Remove remaining uses of null's absolute address from non-IA32.

runtime/vm/assembler_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // NOLINT
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
 #include "vm/runtime_entry.h"
 #include "vm/simulator.h"
 #include "vm/stack_frame.h"
 #include "vm/stub_code.h"
 
 // An extra check since we are assuming the existence of /proc/cpuinfo below.
 #if !defined(USING_SIMULATOR) && !defined(__linux__) && !defined(ANDROID)
 #error ARM cross-compile only supported on Linux
 #endif
 
 namespace dart {
 
+DECLARE_FLAG(bool, allow_absolute_addresses);
 DEFINE_FLAG(bool, print_stop_message, true, "Print stop message.");
 DECLARE_FLAG(bool, inline_alloc);
 
 // Instruction encoding bits.
 enum {
   H   = 1 << 5,   // halfword (or byte)
   L   = 1 << 20,  // load (or store)
   S   = 1 << 20,  // set condition code (or leave unchanged)
   W   = 1 << 21,  // writeback base register (or leave unchanged)
   A   = 1 << 21,  // accumulate in multiply instruction (or not)
@@ skipping 1543 matching lines @@
   // Load common VM constants from the thread. This works also in places where
   // no constant pool is set up (e.g. intrinsic code).
   if (Thread::CanLoadFromThread(object)) {
     ldr(rd, Address(THR, Thread::OffsetFromThread(object)), cond);
     return;
   }
   // Smis and VM heap objects are never relocated; do not use object pool.
   if (object.IsSmi()) {
     LoadImmediate(rd, reinterpret_cast<int32_t>(object.raw()), cond);
   } else if (object.InVMHeap() || !constant_pool_allowed()) {
+    ASSERT(FLAG_allow_absolute_addresses);
     // Make sure that class CallPattern is able to decode this load immediate.
     const int32_t object_raw = reinterpret_cast<int32_t>(object.raw());
     LoadImmediate(rd, object_raw, cond);
   } else {
     // Make sure that class CallPattern is able to decode this load from the
     // object pool.
     const int32_t offset = ObjectPool::element_offset(
        is_unique ? object_pool_wrapper_.AddObject(object)
                  : object_pool_wrapper_.FindObject(object));
     LoadWordFromPoolOffset(rd, offset - kHeapObjectTag, cond);
@@ skipping 174 matching lines @@
       b(&ok, EQ);
       Stop("Expected heap object or Smi");
       break;
     case kEmptyOrSmiOrNull:
       b(&ok, EQ);  // Smi is OK.
       // Non-smi case: Check for the special zap word or null.
       // Note: Cannot use CompareImmediate, since IP may be in use.
       LoadImmediate(temp, Heap::kZap32Bits);
       cmp(old_value, Operand(temp));
       b(&ok, EQ);
-      LoadImmediate(temp, reinterpret_cast<uint32_t>(Object::null()));
+      LoadObject(temp, Object::null_object());
       cmp(old_value, Operand(temp));
       b(&ok, EQ);
       Stop("Expected zapped, Smi or null");
       break;
     default:
       UNREACHABLE();
   }
   Bind(&ok);
   if (VerifiedMemory::enabled()) {
     Operand shadow_offset(GetVerifiedMemoryShadow());
@@ skipping 1589 matching lines @@
 
 
 void Assembler::LoadAllocationStatsAddress(Register dest,
                                            intptr_t cid,
                                            bool inline_isolate) {
   ASSERT(dest != kNoRegister);
   ASSERT(dest != TMP);
   ASSERT(cid > 0);
   const intptr_t class_offset = ClassTable::ClassOffsetFor(cid);
   if (inline_isolate) {
+    ASSERT(FLAG_allow_absolute_addresses);
     ClassTable* class_table = Isolate::Current()->class_table();
     ClassHeapStats** table_ptr = class_table->TableAddressFor(cid);
     if (cid < kNumPredefinedCids) {
       LoadImmediate(dest, reinterpret_cast<uword>(*table_ptr) + class_offset);
     } else {
       LoadImmediate(dest, reinterpret_cast<uword>(table_ptr));
       ldr(dest, Address(dest, 0));
       AddImmediate(dest, class_offset);
     }
   } else {
@@ skipping 263 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfFpuRegisters));
   return fpu_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM