation == MAP_FAILED) return;
 
   Address base = static_cast<Address>(reservation);
   Address aligned_base = RoundUp(base, alignment);
   ASSERT_LE(base, aligned_base);
@@ skipping 625 matching lines @@
 
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SignalSender::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 
 } }  // namespace v8::internal